Glossary
- Page ID
- 96981
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Comprehensive Glossary
| Word(s) | Definition |
|---|---|
| 12-Step Facilitation Therapy (TSF) | An individual therapy that introduces clients to the core principles of 12-step programs and motivates them to become actively involved in fellowship meetings to maintain sobriety and reduce relapse risk. |
| Abstinence | The Centers for Disease Control and Prevention (CDC) defines abstinence as not having vaginal, oral, or anal sex. |
| Acceptable Macronutrient Distribution Ranges (AMDRs) | One of the standards that make up the Dietary Reference Intakes; recommended intake ranges for protein, fat, and carbohydrates as percentages of total daily calories. |
| Acrophobia | An intense fear of heights that triggers anxiety or panic in high places, often treated with therapy or relaxation techniques. |
| Actin Myofilaments | Thin protein filaments found in muscle fibers. Actin is also involved in maintaining the structure and shape of the muscle fiber. |
| Action Potential | An electrical signal that travels along a neuron or muscle cell, triggered by a change in the cell’s membrane potential. Action potentials are essential for nerve function, muscle movement, and various physiological processes. |
| Active Stretching | A type of stretching where the individual uses their own muscles to hold a stretch without the assistance of an external force. |
| Activities of Daily Living (ADLs) | Basic self-care tasks, such as bathing, dressing, and household chores, that physical activity can help older adults perform more easily and independently |
| Acute Sleep Deprivation | Short-term, temporary loss of sleep that impairs performance, alertness, and mood. |
| Acute Stress | A short-term physiological and psychological response to an immediate perceived threat or challenge. |
| Adaptations | The physiological changes that occur in the body in response to consistent physical activity or training. These adaptations can include increased cardiovascular efficiency, improved muscular strength and endurance, enhanced flexibility, and better metabolic function, all of which help the body perform exercise more efficiently over time. |
| Added Sugars | Sugars and syrups that are added to foods or beverages during processing or preparation. This includes ingredients like table sugar, honey, syrups, and sweeteners added during cooking, baking, or manufacturing. |
| Addiction | A brain disease that results in the inability to stop using a drug or engaging in a behavior, even when it causes physical, emotional, social, or legal problems. |
| Adenosine Triphosphate | Is the basic form of cellular energy found in the body. The energy source for cellular processes. |
| Adenosine Triphosphate (ATP) | The primary energy carrier in cells, fueling essential biological processes like muscle contraction, nerve signaling, and metabolism. It releases energy when its high-energy phosphate bonds are broken. |
| Adequate Intakes (AIs) | Recommended average daily nutrient intake levels based on observed or experimentally determined estimates of nutrient consumption when scientific evidence is insufficient to establish a Recommended Dietary Allowance (RDA). They are used as a guide to ensure nutritional adequacy. |
| Adipose (Fat) tissue | A type of connective tissue that stores energy in the form of fat and provides insulation and cushioning for the body. It also functions as an endocrine organ by releasing hormones that influence metabolism and appetite. |
| Adipose Tissue | Body fat that makes up the fat mass in body composition; includes subcutaneous (under skin) and visceral (around organs) fat. |
| Adrenaline (Epinephrine) | A hormone and neurotransmitter released by the adrenal glands during stress or excitement that increases heart rate, blood pressure, and energy availability. |
| Aerobic Exercise | Continuous, rhythmic physical activity that uses large muscle groups and relies primarily on oxygen for energy production. |
| Aerobic Metabolism | Produces ATP using oxygen to break down glucose, fats, and proteins. It provides sustained energy for endurance activities and produces carbon dioxide and water as byproducts. |
| Agility | The ability to rapidly change direction, speed, or position of the body with control and efficiency. It involves a combination of balance, coordination, reaction time, and quickness, making it essential for sports and activities that require sudden movements and adjustments. |
| Agonist | An agonist is the muscle that contracts to produce a specific movement. |
| Agoraphobia | An anxiety disorder characterized by an intense fear of situations where escape may be difficult or help unavailable, often leading to avoidance of crowded places, public transportation, or open spaces. |
| Agreeableness | A personality trait reflecting compassion, cooperation, trust, and a tendency to prioritize social harmony. |
| Alcohol | Ethanol, the intoxicating ingredient in beer, wine, and spirits that provides 7 calories per gram. It is not essential for health, and excessive intake can lead to serious health problems. |
| Alcoholic Hepatitis | A condition characterized by inflammation and damage to liver cells as a direct result of chronic alcohol use, often accompanied by fatty liver and fibrosis, and in severe cases, may progress to cirrhosis or liver failure. |
| Allostatic Load | The cumulative wear and tear on the body’s systems caused by chronic stress and repeated activation of the stress response. |
| Alpha-linolenic acid (18:3) | An essential omega-3 fatty acid found mainly in plant sources such as flaxseed, chia seeds, walnuts, and canola oil. The body cannot produce ALA, so it must come from the diet and can be partially converted into other omega-3 fats like EPA and DHA. |
| Alström | syndrome**: A rare inherited disorder causing vision and hearing loss, obesity, diabetes, heart disease, and organ damage. There is no cure, but symptoms can be managed. |
| Alveoli | Tiny air sacs in the lungs that allow the exchange of oxygen and carbon dioxide betweenn the lungs and blood. |
| American College of Sports Medicine [ACSM] | A professional organization that provides guidelines and research on exercise science and sports medicine. |
| Anabolic Steroids | Synthetic substances that mimic testosterone, promoting muscle growth and performance. They can cause hormonal imbalances, liver damage, and cardiovascular issues and are illegal without a prescription. |
| Anaerobically | Refers to activities that occur without oxygen, like weightlifting or sprinting, relying on stored energy sources and producing lactic acid. |
| Android Shape | A fat distribution pattern where fat is stored mainly in the abdomen and upper body. It is linked to a higher waist-to-hip ratio and a greater risk of heart disease, diabetes, and metabolic syndrome due to excess visceral fat. |
| Anger | An emotional response to perceived threats, frustration, or injustice, often involving physiological changes and the urge to take action. |
| Angina | Also known as angina pectoris, is chest pain or discomfort that occurs when part of your heart muscle does not get enough oxygen-rich blood. |
| Angiogram | A coronary angiogram is a test that uses X-rays to look at the heart's blood vessels, called the coronary arteries. |
| Anhedonia | The inability to experience pleasure or interest in once enjoyable activities. |
| Animal-based protein | Protein that comes from foods such as meat, poultry, fish, eggs, and dairy products. These proteins are considered “complete” because they contain all nine essential amino acids the body needs. |
| Annulus Fibrosus | The tough outer layer of an intervertebral disc that surrounds the nucleus pulposus and provides structural integrity. |
| Anorexia Nervosa | An eating disorder marked by extreme food restriction, fear of gaining weight, and a distorted body image, resulting in dangerously low body weight. |
| Antagonist | A muscle that opposes the action of the agonist. |
| Anti-Inflammation Diet | A way of eating that focuses on consuming foods that reduce inflammation in the body. It emphasizes fruits, vegetables, whole grains, healthy fats (like olive oil and nuts), and lean proteins while limiting processed foods, added sugars, and unhealthy fats. |
| Antioxidants | Compounds that protect the body’s cells from damage caused by free radicals, which can contribute to aging and disease. Common dietary antioxidants include vitamins C and E, beta-carotene, and selenium. |
| Anus | The terminal opening through which feces are expelled from the body. |
| Anxiety | A feeling of unease, worry, or apprehension about a potential future threat or uncertain outcome. |
| Anxiety Disorders | Mental health disorders characterized by excessive fear, worry, or nervousness that interfere with daily functioning. |
| Aorta | The body's largest artery; receives blood from the left ventricle and distributes it to the body. |
| Aortic Valve | The heart valve between the left ventricle and the aorta that prevents the back flow of blood into the left ventricle. |
| Appetite Suppressants | Reduce hunger and cravings, aiding weight management by affecting hormones, digestion, or neurotransmitters. |
| Arachnophobia | An intense fear of spiders and other arachnids, causing significant anxiety or avoidance behavior when encountering them. |
| Arrhythmia | An arrhythmia is a heart rhythm that isn't normal. Your heart may be beating too fast when you're at rest or just not beating in a regular pattern. |
| Arrhythmias | A disruption in the normal rhythm of the heart, affecting the rate or pattern of heartbeats. |
| Arteries | Vessels that carry blood away from the heart. |
| Arteriosclerosis | Hardening of the arteries. |
| Arthritis | A condition involving inflammation of the joints, leading to pain, stiffness, and reduced mobility. |
| Articular Cartilage | Smooth cartilage that covers the ends of bones at synovial joints to allow for smooth movement and reduce friction. |
| Articular Surfaces | The surfaces of bones that come into contact at a joint. |
| Asthma | A chronic respiratory condition where the airways become inflamed and narrowed, causing difficulty breathing, wheezing, coughing, and shortness of breath. Symptoms can be triggered by allergens, exercise, cold air, or stress. |
| Atherosclerosis | A condition in which fatty deposits, cholesterol, and other substances build up on the inner walls of arteries, forming plaques. This buildup can narrow or block arteries, reducing blood flow and increasing the risk of cardiovascular diseases such as heart attacks and strokes. |
| ATP Molecules | The primary energy carrier in cells, fueling muscle contractions, metabolism, and cellular functions. ATP is regenerated through aerobic and anaerobic pathways, supporting physical activity and biological processes. |
| Atrium | One of the two upper chambers of the hear in which blood collects before passing to the ventricles. |
| Atrophy | The loss of muscle or tissue mass due to disuse, aging, injury, or disease. It occurs when muscle fibers shrink, but can be slowed with exercise and nutrition. |
| Attribution Theory | A psychological theory that examines how individuals explain the causes of behavior and events, attributing outcomes to internal factors (like ability or effort) or external factors (like luck or situational influences). |
| Autogenic Inhibition | A reflex relaxation of the muscle in response to high tension, often activated during stretching. |
| Autonomic Nervous System (ANS) | The branch of the PNS that regulates involuntary body functions such as heart rate, digestion, and respiratory rate, operating automatically without conscious control. |
| Avoidance | A defense mechanism where individuals unconsciously evade situations, thoughts, or emotions that cause anxiety or distress, providing temporary relief but often hindering long-term resolution. |
| Axon | The long, cable-like extension of a motor neuron that carries electrical impulses (action potentials) away from the cell body toward muscle fibers. |
| Balance | Ability to maintain control of body position while stationary or in motion. It involves coordination, stability, and strength to prevent falls, enhance performance, and efficiently execute movements in sports and physical activities. |
| Ball-and-Socket Joints | Joints that allow movement in all directions, such as the shoulder and hip. |
| Ballistic Stretching | A type of stretching that uses bouncing or jerking movements to increase range of motion. |
| Bardet-Biedl syndrome | A rare genetic disorder causing vision loss, obesity, extra fingers/toes, kidney issues, and developmental delays. It has no cure, but symptoms can be managed. |
| Bariatric Surgery | A weight-loss procedure that reduces stomach size or alters digestion to help limit food intake and promote weight loss. |
| Basal Metabolic Rate | The amount of energy the body requires at rest to maintain essential life functions such as breathing, circulation, and cell production. It represents the minimum number of calories needed to sustain vital bodily processes while at complete rest. |
| Basal Metabolic Rate (BMR) | - **Bio-Electrical Impedance**: A method for estimating body composition by measuring how easily a low electrical current passes through the body. Since muscle conducts electricity better than fat, the resistance (impedance) helps estimate body fat percentage. |
| Behavioral Treatment | A therapy that helps individuals change unhealthy behaviors by using strategies like goal setting, self-monitoring, and positive reinforcement to improve health and well-being. |
| Benign tumor | A benign tumor is a non-cancerous growth of cells that does not spread to other parts of the body. |
| Beta-Alanine | A non-essential amino acid that boosts carnosine levels, delaying muscle fatigue and enhancing endurance and performance. |
| Beta-Blockers | Medications that reduce physical symptoms of anxiety, such as rapid heart rate and trembling, by blocking the effects of adrenaline on the body. |
| Binge Eating Disorder | An eating disorder characterized by regularly consuming large amounts of food in a short period while feeling a loss of control, often followed by guilt or distress, but without compensatory behaviors like purging. |
| Biological Sex | The physical and genetic characteristics a person is assigned at birth, typically categorized as male or female. |
| Bipolar Disorder | A mood disorder characterized by extreme mood swings, including manic episodes of elevated energy and activity, depressive episodes of sadness and low energy, and sometimes mixed episodes with symptoms of both. |
| Blood Alcohol Concentration (BAC) | The ratio of alcohol to blood in the body, typically measured in grams of alcohol per deciliter (g/dL) of blood. |
| Blood Pressure | The force exerted by blood on the walls of the blood vessels, created by the pumping action of the heart. |
| Blood Vessels | Transport blood, oxygen, and nutrients throughout the body. They include arteries (carry blood away from the heart), veins (return blood to the heart), and capillaries (exchange gases and nutrients). |
| Body Composition | The proportion of fat, muscle, bone, and other tissues in the body. It is a key indicator of overall health and fitness, often measured to assess the ratio of lean mass to body fat. |
| Body Dysmorphic Disorder | A mental health condition where a person becomes excessively preoccupied with perceived flaws or defects in their physical appearance, which are often minor or unnoticeable to others, leading to significant distress and impaired daily functioning. |
| Body Dysmorphic Disorder (BDD) | A mental health condition in which a person becomes excessively preoccupied with perceived flaws or defects in their physical appearance. These flaws are often minor or not noticeable to others, but to the individual, they feel significant and distressing. People with BDD may engage in repetitive behaviors such as mirror-checking, excessive grooming, or seeking reassurance, and the condition can interfere with daily functioning, relationships, and overall quality of life. Treatment often involves cognitive-behavioral therapy (CBT) and, in some cases, medication. |
| Body Image | A person’s perception and feelings about their body size, shape, and composition, which may or may not reflect their actual body composition. |
| Body Positivity | A social movement and mindset that encourages individuals to accept, appreciate, and respect their bodies regardless of size, shape, appearance, or ability. It challenges unrealistic beauty standards promoted by media and culture, and instead emphasizes that all bodies are worthy of dignity, confidence, and care. Body positivity also promotes self-compassion, balanced health behaviors, and the idea that physical appearance should not define a person’s value or self-worth. |
| Bone Marrow | Soft, spongy tissue found inside large bones that produces red blood cells, white blood cells, and platelets. It exists in two forms: *red marrow*, which actively generates blood cells, and *yellow marrow*, which primarily stores fat. It plays a key role in treating blood diseases such as leukemia through bone marrow transplantation. |
| Bran | The outer protective covering of the seed that is rich in fiber, B vitamins, and trace minerals. |
| Branched-Chain Amino Acids (BCAAs) | Support muscle growth, recovery, and energy. They enhance protein synthesis, reduce muscle breakdown, and fight fatigue, making them popular in sports nutrition. |
| Bulimia Nervosa | An eating disorder characterized by cycles of binge eating followed by compensatory behaviors such as vomiting, excessive exercise, or fasting to prevent weight gain, often driven by a fear of gaining weight and a distorted body image. |
| Cachexia | Severe loss of muscle and fat mass due to disease, leading to unhealthy body composition and weakness. |
| Caffeine | Caffeine is a natural stimulant that blocks adenosine, increasing alertness, focus, and energy. |
| Calorie | A unit of energy that measures how much energy food provides when consumed and metabolized. |
| Calories | Units of energy that measure the amount of energy food provides when consumed and the body uses when performing physical activities. They are essential for fueling the body’s functions, including breathing, digestion, and movement. |
| Cancer | A disease in which abnormal cells grow uncontrollably and can invade or spread to other parts of the body, disrupting normal body functions and potentially leading to serious health complications. |
| Capillaries | Very small blood vessels that distribute blood to all parts of the body. |
| Carbohydrate | Macronutrients that serve as the body’s main source of energy, found in foods like grains, fruits, vegetables, and dairy. They include sugars, starches, and fiber, which the body breaks down into glucose for fuel. |
| Carbon Dioxide | A gas produced during the metabolism of carbohydrates, fats, protein, and acids. During exercise, the body manages increased levels of carbon dioxide by breathing faster. Plants use carbon dioxide to capture energy through photosynthesis, but high levels of carbon dioxide are toxic to the body. |
| Carbon Monoxide (CO) | A poisonous gas formed when fuels do not burn completely. Because it is invisible and undetectable without a sensor, it is often referred to as a “silent killer.” |
| Cardiac Muscle | A specialized, involuntary muscle found in the heart, responsible for pumping blood throughout the body. It has striated fibers, like skeletal muscle, but functions autonomously, controlled by the autonomic nervous system and pacemaker cells. It is highly fatigue-resistant and works continuously to maintain circulation. |
| Cardiac Output | The volume of blood pumped by the heart per minute via heart rate and stroke volume. |
| Cardiometabolic | Refers to health risks (like heart disease and type 2 diabetes) linked to excess body fat, especially visceral fat, in body composition. |
| Cardiomyopathy | A group of diseases that affect the structure and function of the myocardium (heart muscle), reducing the heart’s efficiency and often leading to serious cardiovascular complications. |
| Cardiorespiratory endurance | Cardiorespiratory endurance is the ability of the heart, lungs, and circulatory system to efficiently supply oxygen to working muscles during sustained physical activity. It is a key component of fitness that enhances overall stamina, reduces fatigue, and improves aerobic performance. |
| Cardiorespiratory System | The system that circulates blood through the body; consists of the heart, blood vessels and respiratory system. Cardiorespiratory system supports encompasses both cardiovascular and respiratory systems. |
| Cardiovascular Disease | A group of conditions that affect the heart and blood vessels, including heart disease, stroke, and high blood pressure, often caused by blocked or narrowed blood vessels, leading to reduced blood flow and increased risk of heart attack or stroke. |
| Cardiovascular System | The system that circulates blood throughout the body and consists of the heart and blood vessels. |
| Carditis | Inflammation of the heart. |
| Cartilage | A flexible connective tissue found in joints, providing cushioning and reducing friction between bones. |
| Cartilage of a Joint | Refers to the specific cartilage (often articular) within a joint that helps absorb shock and enable smooth movement. |
| Cartilaginous Joints (Amphiarthroses) | Joints connected entirely by cartilage, allowing limited movement. |
| Catastrophizing | A cognitive distortion in which an individual assumes the worst possible outcome will occur, often blowing a situation out of proportion and expecting disaster even when it is unlikely. |
| Central Nervous System (CNS) | The part of the nervous system consisting of the brain and spinal cord, responsible for processing information and controlling most functions of the body and mind. |
| Cerebral Embolism | A blockage in a brain artery caused by a clot or debris that formed elsewhere in the body and traveled to the brain, cutting off blood flow. |
| Cerebral Thrombosis | A blood clot that forms directly within a brain artery, gradually blocking blood flow and potentially causing a stroke. |
| Cerebrovascular Disease (Stroke) | A group of conditions that affect blood flow to the brain, often leading to strokes, brain damage, or other neurological issues, usually caused by blocked or ruptured blood vessels. |
| Cervical | Relating to the neck region of the spine, which includes seven vertebrae. |
| Child Abuse | Any act or failure to act that results in a child’s harm, potential harm, or threat of harm, including physical, emotional, sexual abuse, or neglect. |
| Cholesterol | A waxy, fat-like substance that is both produced by the liver and obtained from certain foods.** ** |
| Chronic | A disease or condition that usually lasts for 3 months or longer and may get worse over time. |
| Chronic Disease Risk Reduction Levels (CDRR) | Nutrient intake targets set to help reduce the risk of diet-related chronic diseases, such as heart disease or type 2 diabetes. They represent the maximum daily intake level for certain nutrients where reducing consumption is expected to lower disease risk. |
| Chronic Sleep Deprivation | Persistent lack of adequate sleep over an extended period, which can negatively affect health, mood, and cognitive function. |
| Chronic Stress | Long-term exposure to stressors that persist over weeks, months, or years, often leading to negative health effects. |
| Chronically High Cortisol Levels | A prolonged state of elevated cortisol in the body, often resulting from ongoing stress, which can negatively affect immune function, metabolism, and mental health. |
| Circadian Rhythm Sleep-Wake Disorders | Sleep disorders caused by misalignment between an individual’s internal clock and the external environment, resulting in disrupted sleep patterns. |
| Circadian Rhythms | Biological processes that follow a roughly 24-hour cycle, regulating sleep-wake patterns, hormone release, body temperature, and other physiological functions. |
| Cirrhosis | A progressive liver condition characterized by scarring of liver tissue that interferes with the liver’s ability to perform essential functions such as detoxifying the blood, producing proteins, and aiding in digestion. |
| Cocaine | A central nervous system stimulant that produces short-term pleasurable effects but can lead to serious mental and physical health problems. |
| Coccygeal | Pertaining to the coccyx or tailbone, the lowest part of the vertebral column. |
| Coccyx | The small, triangular bone at the base of the spine, commonly referred to as the tailbone. |
| Coenzymes | Small, organic molecules that work with enzymes to help speed up chemical reactions in the body. |
| Cofactors | Non-protein substances, often minerals, that assist enzymes in carrying out chemical reactions. They can be either inorganic ions like zinc or magnesium, or organic molecules called coenzymes. |
| Cognitive Behavioral Therapy (CBT) | A structured, short-term form of psychotherapy that focuses on identifying and changing negative thought patterns and behaviors to improve emotional regulation and develop healthier coping strategies. |
| Cognitive Drift | The gradual decline in focus, motivation, or commitment to a goal or behavior over time, often leading individuals to revert to old habits or lose sight of their original intentions. |
| Cognitive Overload | When the brain is given more information or tasks than it can effectively process at one time. |
| Cognitive Strategies | Mental techniques used to organize thinking, solve problems, and improve learning or performance. |
| Cognitive Therapy | A form of psychotherapy that helps individuals identify, challenge, and modify unhelpful or distorted thought patterns that contribute to emotional distress and dysfunctional behavior. |
| Cohen syndrome | A rare genetic disorder causing developmental delays, vision problems, low muscle tone, distinct facial features, childhood obesity, and low white blood cell count. Symptoms are managed with supportive care. |
| Collagen | The main protein found in the body’s connective tissues, giving strength, structure, and flexibility to the skin, bones, tendons, ligaments, and cartilage. |
| Community Violence | A type of violence that happens outside the home and typically involves unrelated individuals who may or may not know each other, often occurring in settings like streets, parks, or schools. |
| Complementary protein pairing | The practice of combining two or more plant-based protein sources to provide all nine essential amino acids. For example, eating rice with beans creates a complete protein. |
| Complete proteins | Protein sources that contain all nine essential amino acids in sufficient amounts for the body’s needs. They are typically found in animal products like meat, fish, eggs, and dairy, as well as some plant sources such as quinoa and soy. |
| Complex carbohydrates | Long chains of sugar molecules (starches and fibers) found in foods like whole grains, legumes, and vegetables. They provide sustained energy and often contain fiber, which supports digestion and overall health. |
| Concentric Contraction | When a muscle shortens while generating force, as in lifting a weight. It builds strength, power, and muscle growth in resistance training. |
| Condyloid Joints | Joints that allow movement in two planes without rotation, such as the wrist joint. |
| Conjugated Linoleic Acid (CLA) | An omega-6 fatty acid found in meat and dairy, often used for fat loss, muscle retention, and metabolic support. It may aid body composition and has anti-inflammatory properties. |
| Connective tissue | A type of tissue that supports, connects, or separates parts of the body. It includes ligaments, tendons, cartilage, bone, fat, and blood, and provides structure, protection, and flexibility through proteins like collagen and elastin. |
| Conscientiousness | A personality trait reflecting organization, responsibility, reliability, and goal-directed behavior. |
| Consciousness Raising | The process of increasing awareness and understanding of a behavior or issue to help individuals recognize its impact and motivate change. |
| Contingency Management | A structured behavioral intervention in which individuals receive rewards or incentives (such as vouchers, privileges, or prizes) for meeting specific behavioral goals, such as attending therapy sessions, submitting negative drug tests, or adhering to medication regimens. |
| Contraindicated stretches | Stretching exercises that are considered unsafe or potentially harmful, especially when performed incorrectly or by individuals with certain limitations. These stretches may place excessive stress on joints, muscles, or ligaments and increase the risk of injury. |
| Coordination | Ability to efficiently and smoothly integrate multiple body movements to perform tasks with precision and control. It involves the synchronization of muscles, senses, and motor skills to enhance performance in sports and physical activities. |
| Coping Mechanisms | Strategies or behaviors individuals use to manage stress, emotions, or challenging situations, which can be healthy (e.g., problem-solving, relaxation techniques) or unhealthy (e.g., avoidance, substance use). |
| Coronary arteries | A pair of large blood vessels that branch off the aorta and supply the heart muscle with oxygenated blood. |
| Coronary Artery Disease | A disease in which there is a narrowing or blockage of the coronary arteries (blood vessels that carry blood and oxygen to the heart). Coronary artery disease is usually caused by atherosclerosis (a buildup of fatty material and plaque inside the coronary arteries). |
| Corticosteroids | Medications that can alter body composition by increasing fat mass (especially visceral fat) and reducing muscle mass when used long-term. |
| Cortisol | A stress hormone that can influence body composition by promoting fat storage, especially visceral fat, and breaking down muscle when chronically elevated. |
| Counter Conditioning | The process of replacing unhealthy behaviors or thoughts with healthier alternatives. It involves choosing positive responses to triggers or situations that previously led to negative habits. |
| CRAP | An acronym that stands for "calorie-rich and processed foods" and/or "carbonated drinks, refined sugars, artificial additives, and processed foods." |
| Creatine | A natural compound in muscles that helps regenerate ATP, boosting strength, power, and recovery. Commonly supplemented as creatine monohydrate, it enhances performance and muscle growth. |
| Creatine Phosphate | A molecule that is sotred in muscle cells and used in the immediate energy system to donate a phosphate to make ATP. |
| Cross-Contamination | The transfer of harmful bacteria from one surface or food to another, often occurring when raw and ready-to-eat foods come into contact without proper cleaning, leading to potential foodborne illness. |
| Cross-Education | When training one limb increases strength in the untrained limb due to neural adaptations. It aids injury recovery, neuromuscular efficiency, and rehabilitation. |
| Cultural Wellness | The ability to respect, understand, and engage with different cultural values, beliefs, and traditions, fostering inclusivity, mutual respect, and a sense of belonging in diverse environments. |
| Curable | (of a disease or condition) able to be cured. |
| Cushing’s syndrome | Caused by excess cortisol, often from steroid use or a tumor. Symptoms include weight gain, a round face, thin skin, muscle weakness, and high blood pressure. Treatment targets the underlying cause. |
| Daily Hassles | Minor, everyday irritations or challenges, such as traffic, deadlines, or household chores, that can accumulate and contribute to stress over time. |
| Daily Values (DVs) | reference amounts of nutrients set by the FDA to help consumers understand the nutrient content of foods in the context of a total daily diet. They are used on Nutrition Facts labels as percentages based on a 2,000-calorie diet. |
| Defense Mechanisms | A subconscious psychological strategy used by individuals to protect themselves from anxiety, stress, or uncomfortable emotions, often by distorting or avoiding reality. |
| Degenerative Disc Disease | A condition where intervertebral discs lose flexibility and cushioning, often causing pain. |
| Dehydration | A condition that occurs when the body loses more fluids than it takes in, leading to an insufficient amount of water to maintain normal bodily functions. It can cause symptoms such as fatigue, dizziness, dry mouth, and impaired physical and cognitive performance, especially during exercise or in hot conditions. |
| Delusions | Strongly held false beliefs that persist despite evidence to the contrary, often seen in schizophrenia and other psychotic disorders. |
| Dementia | A group of disorders characterized by a decline in memory, thinking, behavior, and the ability to perform everyday activities, often caused by damage to brain cells. |
| Denial | A psychological defense mechanism in which a person refuses to acknowledge or accept the reality of a situation, problem, or feeling, often to avoid discomfort, anxiety, or emotional pain. |
| Department of Health and Human Services (DHHS) | A U.S. federal agency responsible for protecting public health and providing essential human services. It oversees agencies such as the FDA, CDC, and NIH. |
| Depressants | Substances that reduce arousal and stimulation in the central nervous system. |
| Depression | A mental health disorder characterized by persistent feelings of sadness, hopelessness, and loss of interest or pleasure in activities, often accompanied by physical symptoms such as fatigue, changes in appetite, and difficulty concentrating. |
| Detoxification | A medically supervised process that helps individuals safely eliminate addictive substances from the body while managing the physical and psychological effects of withdrawal. |
| Detraining | The gradual loss of fitness and physiological adaptations that occur when an individual reduces or stops regular exercise. This can lead to declines in cardiovascular endurance, muscle strength, flexibility, and overall performance, depending on the duration and extent of inactivity. |
| Diabetes | A chronic condition where the body cannot properly regulate blood sugar (glucose) levels due to problems with insulin production or function, leading to high blood sugar and potential long-term health complications. |
| Diastole | The period of the heart’s relaxation. |
| Diet | The types and amounts of food and beverages a person habitually consumes to meet their nutritional needs and maintain overall health. |
| Dietary Approaches to Stop Hypertension (DASH) Diet | An eating plan designed to lower high blood pressure by emphasizing fruits, vegetables, whole grains, lean proteins, and low-fat dairy while reducing sodium, saturated fats, and added sugars. |
| Dietary cholesterol | Cholesterol found in animal-based foods such as meat, eggs, and dairy products. While it can raise blood cholesterol levels in some people, its effect is generally less significant than that of saturated and trans fats. |
| Dietary fiber | This refers specifically to the indigestible parts of plant foods—such as fruits, vegetables, grains, and legumes—that help regulate the body’s use of sugars, assist in digestion, and contribute to satiety and bowel regularity. |
| Dietary Folate Equivalents (DFE) | A unit used to account for the differences in bioavailability (how well the body absorbs and uses) between natural folate from food and synthetic folic acid from supplements or fortified foods. |
| Dietary Guidelines | Science-based recommendations that provide advice on healthy eating patterns to promote health, reduce the risk of chronic diseases, and meet nutritional needs. |
| Dietary Guidelines Advisory Committee (DGAC) | A group of experts appointed by the U.S. Departments of Agriculture (USDA) and Health and Human Services (HHS) to review nutrition science. Their recommendations help shape the Dietary Guidelines for Americans, updated every five years. |
| Dietary Guidelines for Americans (DGAs) | Science-based recommendations published every five years by the USDA and HHS. They provide advice on healthy eating patterns to promote health, reduce the risk of chronic disease, and meet nutrient needs. |
| Dietary pattern | The overall combination of foods and beverages a person regularly consumes. It emphasizes how different foods and nutrients work together to affect health over time. |
| Dietary Reference Intakes (DRIs) | A set of standards that includes recommended intakes of all essential nutrients, recommendations for balancing intakes of macronutrients, and upper safe limits for selected nutrients. |
| Dietary Thermogenesis (Thermic Effect of Food) | The increase in energy expenditure that occurs after eating, as the body digests, absorbs, transports, and stores nutrients. It typically accounts for about 5–10% of total daily energy expenditure. |
| Diffusion | The process by which oxygen moves from the lungs to the blood and carbon dioxide moves from the blood to the lungs; faster breathing concentrates oxygen and decreases carbon dioxide in the lungs and promotes diffusion. |
| Diffusion Capacity | The amount of oxygen that enters the blood stream from the lungs. |
| Digestion | The process by which the body breaks down food into smaller components, such as nutrients, that can be absorbed and used for energy, growth, and repair. It involves both mechanical actions, like chewing, and chemical processes, such as enzyme activity. |
| Digital Wellness | Maintaining a healthy relationship with technology and digital media. It involves using devices, apps, and online platforms in a way that supports your mental, physical, and emotional well-being—rather than disrupting it. |
| Disaccharides | are carbohydrates made up of two monosaccharide molecules bonded together; common examples include sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (glucose + glucose). |
| Disordered Fear | Fear that is excessive, persistent, or maladaptive, interfering with normal daily functioning. |
| Displacement | A defense mechanism where emotions, like anger, are unconsciously redirected from their original source to a safer, less threatening target. |
| Distress | A negative form of stress that occurs when demands exceed coping abilities, potentially leading to physical, emotional, or behavioral health problems. |
| Dramatic Relief | The process of experiencing and expressing strong emotions—like fear, sadness, or hope—in response to learning about a behavior’s impact. |
| Drug Overdose | A toxic and dangerous reaction to a substance (or substances) that overwhelms the body’s normal functioning, often leading to serious health complications or death if not treated promptly. |
| Dual Energy X-Ray Absorptiometry | A medical imaging technique that uses low-dose X-rays to measure bone density and body composition, including the amount of fat, muscle, and bone in the body. |
| Duration | The length of time a muscle contraction or exercise bout is sustained, influencing energy system use and fatigue development. |
| Dynamic Constant Training (DCT) | Lifting a constant load throughout a movement, as seen in free weights and machines. It improves strength, muscle mass, and coordination, making it effective for all fitness levels. |
| Dynamic Contraction | A muscle contraction with movement, including concentric (shortening) and eccentric (lengthening) actions. It enhances strength, power, and muscle control in resistance training. |
| Dynamic Flexibility | The ability to move joints through their full range of motion during active movements. |
| Dynamic Progressive Training (DPT) | Gradually increases resistance, weight, or reps to promote strength, muscle growth, and endurance. It follows progressive overload, preventing plateaus and ensuring continuous improvement. |
| Dynamic Stretching | A form of stretching involving movement to increase flexibility and warm up muscles. |
| Dynamic Variable Training (DVT) | Adjusts resistance throughout a movement using bands, chains, or machines to match strength curves. It enhances strength, muscle activation, and power, reducing sticking points in lifts. |
| Dypsnea | commonly known as shortness of breath, is the subjective sensation of uncomfortable breathing, often described as difficult or labored breathing. |
| Dysfunctional Attitudes | Negative, rigid, and often unrealistic thought patterns that can distort perception, hinder emotional well-being, and interfere with healthy behavior and decision-making. |
| Dystrophy | The degeneration or weakening of tissue, often due to genetic, metabolic, or nutritional disorders. |
| E-Cigarettes | Electronic nicotine delivery systems (ENDS) designed to simulate smoking by producing a vapor or aerosol instead of smoke. |
| Eating Disorders | Mental health conditions characterized by unhealthy and harmful eating behaviors, such as extreme food restriction, binge eating, or purging, often driven by concerns about body image, weight, or control. |
| Eccentric Contraction | When a muscle lengthens under tension, controlling movement and absorbing force. Examples include lowering a weight or descending in a squat. They enhance strength, muscle growth, and injury prevention. |
| Emotional Health | The ability to recognize, understand, and manage one’s emotions in healthy and constructive ways, including expressing feelings appropriately, coping with challenges, and maintaining balance during positive and stressful times. |
| Emotional Wellness | The ability to understand, manage, and express emotions effectively, while maintaining resilience, coping with challenges, and fostering positive relationships. |
| Empty Calories | calories from foods and beverages that provide little to no nutritional value—meaning they are high in added sugars and/or solid fats but low in essential nutrients like vitamins, minerals, or fiber. Common sources include sugary drinks, candy, pastries, and fried foods. |
| Endemic | Endemic means a disease that is always present in a population within a geographic area, typically year-round. |
| Endometriosis | A disorder in which tissue similar to the lining of the uterus grows outside the uterus, often causing pelvic pain. |
| Endomysium | A thin connective tissue layer that surrounds individual muscle fibers within a fascicle. It provides structural support, facilitates nutrient and oxygen exchange, and helps transmit force during muscle contractions. |
| Endosperm | The Large center of the seed that provides energy, primarily in the form of complex carbohydrates. |
| Endothelial Cells | Cells lining the blood vessels. |
| Energy Balance | The relationship between calories consumed (energy intake) and calories expended (energy output through metabolism, physical activity, and thermic effect of food). |
| Energy Expenditure | The total amount of energy (calories) the body uses to sustain life and support physical activity. Energy expenditure includes basal metabolic rate (BMR), the thermic effect of food (TEF), and energy used during physical activity. |
| Energy Intake | The total number of calories consumed from food and beverages. Energy intake provides the fuel needed for basal metabolism, physical activity, and physiological functions. |
| Energy-dense | Foods that provide a high amount of calories relative to their weight or volume. They are often high in fat and added sugars but low in nutrients, such as fast food, pastries, and fried snacks. |
| Environmental Reevaluation | The process of recognizing how one’s behavior affects others and the environment. It involves understanding the social and environmental consequences of actions, which can motivate change out of concern for others or the greater good. |
| Environmental Stressors | External conditions or situations in a person’s surroundings that cause stress, such as noise, pollution, extreme weather, overcrowding, or unsafe living conditions. |
| Environmental Wellness | Maintaining a healthy and sustainable relationship with the natural and built environment, including taking actions to protect and preserve the planet while creating safe, supportive, and clean surroundings. |
| Epidemic | An unexpected increase in the number of disease cases in a specific geographical area. |
| Epimysium | The outermost connective tissue layer that surrounds an entire skeletal muscle, providing structural support and protection. |
| Ergonomics | The study and design of work environments to promote efficiency and reduce strain on the body. |
| Esophagus | A muscular tube that transports food from the pharynx to the stomach. |
| Essential Fat | The minimum amount of fat needed for normal body function, including hormone production, nerve function, and protecting organs; part of healthy body composition. |
| Etiology | The cause or origin of a disease or condition. |
| Eustress | A positive form of stress that enhances motivation, focus, and performance, often associated with growth and achievement. |
| Exercise-Associated Hyponatremia | A condition occurring during or after prolonged physical activity in which blood sodium levels drop below 135 mEq/L, typically due to excessive fluid intake outpacing sodium losses. |
| Exercise: | A planned, structured, and repetitive physical activity performed to improve or maintain physical fitness, health, and overall well-being. It can include activities that enhance cardiovascular endurance, muscular strength, flexibility, and coordination. |
| Exposure Therapy | A therapeutic technique in which individuals gradually confront feared objects, situations, or memories in a controlled and safe manner to reduce anxiety and avoidance behaviors. |
| External Lamina | The external lamina is a thin layer of connective tissue surrounding individual muscle fibers. It is composed primarily of collagen and glycoproteins and provides structural support, protection, and a scaffold for muscle regeneration by facilitating satellite cell activity. |
| Extraversion | A personality trait characterized by sociability, assertiveness, and positive emotionality. |
| Fascicles | Bundles of muscle fibers grouped together within a skeletal muscle, surrounded by perimysium. They contribute to muscle strength, flexibility, and function, with their arrangement affecting force production and movement efficiency. |
| Fasciculus | A bundle of muscle fibers surrounded by perimysium, a connective tissue layer. |
| Fast-Twitch Muscle Fibers | Muscle fibers that generate quick, powerful movements but fatigue rapidly; in body composition, they contribute to lean mass and athletic performance. |
| Fat (triglycerides) | The most common type of fat in the body and food, consisting of three fatty acids attached to a glycerol backbone. They serve as a major energy source and are stored in adipose tissue for later use. |
| Fat Blockers | Supplements that inhibit fat absorption by blocking lipase enzymes, reducing calorie intake. |
| Fat Distribution Patterns | The way body fat is stored in the body, such as android (apple-shaped, around the abdomen) or gynoid (pear-shaped, around hips and thighs), which influences health risks and overall body composition. |
| Fat Mass (FM) | The total amount of fat tissue in the body, including both essential fat needed for normal body functions and non-essential fat stored for energy. |
| Fat-Free Mass (FFM) | The total weight of all body components excluding fat, including muscles, bones, organs, fluids, and tissues. |
| Fat-soluble vitamins | Vitamins (A, D, E, and K) that dissolve in fat and are stored in the body’s fatty tissue and liver. Because they can accumulate, excessive intake may lead to toxicity. |
| Fatty acids | The building blocks of fats, made up of chains of carbon and hydrogen atoms with a carboxyl group at one end. They can be classified as saturated, monounsaturated, or polyunsaturated, depending on their chemical structure. |
| Faulty Conceptualization | The inaccurate or mistaken interpretation of a situation, symptom, or problem, often leading individuals to downplay or misattribute serious issues—such as viewing early signs of illness as harmless—thereby delaying appropriate action or change. |
| Fear | An emotional response to an immediate, real, or perceived threat that prepares the body for action. |
| Female Athlete Triad | A medical condition involving three interrelated components: low energy availability (with or without disordered eating), menstrual dysfunction, and low bone mineral density. It is commonly seen in physically active females and can lead to serious long-term health issues if not properly addressed. |
| Fentanyl | A synthetic opioid analgesic that is 50 to 100 times more potent than morphine. |
| Fiber | A type of carbohydrate that the body cannot digest or absorb. It passes through the digestive system largely intact and plays a vital role in maintaining digestive health. |
| Fiber Recruitment | The process by which the nervous system activates muscle fibers to generate force. Efficient fiber recruitment enhances strength, power, and endurance, and is improved through progressive overload and neuromuscular training. |
| Fiber Supplements | Products designed to increase dietary fiber intake, aiding in digestion, gut health, and regularity. Commonly used for constipation relief, blood sugar control, and weight management. |
| Fibromyalgia | A chronic condition characterized by widespread musculoskeletal pain, fatigue, and tender points. |
| Fibrous Joints (Synarthroses) | Joints connected by dense connective tissue, allowing little or no movement. |
| Fight-or-Flight Response | The body’s automatic physiological reaction to a perceived threat, preparing an individual to either confront or escape danger. It involves increased heart rate, rapid breathing, heightened alertness, and the release of stress hormones such as adrenaline. |
| Financial Wellness | The ability to effectively manage your financial resources, meet current and future financial obligations, and feel secure and confident about your financial stability. |
| Firearm Violence | The threatened or actual use of a gun to cause harm, intimidate, or exert power over others. |
| FITT Principle | Guides exercise programming with four key factors: frequency, intensity, time, and type. |
| FITT-VP Principle | Guides exercise programming with six key factors: Frequency (how often), Intensity (effort level), Time (duration), Type (exercise mode), Volume (total workload), and Progression (gradual increase for improvement). |
| Five-Factor Model | A widely accepted framework for describing personality using five dimensions: openness, conscientiousness, extraversion, agreeableness, and neuroticism. |
| Fixators | Stabilizing muscles that prevent unwanted movement, providing a stable base for prime movers. They aid in balance, posture, and injury prevention. |
| Flat Affect | A severe reduction or absence of emotional expression, often observed in schizophrenia and other mental health disorders. |
| Flavonoids | A group of naturally occurring plant compounds with antioxidant and anti-inflammatory properties. They are found in foods like fruits, vegetables, tea, and dark chocolate, and may help protect against chronic diseases. |
| Flexibility | The ability of a joint or group of joints to move through their full range of motion (ROM) without pain, discomfort, or restriction. It depends on the length and elasticity of muscles, tendons, and ligaments, as well as joint structure and nervous system function. Flexibility is essential for efficient movement, injury prevention, and overall physical function. |
| FOMO (Fear of Missing Out) | Anxiety or worry that others are having rewarding experiences without you, often fueled by social media or comparisons, which can increase stress and reduce life satisfaction. |
| Food and Drug Administration (FDA) | A U.S. federal agency responsible for protecting public health by regulating food, drugs, medical devices, and dietary supplements. It ensures the safety, effectiveness, and accurate labeling of these products. |
| Force | The amount of tension produced by a muscle during contraction; it depends on motor unit recruitment, firing rate, and muscle cross-sectional area. |
| Free radicals | Unstable molecules with unpaired electrons that can damage cells, proteins, and DNA through oxidative stress. They are produced naturally in the body and can also come from external sources like pollution, smoking, and radiation. |
| Frequency | Frequency refers to how often a muscle group or exercise is trained within a given period, typically measured in workouts per week. Frequency should be balanced with intensity, volume, and recovery to maximize strength gains while preventing over-training. |
| Frost bite | Cold-related injury that occurs when skin and underlying tissues freeze due to prolonged exposure to extreme cold temperatures. It commonly affects extremities such as fingers, toes, ears, and the nose, leading to numbness, discoloration, and potential tissue damage. |
| Frost-nip | A mild form of frostbite that occurs when the skin is exposed to cold temperatures, causing temporary numbness and redness without permanent tissue damage. It typically affects extremities like fingers, toes, ears, and the nose, and can be reversed by gradually warming the affected area. |
| FTO Gene | A gene linked to body composition that can increase the likelihood of higher body fat levels and obesity by influencing appetite and energy balance. |
| Gallbladder | A small, green organ beneath the liver that stores and releases bile into the small intestine. |
| Gallbladder Disease | Conditions that affect the gallbladder, such as gallstones, inflammation (cholecystitis), or infection, often cause pain, digestive issues, and in some cases, require surgical removal of the gallbladder. |
| Gender Dysphoria | Psychological distress resulting from a mismatch between an individual’s gender identity and their assigned sex at birth. |
| Gender Identity | A person’s deeply held internal sense of their own gender, which may be male, female, a blend of both, neither, or something else entirely. It is how individuals perceive themselves and what they call themselves, which may or may not align with the sex assigned to them at birth. |
| Gene-Environment Interaction | How genetic factors (like those affecting fat storage or muscle growth) and lifestyle factors (such as diet, physical activity, and stress) work together to shape body composition. |
| General Adaptation Syndrome (GAS) | A model describing the body’s three-stage response to prolonged stress: alarm, resistance, and exhaustion. |
| Generalized Anxiety Disorder (GAD) | A mental health condition characterized by excessive, persistent worry and fear about various aspects of daily life, often accompanied by symptoms like restlessness, fatigue, difficulty concentrating, irritability, muscle tension, and sleep disturbances. |
| Germ | A part of the plant seed from which a new plant can sprout that provides fatty acids, vitamin E, B vitamins, and antioxidants. |
| Ghrelin | A hormone that increases hunger and food intake; it influences body composition by promoting fat storage when energy intake exceeds energy use. |
| Glucose | A simple sugar that serves as the body’s primary source of energy for cells, tissues, and organs. It is obtained from carbohydrates in food and transported in the blood as blood sugar. |
| Gluten Free | A diet or food product that does not contain gluten, a protein found in wheat, barley, and rye, commonly followed by individuals with celiac disease or gluten sensitivity. |
| Glycemic index (GI) | A measure of how quickly a carbohydrate-containing food raises blood glucose levels compared to pure glucose. Foods with a high GI cause rapid spikes in blood sugar, while low-GI foods lead to slower, steadier increases. |
| Glycogen | A stored form of glucose found primarily in the liver and muscles, serving as a key energy reserve for the body. Glycogen is replenished through carbohydrate consumption after depletion. |
| Golgi Tendon Organs (GTOs) | Sensory receptors in tendons that detect changes in muscle tension and help prevent injury. |
| Goniometers | Instruments used to measure the range of motion in a joint. |
| Gout | A type of arthritis caused by the buildup of uric acid crystals in the joints, leading to sudden episodes of severe pain, swelling, redness, and stiffness, most often in the big toe. |
| Green Tea Extract | A concentrated form of bioactive compounds from green tea leaves, rich in antioxidants, especially catechins like EGCG (epigallocatechin gallate). It is known for its benefits in metabolism, fat oxidation, heart health, and cognitive function. |
| Gynoid Shape | A fat distribution pattern where more fat is stored in the hips and thighs; in body composition, it’s generally linked to lower health risks than abdominal (android) fat storage. |
| Hallucinations | Perceptions of sights, sounds, or sensations that are not present in reality, commonly associated with psychotic disorders. |
| Hallucinogens | Substances that profoundly alter a person’s sensory perception, emotional state, and consciousness, often causing visual or auditory hallucinations, distorted sense of time, and altered thinking or reality. |
| Heart Rate | The number of times your heart beats per minute (bpm). |
| Heart Rate Reserve | The difference between maximum heart rate and resting heart rate; used in one method for calculating target heart rate zone. |
| Heat cramps | Painful, involuntary muscle spasms that occur due to excessive loss of fluids and electrolytes through sweating, often during intense physical activity in hot conditions. They are an early sign of heat-related illness and can be relieved by rehydration and rest. |
| Heat exhaustion | A heat-related illness caused by prolonged exposure to high temperatures and inadequate fluid intake, leading to symptoms such as heavy sweating, dizziness, nausea, weakness, and rapid pulse. If untreated, it can progress to heat stroke, a life-threatening condition. |
| Heat stroke | Heat stroke is a severe, life-threatening heat-related illness that occurs when the body’s temperature regulation system fails, causing core body temperature to rise above 104°F (40°C). Symptoms include confusion, loss of consciousness, rapid heartbeat, and hot, dry skin, requiring immediate medical attention to prevent organ damage or death. |
| Helping Relationships | Supportive connections with others that encourage and assist in behavior change. These relationships provide emotional support, accountability, and motivation, often through friends, family, mentors, or support groups. |
| Hemorrhagic | Relating to or involving bleeding; in the stroke context, it refers to a stroke caused by a ruptured blood vessel leaking blood into or around the brain. |
| Herniated or Ruptured Discs | A condition where the inner nucleus pulposus protrudes through the outer annulus fibrosus, potentially compressing spinal nerves. |
| Heroin | A powerful, illegal opioid that rapidly affects the brain, producing intense feelings of euphoria and pain relief, but also leading to tolerance, dependence, and addiction. |
| High Intensity Interval Training (HIIT) | A workout style alternating short bursts of intense exercise with recovery periods; it improves body composition by reducing fat mass and preserving or increasing lean muscle. |
| High-density lipoprotein (HDL) cholesterol | Often called “good” cholesterol because it helps remove excess cholesterol from the bloodstream and transports it to the liver for excretion. Higher HDL levels are linked to a lower risk of heart disease. |
| High-Density Lipoproteins (HDL) | It is sometimes called the "good" cholesterol because it carries cholesterol from other parts of your body back to your liver. Your liver then removes the cholesterol from your body. |
| High-Intensity Interval Training (HIIT) | A training technique that involves short bursts of intense exercise alternated with periods of low-intensity recovery. |
| Hinge Joint | A joint that permits movement in one direction, such as the elbow or knee. |
| Holistic approach to healthy eating | This approach considers not only the nutritional content of food but also how dietary choices impact overall well-being, including physical, mental, social, and environmental health. This approach emphasizes balance, variety, and moderation, while also taking into account factors like cultural preferences, food sourcing, lifestyle habits, and the enjoyment of food as part of a healthy, sustainable lifestyle. |
| Homeostasis | The process by which an organism automatically regulates its internal conditions (such as temperature, pH, and chemical balance) to maintain stability despite changes in the external environment. |
| Homeostatic Sleep | The body’s natural process of regulating sleep intensity and duration based on prior wakefulness, ensuring balance between sleep and wakefulness. |
| Hydrostatic Weighing | A method of measuring body composition by determining body density through underwater weighing, where a person’s weight on land and underwater are compared to estimate body fat percentage. |
| Hyperglycemia | A term for high blood glucose (blood sugar). |
| Hypermobility | A condition where joints move beyond the normal range of motion, often due to genetic factors. |
| Hypertension | A condition characterized by consistently high blood pressure, which forces the heart to work harder to pump blood and increases the risk of heart disease, stroke, kidney problems, and other health issues. |
| Hypervitaminosis | A condition that occurs when a person has excessive levels of one or more vitamins in the body, typically as a result of over-supplementation rather than food intake. This buildup can lead to toxic effects and interfere with normal body functions. |
| Hypoglycemia | Abnormally low blood sugar levels, which can cause symptoms resembling a stroke (confusion, weakness, dizziness) but are reversible with glucose restoration. |
| Hypogonadism | A medical condition characterized by reduced production of sex hormones (such as testosterone in males or estrogen in females). |
| Hyponatremia | A medical condition characterized by abnormally low sodium concentration in the blood, typically resulting from excessive fluid intake, excessive sodium loss (such as through prolonged sweating), or a combination of both. In exercise settings, it most often occurs when an individual consumes large amounts of fluid without adequate electrolyte replacement, leading to dilution of blood sodium levels and potential impairment of nerve, muscle, and brain function. |
| Hypothalamic-Pituitary-Adrenal (HPA) Axis | A complex system involving the hypothalamus, pituitary gland, and adrenal glands that controls the body’s stress response and regulates cortisol production. |
| Hypothermia | A dangerous condition that occurs when the body loses heat faster than it can produce it, causing core body temperature to drop below 95°F (35°C). Symptoms include shivering, confusion, slowed heart rate, and loss of coordination, and if untreated, it can lead to unconsciousness and death. |
| Hypothyroidism | A condition where the thyroid makes too much hormone, causing weight loss, fast heartbeat, nervousness, and heat intolerance. It’s treated with medication, radioactive iodine, or surgery. |
| Immediate (“Explosive") Energy System | The system that supplies very short bursts of energy to muscle cells through the breakdown of cellular stores of ATP and creatine phosphate (CP). |
| Immunosuppressant | Any substance or factor that reduces or inhibits the effectiveness of the immune system, often increasing susceptibility to infections or disease. |
| Inactivity-Mobility Cycle | is a self-reinforcing pattern in which reduced physical activity leads to decreased joint mobility and flexibility, which in turn makes movement more difficult and uncomfortable. As mobility declines, individuals tend to become even less active, further worsening mobility. This cycle can contribute to muscle stiffness, joint pain, and a decline in overall physical function and quality of life. |
| Inclinometers | Devices used to measure the angle of joint movement or spinal curvature. |
| Incomplete proteins | Protein sources that lack one or more of the nine essential amino acids. They are typically found in plant-based foods such as grains, nuts, seeds, and vegetables. |
| Individual Differences, Principle of | The concept that flexibility programs should be tailored to an individual's unique body structure, capabilities, and needs. |
| Infectious Agent | A microbe or pathogen that can invade a host and cause disease. |
| Insertion | The movable attachment of a muscle, where force is applied to create movement. It is typically distal to the origin and moves toward it during contraction. |
| Insoluble fiber | A type of dietary fiber that does not dissolve in water and adds bulk to stool, helping prevent constipation. It is found in foods like whole grains, nuts, seeds, and the skins of fruits and vegetables. |
| Insomnia | A sleep disorder characterized by difficulty falling asleep, staying asleep, or obtaining restorative sleep, despite adequate opportunity. |
| Instrumental Activities of Daily Living (IADLs) | Are more complex tasks that enable individuals to live independently in a community. They go beyond basic self-care (ADLs) and involve activities like managing finances, transportation, and meal preparation. |
| Intellectual Wellness | Actively engaging in lifelong learning, critical thinking, creativity, and the pursuit of knowledge to expand skills, challenge the mind, and foster personal growth. |
| Intensity | The level of effort or difficulty at which a physical activity is performed. It is typically categorized as low, moderate, or vigorous and can be measured using heart rate, perceived exertion, or other physiological markers to ensure appropriate workout effectiveness and safety. |
| Intermittent Fasting | An eating pattern that cycles between periods of eating and fasting, focusing on when you eat rather than what you eat, and is often used for weight management and potential health benefits. |
| Intervertebral Discs | Cushion-like pads between the vertebrae that absorb shock and allow movement in the spine. |
| Intimate Partner Violence (IPV) | Physical, sexual, psychological, or emotional abuse, stalking, or economic control by a current or former partner or spouse. |
| Intracerebral Hemorrhage | Bleeding that occurs directly within the brain tissue itself, typically from a ruptured blood vessel, causing rapid pressure buildup and brain damage. |
| Inverse Myotatic Reflex | A protective reflex that causes a muscle to relax when there is excessive tension, often mediated by the Golgi tendon organs. |
| Irrational Anxiety | Persistent worry or apprehension that is disproportionate to the actual likelihood or severity of a threat. |
| Irrational Fear | An excessive or unreasonable fear of a situation or object that poses little or no actual danger. |
| Ischemic | Relating to insufficient blood supply to tissue; an ischemic stroke occurs when a blockage prevents adequate blood flow to part of the brain. |
| Isokinetic Training (IKT) | A type of resistance training where muscle contractions occur at a constant speed throughout the range of motion, regardless of the force applied. |
| Isometric Contraction | A type of muscle contraction where the muscle generates tension without changing length or causing joint movement. It helps build strength, endurance, and stability by maintaining a static position. |
| Isometric Training (IMT) | A resistance training method where muscles generate force without changing length or causing joint movement. It enhances strength, endurance, and stability by maintaining static muscle contractions. |
| Isotonic Contraction | A type of muscle contraction where the muscle changes length while generating constant tension. |
| Isotonic Training | A type of resistance exercise where muscles generate force while changing length, maintaining constant tension throughout the movement. |
| Joint | A location where two or more bones meet, allowing for varying degrees of movement. |
| Joint Capsule | A fibrous tissue envelope that encloses a synovial joint, providing stability while allowing movement. |
| Joint Structure | The anatomical features of a joint, including bones, cartilage, ligaments, and the joint capsule, that influence movement and flexibility. |
| Ketogenic Diet | A high-fat, very low-carbohydrate diet that shifts the body into a state of ketosis, where it burns fat for energy instead of carbohydrates, commonly used for weight loss and managing certain medical conditions. |
| Kidney Disease | A condition where the kidneys are damaged and cannot properly filter waste and excess fluids from the blood, which can lead to fluid buildup, waste accumulation, and other serious health problems. |
| Kilocalorie (kcal) | The amount of energy needed to raise the temperature of 1 kilogram of water by 1°C. In nutrition, it is the standard unit used to measure the energy content of foods, and it is often referred to simply as a “Calorie.” |
| L-Carnitine | Naturally occurring amino acid derivative that plays a crucial role in fat metabolism and energy production. It transports fatty acids into mitochondria, where they are converted into ATP through beta-oxidation. |
| L-Glutamine | Conditionally essential amino acid involved in muscle recovery, immune function, and gut health. It serves as a key fuel source for rapidly dividing cells, including immune and intestinal cells. It also supports protein synthesis, nitrogen balance, and energy production. |
| Lactic Acid | A byproduct of anaerobic metabolism, produced when the body breaks down glucose for energy in low-oxygen conditions, such as intense exercise. |
| Large Intestine (Colon) | Includes ascending, transverse, descending, and sigmoid sections; responsible for water absorption and forming feces. |
| Learned Helplessness | A condition in which repeated exposure to uncontrollable or adverse events leads an individual to believe they have no control over outcomes, often resulting in passive behavior and feelings of resignation. |
| Legumes | A group of plants that include beans, lentils, peas, and chickpeas, valued for their high protein, fiber, and nutrient content. They are an important source of plant-based protein and can help support heart and digestive health. |
| Ligaments | Strong bands of connective tissue that connect bones at joints and provide stability. |
| Linoleic acid (18:2) | An essential omega-6 fatty acid that the body cannot produce and must obtain from food. It is found in vegetable oils, nuts, and seeds, and plays a key role in cell structure and normal growth. |
| Lipids | A group of fats and fat-like substances, including triglycerides, phospholipids, and sterols, that are insoluble in water but essential for energy, cell structure, and hormone production. They provide more than twice the energy per gram compared to carbohydrates or proteins. |
| Lipogenesis | the metabolic process by which the body converts excess carbohydrates and proteins into fatty acids, which are then stored as fat. This primarily occurs in the liver and adipose tissue. |
| Lipoproteins | They are complex particles composed of lipids (fats) and proteins that transport lipids throughout the bloodstream. They play a crucial role in the metabolism and distribution of fats in the body. |
| Liver | A large organ located on the upper right side of the abdomen; it produces bile for fat digestion. |
| Long-Term Stressors | Stressful events or conditions that persist over an extended period, often weeks, months, or even years. They can have ongoing effects on physical and emotional health and may contribute to chronic stress, anxiety, or other mental health concerns. |
| Low Body Composition | Having a low percentage of body fat and a higher proportion of lean mass (muscle, bone, and other fat-free tissues), which is generally associated with better physical fitness and health when maintained within healthy ranges. |
| Low-Density Lipoproteins (LDL) | A type of cholesterol that is often referred to as "bad" cholesterol. It is a lipoprotein, which means it is a combination of fat (cholesterol) and protein |
| Low-Density Lipoprotein Cholesterol (LDL) | Often called “bad” cholesterol because high levels can lead to plaque buildup in arteries, increasing the risk of heart disease and stroke. It carries cholesterol from the liver to the body’s cells. |
| Lumbar | Refers to the lower back region of the spine, consisting of five vertebrae. |
| Lymph Nodes | Bean-shaped structures that filter lymph fluid, trap pathogens, and house immune cells. |
| Lymphocytes | Small white blood cells critical for immune defense. |
| Macronutrients | Nutrients the body needs in large amounts to provide energy and support basic functions: carbohydrates, proteins, and fats. Water is also considered a macronutrient, though it does not provide calories. |
| Macrosomia | A condition where a baby is born significantly larger than average, a risk that maternal physical activity during pregnancy can help reduce. |
| Maladaptive Coping Strategies | Unhealthy or ineffective methods of managing stress, emotions, or challenges, such as substance use, avoidance, or denial, which may provide temporary relief but worsen long-term mental health. |
| Male Athlete Triad (MAT) | a syndrome observed in male athletes that involves three interrelated components: low energy availability, low testosterone levels, and decreased bone mineral density. |
| Malignant tumor | A malignant tumor,** **also known as cancer, is an abnormal growth of cells that can invade and spread to other parts of the body. |
| Marijuana | A drug made from the dried leaves, flowers, stems, and seeds of the cannabis plant, containing THC and other cannabinoids that alter brain function, affecting mood, perception, and behavior. |
| Maslow’s Hierarchy of Needs | A five-tier model of human needs, ranging from basic survival (physiological and safety) to social, esteem, and self-actualization. |
| Maximal Oxygen Consumption or VO₂ max | The highest rate of oxygen consumption an individual is capable of during maximum physical effort, reflecting the body's ability to transport and use oxygen; measured in milliliters if oxygen used per kilogram of body weight per minute. |
| Medication | Prescribed drugs used to manage symptoms of mental health conditions, such as depression, anxiety, bipolar disorder, or schizophrenia, by balancing brain chemistry and improving emotional and cognitive functioning. |
| Mediterranean Diet | A dietary pattern based on the traditional eating habits of countries bordering the Mediterranean Sea, emphasizing fruits, vegetables, whole grains, legumes, nuts, olive oil, fish, and moderate wine consumption, while limiting red meat and processed foods. |
| Melatonin | A hormone produced by the pineal gland that helps regulate sleep-wake cycles and signals the body when it is time to sleep. |
| Menstrual Dysfunction | Any abnormality in the menstrual cycle, such as absent, irregular, heavy, or painful periods, often caused by hormonal, lifestyle, or medical factors. |
| Mental Health | A person’s overall psychological, emotional, and social well-being, influencing how they think, feel, and behave, as well as their ability to manage stress, maintain relationships, and make decisions. |
| Mental Health Disorders | A group of conditions that affect a person’s thinking, mood, behavior, or overall psychological well-being, often interfering with daily life, relationships, and the ability to cope with stress. |
| Mental Illness | A wide range of mental health conditions that affect a person’s thinking, mood, behavior, or overall functioning, often causing significant distress or impairment in daily life. |
| MET | A unit of measure that represents the body's resting metabolic rate - that is, the energy requirement of the body at rest. |
| MET-minute | A measure of training volume equal to exercise intensity expressed in METs times the total exercise time (METs x time). |
| Metabolic rate | The rate at which the body uses energy (calories) to carry out these metabolic processes, including at rest and during physical activity. |
| Metabolic Syndrome | A cluster of conditions — including high blood pressure, high blood sugar, excess abdominal fat, and abnormal cholesterol levels — that occur together, increasing the risk of heart disease, stroke, and type 2 diabetes. |
| Metabolism | The body’s process of converting food into energy; in body composition, metabolism affects how efficiently calories are used for maintaining muscle, storing fat, and supporting overall energy balance. |
| Metastasis | The spread of cancer cells from their original (primary) site to other parts of the body. |
| Methamphetamine | A synthetic stimulant drug that causes a rapid and intense high, followed by dangerous physical and psychological effects. |
| Micronutrients | Vitamins and minerals that the body requires in small amounts for proper growth, development, and overall health. They help regulate processes like metabolism, immunity, and bone health. |
| Mindful Eating | The practice of paying full attention to the experience of eating, including the taste, texture, and smell of food, as well as recognizing hunger and fullness cues, to promote healthier eating habits and improve the relationship with food. |
| Mineral toxicity | Occurs when the body accumulates excessive amounts of a mineral, leading to harmful effects on health. It is usually caused by high-dose supplements or overexposure rather than food sources. |
| Minerals | Inorganic nutrients the body needs in small amounts to support vital functions such as building strong bones, transmitting nerve signals, and maintaining fluid balance. Examples include calcium, iron, potassium, and zinc. |
| Mitochondria | Membrane-bound organelles known as the powerhouses of the cell, responsible for producing ATP (adenosine triphosphate) through aerobic respiration. They play a key role in energy metabolism, especially in muscle cells, which require high energy for contraction. Mitochondria also contribute to cell signaling, apoptosis (cell death), and oxidative stress regulation. |
| Mitral Valve | The heart valve that lies between the left atrium and left ventricle that prevents the back flow of blood into the left atrium. |
| Mobility Exercises | Dynamic movements designed to improve joint range of motion, muscle flexibility, and movement quality. |
| Mode of Transmission | The way in which an infectious agent is transferred from an infected person or animal (source) to a susceptible host (new person or animal). |
| Monogamous | Having or involving a sexual relationship with only one partner at a time. |
| Monosaccharides | They are the simplest form of carbohydrates, consisting of a single sugar molecule such as glucose, fructose, or galactose. |
| Monounsaturated fats | Healthy fats that have one double bond in their chemical structure and can help reduce bad cholesterol levels. They are found in foods like olive oil, avocados, and many nuts and seeds. |
| Mood Disorders | A category of mental health conditions that primarily affect a person’s emotional state, causing persistent feelings of sadness, emptiness, or excessive elation. |
| Motivational Drift | The gradual loss of motivation or drive to maintain a behavior or goal, often occurring when initial excitement fades, progress plateaus, or the behavior becomes routine without ongoing reinforcement. |
| Motivational Enhancement Therapy (MET) | - **Neglect**: The chronic failure to meet an individual’s basic physical, emotional, medical, educational, or safety needs, especially when the person is unable to meet those needs themselves. |
| Motor Neuron | A nerve cell that originates in the central nervous system and sends signals to muscle fibers, causing them to contract. A single motor neuron and all the muscle fibers it innervates form a motor unit. |
| Motor Unit | Consists of a motor neuron and all the muscle fibers it innervates. It functions as a single unit to produce muscle contractions. |
| Mouth | The entry point where food is ingested and mechanical digestion (chewing) begins. |
| Multicomponent Physical Activity | A comprehensive exercise approach that combines aerobic, muscle-strengthening, and balance exercises, particularly beneficial for older adults to address multiple aspects of health and functional ability and reduce the risk of falls |
| Muscle dysmorphia | A subtype of body dysmorphic disorder in which an individual becomes excessively preoccupied with the belief that their body is too small or insufficiently muscular, even if they have above-average muscle size. It is sometimes called “bigorexia” or “reverse anorexia.” People with muscle dysmorphia may engage in compulsive weightlifting, strict dieting, or use of anabolic steroids to increase muscle mass. This condition can negatively affect physical health, mental well-being, social relationships, and daily functioning. |
| Muscle Endurance | the ability of a muscle or group of muscles to sustain repeated contractions or to maintain a submaximal contraction over an extended period of time without fatigue. |
| Muscle Fibers | Muscle fibers are elongated muscle cells responsible for contraction. They contain myofibrils with actin and myosin filaments. |
| Muscle Force | The amount of tension or strength a muscle generates when it contracts to move or stabilize a body part. It is influenced by factors such as muscle size, fiber type, neural activation, and the type of contraction (isometric, concentric, or eccentric). Muscle force is essential for all physical movements, from simple daily tasks to high-intensity athletic performance. |
| Muscle Hyperplasia | The increase in muscle mass due to the formation of new muscle fibers (cells), rather than the enlargement of existing ones (as in hypertrophy). |
| Muscle Hypertrophy | The increase in muscle size due to the growth of muscle fibers, primarily from resistance training or mechanical overload. Hypertrophy is driven by progressive overload, adequate nutrition (especially protein intake), and recovery. |
| Muscle Learning | The process by which repeated practice improves coordination, timing, and efficiency of muscle activation patterns. |
| Muscle Power | The ability of a muscle or group of muscles to exert force rapidly, combining both strength and speed. It reflects how quickly muscular force can be generated to perform an action. |
| Muscle Spindles | Sensory receptors within muscles that detect changes in length and help regulate muscle contraction. |
| Muscle Strength | the maximum amount of force a muscle or muscle group can generate against a resistance in a single effort. |
| Muscular endurance | The ability of a muscle or group of muscles to sustain repeated contractions or maintain a contraction over an extended period of time. It is essential for activities requiring prolonged effort, such as cycling, running, or high-repetition resistance training. |
| Muscular strength | Muscular strength is the maximum amount of force a muscle or muscle group can generate in a single effort. |
| Musculotendinous Junction | The transition area where a muscle connects to a tendon. This region is crucial for force transmission from muscle contractions to the skeletal system, enabling movement. |
| Myocardial infarction (MI) | A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow to the heart muscle decreases or stops in one of the coronary arteries, causing tissue death (infarction). |
| Myofascial Pain | Pain that originates from the muscle and connective tissue (fascia), often due to trigger points. |
| Myofibrils | Long, threadlike structures within muscle fibers (muscle cells) composed of repeating units called sarcomeres, which are the functional units of muscle contraction. They are essential for muscle function and are responsible for the striated appearance of skeletal and cardiac muscle. |
| Myoglobin | An oxygen-binding protein found in muscle tissue that stores and transports oxygen to muscle cells, facilitating aerobic respiration and energy production. It is structurally similar to hemoglobin but has a higher oxygen affinity, allowing muscles to sustain activity, especially during prolonged or intense exercise. |
| Myopathies | A group of neuromuscular disorders characterized by muscle weakness, dysfunction, or degeneration due to abnormalities in muscle fibers. Symptoms often include muscle weakness, fatigue, and, in some cases, pain or stiffness. |
| Myosin Myofilaments | Thick protein filaments in muscle fibers that play a key role in muscle contraction. They are composed of myosin proteins, which have heads that attach to actin filaments to form cross-bridges, generating force through the sliding filament mechanism. |
| Narcolepsy | A neurological disorder that causes excessive daytime sleepiness, sudden sleep attacks, and, in some cases, muscle weakness triggered by strong emotions. |
| Natural Killer (NK) Cells | A type of immune cell that identifies and destroys virus-infected or cancerous cells without prior exposure. |
| Negative Energy Balance | When the body burns more calories than it consumes, leading to weight loss as the body uses stored fat for energy. |
| Neuromotor Exercise | Exercise that involves motor skills such as balance, coordination, gait, and agility (e.g., Tai Chi, yoga). It is primarily relevant for older adults |
| Neuromuscular Adaptation | Early improvements in strength and performance resulting from changes in the nervous system, such as increased motor unit recruitment, firing frequency, synchronization, and reduced inhibitory signaling, rather than muscle hypertrophy. |
| Neuromuscular Junctions | The specialized synapse where the axon terminal of a motor neuron meets a muscle fiber. At this junction, the neurotransmitter acetylcholine is released, triggering the muscle fiber to contract. |
| Neuroticism | A personality trait associated with emotional instability, anxiety, moodiness, and susceptibility to stress. |
| Neurotransmitters | Chemical messengers in the brain and nervous system that transmit signals between neurons, influencing mood, behavior, and bodily functions. |
| Neutral Energy Balance | When the number of calories consumed equals the number of calories the body burns, resulting in weight maintenance. |
| Neutral Spine | A posture where the natural curves of the cervical, thoracic, and lumbar spine are maintained in proper alignment. |
| Nicotine | A stimulant drug that affects the central nervous system, producing short-term pleasurable effects like alertness and relaxation, while also causing dependence and addiction with repeated use. |
| Nicotine Replacement Therapies (NRT) | A tobacco cessation aid that delivers controlled amounts of nicotine to the body to ease withdrawal symptoms and support quitting, while breaking the behavioral habit of smoking or chewing tobacco. |
| Nitric Oxide | A gas released by the endothelial cells to promote blood flow. The capacity of these cells to release nitric oxide is an important marker of good health. |
| Non-Alcohol Fatty Liver Disease | A condition where excess fat builds up in the liver of people who drink little or no alcohol, potentially leading to liver inflammation, scarring, and liver damage over time. |
| Non-Exercise Activity Thermogenesis (NEAT) | The calories burned through daily movements outside of structured exercise (like walking, fidgeting, or doing chores); it contributes to energy expenditure and influences body composition by affecting fat gain or loss. |
| Non-oxidative Energy System | The system that supplies energy to muscle cells for highly intense exercise of short duration by breaking down muscle stores of glucose and glycogen; called the anaerobic system because chemical reactions take place without oxygen and produce lactic acid. |
| Non-REM (NREM) Sleep | The portion of the sleep cycle characterized by slower brain waves, physical restoration, and memory consolidation, divided into stages 1 through 3. |
| Noradrenaline (Norepinephrine) | A hormone and neurotransmitter similar to adrenaline that plays a role in alertness, attention, and the body’s stress response by increasing heart rate and blood flow to muscles. |
| Nucleus Pulposus | The soft, gel-like center of an intervertebral disc that helps absorb compressive forces. |
| Nutrient-dense | Foods that provide a high amount of vitamins, minerals, and other beneficial nutrients relative to their calorie content. Examples include fruits, vegetables, whole grains, lean proteins, and legumes. |
| Nutrient-rich | Foods that supply abundant vitamins, minerals, and other beneficial nutrients with relatively few calories. They support overall health and are often whole, minimally processed foods like vegetables, fruits, and lean proteins. |
| Nutrients | Substances in food that are essential for the body’s growth, development, and overall functioning. Nutrients include carbohydrates, fats, proteins, vitamins, minerals, and water, which are the compounds required for growth and survival that must be obtained from food. |
| Obesity | A medical condition characterized by excessive accumulation of body fat that increases the risk of health problems such as heart disease, diabetes, and certain cancers. It is commonly defined by a body mass index (BMI) of 30 or higher. |
| Occupational Wellness | Finding personal satisfaction and fulfillment in work, balancing responsibilities, and aligning career goals with values, while maintaining a healthy work-life balance. |
| Omega-3 | Essential polyunsaturated fats that support heart, brain, and immune health. They are found in fatty fish, flaxseeds, chia seeds, walnuts, and canola oil. |
| Omega-6 | Essential polyunsaturated fats that help with growth, brain function, and normal development. They are found in vegetable oils, nuts, and seeds, but excessive intake compared to omega-3s may promote inflammation. |
| Opioids | Natural, synthetic, or semi-synthetic substances that interact with opioid receptors in the brain to reduce pain and produce pleasurable effects. |
| Origin | The fixed, proximal attachment of a muscle to a bone, typically the more stable and less movable part during contraction. It serves as the anchor point from which the muscle pulls to create movement at its insertion. |
| Osteoarthritis | A degenerative joint disease where the cartilage that cushions the ends of bones wears down over time, leading to pain, stiffness, swelling, and reduced joint mobility. |
| Osteoporosis | A disease characterized by weakened bones and reduced bone density, increasing the risk of fractures. It often develops with aging and is influenced by factors like low calcium intake, hormonal changes, and lack of physical activity. |
| Outbreak | A sudden increase in the number of disease cases in a particular place and time, beyond what is normally expected. |
| Overgeneralizing | A cognitive distortion where a person draws broad, sweeping conclusions based on a single event or limited evidence, often leading to negative thinking patterns and reinforced anxiety or self-doubt. |
| Overlearning | The practice of continuing to study or rehearse material even after it has been initially mastered, which can improve retention and performance under stress. |
| Overtraining | A condition that occurs when an individual exceeds their body’s ability to recover from intense or excessive exercise, leading to decreased performance, fatigue, increased risk of injury, and other negative physiological and psychological effects. It results from inadequate rest, poor nutrition, or excessive training volume and intensity. |
| Overweight | A condition where a person has more body weight than is considered healthy for their height, typically defined by a body mass index (BMI) between 25 and 29.9. |
| Oxidative (Aerobic) Energy System | The system that supplies energy to cells for long periods of activity through the breakdown of glucose, glycogen, and fats; called the aerobic system because its chemical reactions require oxygen. |
| Oxytocin | A hormone and neurotransmitter involved in social bonding, trust, and stress regulation. |
| Paleo Diet | A dietary pattern based on eating foods presumed to have been available to early humans, focusing on meat, fish, fruits, vegetables, nuts, and seeds, while avoiding processed foods, grains, dairy, and legumes. |
| Pancreas | A yellow, elongated organ that secretes digestive enzymes and bicarbonate into the small intestine. |
| Pancreatitis | The inflammation of the pancreas, a gland that helps with digestion and blood sugar regulation, causing symptoms such as abdominal pain, nausea, vomiting, and digestive problems. It can be acute (sudden) or chronic (long-lasting). |
| Pandemic | An epidemic that spreads globally. |
| Panic Disorder | A mental health condition characterized by recurring, unexpected panic attacks—intense episodes of fear or discomfort—often accompanied by physical symptoms such as rapid heartbeat, sweating, shortness of breath, and a fear of losing control or impending doom. |
| Parasympathetic Nervous System | The division of the ANS that promotes relaxation, recovery, and energy conservation, often referred to as the “rest-and-digest” system. |
| Partially hydrogenated oils (PHOs) | Oils that have been chemically altered to make them more solid and extend shelf life, creating trans fats in the process. Because trans fats raise LDL (“bad”) cholesterol and lower HDL (“good”) cholesterol, PHOs are no longer generally recognized as safe for use in food. |
| Passive Forces | External forces that assist in stretching a muscle, such as gravity, a partner, or equipment. |
| Passive Stretching | A type of stretching in which an external force is used to help stretch the muscle. |
| Passive-Aggressive Behavior | Indirect expression of anger or resentment through subtle, obstructive, or nonverbal actions rather than openly addressing the issue. |
| Pathogens | Microorganisms or infectious agents that can cause disease. |
| Peer Pressure | The social influence from peers that encourages an individual to adopt certain behaviors, beliefs, or actions, often to gain acceptance or avoid rejection. |
| Perceived Control | The belief that one can influence outcomes and events in one's life. |
| Percent Body Fat | The proportion of total body weight made up of fat mass compared to fat-free mass; a key measure of body composition used to assess health and fitness. |
| Percent Daily Values (%DV) | - **Pharynx**: The passage connecting the mouth to the esophagus; involved in swallowing. |
| Perfect Use Effectiveness | - **Portal of Entry****: **The route or pathway through which an infectious agent, such as a virus, bacterium, or parasite, gains access to the body of a host. |
| Perimysium | Is the connective tissue sheath that surrounds and groups muscle fibers into bundles called fascicles. It provides structural support, allows the passage of nerves and blood vessels, and helps distribute force during muscle contraction. |
| Perinatal Depression | A type of depression that occurs during pregnancy or within the first year after childbirth, affecting emotional well-being and daily functioning. |
| Periodization | A structured approach to training that involves dividing a workout program into specific cycles or phases to optimize performance, recovery, and progression. It typically includes variations in intensity, volume, and exercise focus to prevent plateaus, reduce injury risk, and enhance overall fitness gains. |
| Peripheral Nervous System (PNS) | The network of nerves outside the brain and spinal cord that connects the CNS to the rest of the body, transmitting signals to and from organs, muscles, and sensory receptors. |
| Persistent Depressive Disorder (Dysthymia) | A chronic form of depression characterized by a consistently low mood lasting for at least two years, often with less severe but long-lasting symptoms compared to major depression. |
| Personality | The enduring patterns of thoughts, feelings, and behaviors that characterize an individual and influence how they interact with the world. |
| Personality Traits | Consistent characteristics or qualities that influence an individual’s thoughts, emotions, and behaviors across situations. |
| Phobia | An intense, irrational fear of a specific object, situation, or activity that leads to avoidance behavior. |
| Physical activity | Any movement of the body that requires energy expenditure, including daily activities such as walking, household chores, and recreational or structured exercise. It plays a key role in maintaining overall health, improving fitness, and reducing the risk of chronic diseases. |
| Physical fitness | A set of physical attributes that allows the body to respond or adapt to the demands and stress of physical effort. |
| Physical training | A structured and planned regimen of physical activities designed to improve specific aspects of fitness, such as strength, endurance, flexibility, or agility. It involves progressive overload, consistency, and variation to enhance overall performance and health. |
| Physical Violence | The use of physical force with the intent to harm, control, intimidate, or punish another person. It includes actions that cause bodily pain, injury, or physical suffering. |
| Physical Wellness | Maintaining a healthy body through regular exercise, proper nutrition, adequate sleep, and proactive management of health to enhance overall physical functioning and quality of life. |
| Phytochemicals | Naturally occurring compounds in plants that are not essential nutrients but provide health benefits, such as reducing inflammation and lowering disease risk. They are abundant in fruits, vegetables, whole grains, legumes, and tea. |
| Phytosterols | Plant-based compounds structurally similar to cholesterol that can help lower LDL (“bad”) cholesterol levels by reducing its absorption in the intestine. They are naturally found in foods like vegetable oils, nuts, seeds, and whole grains. |
| Pivot Joints | Joints that allow rotation around a single axis, such as the joint between the first and second cervical vertebrae. |
| Plane (Gliding) Joints | Joints that allow sliding or gliding movements, typically found in the wrists and ankles. |
| Plant-based protein | Protein that comes from sources such as beans, lentils, nuts, seeds, soy, and whole grains. While some are incomplete proteins, combining different plant foods can provide all essential amino acids. |
| Plethysmography | A method used to measure changes in volume within an organ or the whole body, often used in body composition testing (such as air displacement plethysmography) to determine body fat percentage by assessing body density through air pressure changes. |
| Polycystic Ovary Syndrome (PCOS) | A hormonal disorder that often affects body composition by increasing fat mass (especially abdominal fat) and making it harder to maintain or build lean muscle. |
| Polyphenols | A large group of plant compounds with antioxidant and anti-inflammatory properties that may protect against chronic diseases. They are abundant in foods such as berries, tea, coffee, red wine, and dark chocolate. |
| Polyunsaturated fats | Healthy fats that contain two or more double bonds in their chemical structure and help reduce LDL (“bad”) cholesterol levels. They are found in foods like fatty fish, walnuts, flaxseeds, and vegetable oils. |
| Portal of Exit | The route through which an infectious agent leaves the body of an infected individual |
| Portion Size | The amount of food or drink a person chooses to consume at one time, which may be more or less than a standard serving size. |
| Positive Energy Balance | When a person consumes more calories than their body uses, leading to weight gain as the excess energy is stored as fat. |
| Positive Psychology | The scientific study of strengths, virtues, and factors that enable individuals and communities to thrive, focusing on enhancing well-being, happiness, and fulfillment rather than solely addressing problems or disorders. |
| Post-Traumatic Stress Disorder (PTSD) | A mental health condition triggered by experiencing or witnessing a traumatic event, characterized by symptoms such as intrusive memories, flashbacks, avoidance of reminders, negative changes in mood or cognition, and heightened arousal or reactivity. |
| Postvention | A set of organized responses and support activities that occur after a suicide to aid survivors in grief, prevent suicide contagion, and stabilize the affected community. |
| Potassium | An essential mineral and electrolyte that helps regulate fluid balance, nerve signals, and muscle contractions. It is found in foods like bananas, potatoes, beans, and leafy greens. |
| Power | The ability to generate force quickly, combining strength and speed to produce explosive movements. It is essential for activities like sprinting, jumping, and Olympic lifting, and is improved through strength and plyometric training. |
| Power Naps | Short naps, usually 10–30 minutes, intended to restore alertness, improve mood, and enhance cognitive performance without causing sleep inertia. |
| Prader-Willi Syndrome | A genetic disorder causing poor muscle tone, insatiable appetite, obesity, developmental delays, and behavioral issues. It has no cure, but symptoms can be managed. |
| Prime Mover | The primary muscle responsible for generating a specific movement. It works with synergists (assistive muscles) and against antagonists (opposing muscles) for controlled motion. |
| Progression | The gradual increase in intensity, duration, frequency, or difficulty of a workout over time to continually challenge the body and improve fitness levels. It is a key principle in training to ensure continuous improvement while minimizing the risk of injury or overtraining. |
| Progressive overload | The gradual increase of stress placed on the body during exercise to stimulate muscle growth, strength, and endurance improvements. This can be achieved by increasing weight, repetitions, intensity, or training volume over time to continually challenge the muscles and promote adaptation. |
| Projection | A defense mechanism where individuals attribute their own unacceptable thoughts, feelings, or traits to others. |
| Proprioceptive Neuromuscular Facilitation (PNF) Stretching | An advanced form of flexibility training involving both stretching and contracting the muscle being targeted. |
| Proprioceptors | Sensory receptors that provide information about body position and movement. |
| Protective Factors | Strengths, supports, or resources that decrease the likelihood of harmful outcomes and increase a person’s ability to cope with challenges or stress. |
| Protein Powder | A dietary supplement made from various protein sources, such as whey, casein, soy, pea, or hemp, designed to support muscle growth, recovery, and overall protein intake. It is commonly used by athletes, bodybuilders, and individuals with increased protein needs. Protein powders come in different forms, including concentrates, isolates, and hydrolysates, each varying in protein content and digestion speed. |
| Proteins | Macronutrients made up of amino acids that build and repair tissues, support immune function, and serve as enzymes and hormones. They are found in both animal and plant-based foods. |
| Psychological Aggression | The use of communication or behavior to inflict emotional pain, exert control, or undermine a person’s sense of self-worth or safety. |
| Psychological Stressors | Internal or cognitive factors that create stress, including worry, fear, perfectionism, low self-esteem, or negative thinking patterns. |
| Psychoneuroimmunology (PNI) | The interdisciplinary study of how psychological factors, the nervous system, and the immune system interact and influence overall health. |
| Psychotherapy | A therapeutic process in which a trained mental health professional uses evidence-based techniques to help individuals explore thoughts, feelings, and behaviors, address mental health concerns, and develop healthier coping strategies. |
| Psychotic Disorders | Severe mental health conditions that affect thinking, perception, and awareness of reality. Individuals may experience hallucinations, delusions, or disorganized thought patterns. |
| Pulmonary Circulation | The part of the circulatory system that moves blood between the heart and lungs; controlled by the right side of the heart. |
| Pulmonary Valve | The heart valve between the left ventricle and the aorta that prevents the back flow of blood into the left ventricle. |
| Range of Motion (ROM) | The full movement potential of a joint, usually its range of flexion and extension. |
| Rating of Perceived Exertion (RPE) | A system of monitoring exercise intensity by assigning a number to the subjective perception of target intensity. |
| Rational Anxiety | A normal, proportionate reaction to a stressful or challenging situation that motivates problem-solving or caution. |
| Rational Fear | A reasonable and appropriate response to a real, identifiable danger. |
| Rationalization | A defense mechanism where individuals justify unacceptable behaviors or feelings with logical or socially acceptable explanations to avoid guilt or discomfort. |
| Reaction Formation | A defense mechanism where individuals unconsciously act in a way opposite to their true feelings to hide or suppress unacceptable emotions or desires. |
| Reaction time | Reaction time is the amount of time it takes for the body to respond to a stimulus. It is a crucial component of athletic performance, especially in sports requiring quick reflexes, such as sprinting, boxing, or tennis. |
| Reciprocal Inhibition | A neuromuscular response where the contraction of one muscle leads to the relaxation of its opposing muscle. |
| Recommended Dietary Allowance (RDA) | The average daily nutrient intake level sufficient to meet the needs of nearly all (97–98%) healthy individuals in a specific age and sex group. It is used as a goal for planning and assessing diets. |
| Recreational Drugs | Psychoactive substances used voluntarily for enjoyment or leisure, rather than for therapeutic or medical purposes. |
| Rectum | The final section of the large intestine, where feces are stored before elimination. |
| Regression | A defense mechanism where individuals revert to earlier developmental behaviors to cope with stress or anxiety. |
| Reinforcement Management | Using rewards to encourage healthy behaviors and reducing the rewards or benefits of unhealthy behaviors. It helps strengthen positive habits through motivation and accountability. |
| REM Sleep | A sleep stage marked by rapid eye movement, vivid dreaming, increased brain activity, and critical roles in emotional regulation and memory processing. |
| Repetition (Rep) | Refers to one complete movement of an exercise, including both the lifting (concentric) and lowering (eccentric) phases. Multiple reps make up a set, and the number of reps performed influences strength, endurance, and muscle growth. |
| Repetition Maximum (RM) | The maximum number of repetitions a person can perform of a given exercise at a specific weight before reaching failure. For example, a 1RM (one-rep max) is the heaviest weight that can be lifted once with proper form, while a 10RM is the heaviest weight that can be lifted 10 times before failure. |
| Repression | A defense mechanism where distressing thoughts or memories are unconsciously pushed out of awareness to reduce anxiety. |
| Reservoir | A place or environment where an infectious agent (such as a virus, bacterium, or parasite) can live and multiply. |
| Resistance Training | A form of physical activity that involves working muscles against an external force—such as weights, resistance bands, or body weight—to improve muscular strength, endurance, and size. |
| Respiratory System | The lungs, airways (like the trachea and bronchi), and the muscles that control breathing, supplies oxygen to the body and removes carbon dioxide. |
| Resting Metabolic Rate | The number of calories the body burns at rest to maintain basic functions; it plays a key role in body composition by influencing how easily someone gains or loses fat and muscle. |
| Resting Metabolic Rate (RMR) | The amount of energy the body uses at rest to perform basic functions such as breathing, circulation, and maintaining body temperature. It is slightly higher than the basal metabolic rate (BMR) because it is measured under less strict conditions. |
| Restless Leg Syndrome (RLS) | A neurological condition causing uncomfortable sensations in the legs and an irresistible urge to move them, often interfering with sleep. |
| Retinol Activity Equivalents (RAE) | This unit is used to measure vitamin A activity from both preformed vitamin A (like retinol from animal sources) and provitamin A carotenoids (like beta-carotene from plants). Because the body converts plant-based carotenoids less efficiently than animal-based retinol, RAE helps standardize the amount of usable vitamin A regardless of the source. |
| Reversibility | Reversibility is the principle that fitness gains and physiological adaptations from exercise are lost when training stops or is significantly reduced. This decline in strength, endurance, and flexibility can occur within weeks of inactivity, emphasizing the importance of consistent physical activity. |
| Rheumatoid Arthritis | An autoimmune disorder causing chronic inflammation of joints, leading to pain and potential joint deformity. |
| Risk Factors | Any attribute, exposure, or situation that raises the probability of a negative health or behavioral outcome. |
| S.M.A.R.T. Goal | A clearly defined objective that is Specific, Measurable, Achievable, Relevant, and Time-bound, designed to enhance focus and increase the likelihood of success. |
| Sacral | Pertaining to the sacrum, the triangular bone at the base of the spine, formed by five fused vertebrae. |
| Sacrum | A large, triangular bone at the base of the spine that connects to the pelvis. |
| Saddle Joints | A type of synovial joint where the articulating surfaces of the bones are shaped like a saddle—concave in one direction and convex in the other. This unique structure allows movement in two planes: flexion/extension and abduction/adduction, making the joint biaxial. |
| Salivary Glands | Located near the mouth, these glands secrete saliva to moisten food and begin the breakdown of carbohydrates. |
| Sarcomere | The basic contractile unit of striated muscle fibers, composed of actin (thin) and myosin (thick) filaments arranged in a repeating pattern. It is the structural and functional unit of muscle contraction. |
| Sarcolemma | the specialized cell membrane that surrounds a muscle fiber (muscle cell). It plays a crucial role in conducting electrical signals (action potentials) and in regulating the exchange of ions, which are essential for muscle contraction. |
| Sarcopenia | An age-related loss of muscle mass, strength, and function, typically beginning around the age of 30 and accelerating with advancing age. It can lead to reduced mobility, increased risk of falls, and decreased quality of life if not addressed through regular physical activity and proper nutrition. |
| Satiety | The feeling of fullness after eating that reduces the urge to eat; it helps regulate calorie intake and influences body composition by affecting fat gain or loss. |
| Saturated fatty acids | Fats in which all carbon atoms are fully “saturated” with hydrogen, containing no double bonds. They are found mainly in animal products and some tropical oils, and high intake is linked to increased LDL (“bad”) cholesterol and heart disease risk. |
| Schizophrenia | A chronic mental health disorder characterized by disruptions in thought processes, perceptions, emotional responsiveness, and social functioning, often including symptoms such as hallucinations, delusions, disorganized thinking, and impaired cognitive abilities. |
| Sciatica | Pain that radiates along the sciatic nerve, typically from the lower back through the hip and down the leg, often caused by nerve compression. |
| Scoliosis | A lateral curvature of the spine that can lead to imbalance and back pain. |
| Seasonal Affective Disorder (SAD) | A type of depression that occurs at a specific time of year, typically during fall and winter, when there is less natural sunlight, and is characterized by symptoms such as low energy, sadness, changes in sleep and appetite, and difficulty concentrating. |
| Sedentary | In general, sedentary behavior refers to any waking behavior characterized by a low level of energy expenditure (less than or equal to 1.5 METs) while sitting, reclining, or lying. |
| Self-actualization | The process of realizing and fulfilling one’s potential, talents, and abilities to achieve personal growth, purpose, and the highest level of self-fulfillment. |
| Self-Compassion | The practice of treating oneself with kindness, understanding, and patience during times of difficulty, rather than engaging in self-criticism, to improve emotional resilience and mental wellness. |
| Self-efficacy | An individual’s belief in their ability to successfully perform tasks, achieve goals, and manage challenges in specific situations. |
| Self-esteem | An individual’s overall sense of self-worth or personal value, encompassing confidence in one’s abilities and respect for oneself. |
| Self-liberation | The process of committing to behavior change based on the belief that change is possible. It involves making a firm decision to act, often supported by goal setting, self-belief, and personal accountability. |
| Self-Reevaluation | The process of reflecting on how a behavior aligns with one’s values, identity, and goals. It helps individuals see how changing a behavior supports the person they want to become, increasing motivation for change. |
| Set | A group of consecutive repetitions (reps) of an exercise performed without rest. Multiple sets are typically performed with short rest periods in between to improve strength, endurance, or muscle growth. |
| Sexual Violence | Any sexual act, attempt to obtain a sexual act, or other act directed against a person’s sexuality using coercion, force, threats, manipulation, or when the victim is unable to consent. |
| Sexually Transmitted Infections (STIs) | Infections that are primarily spread through sexual contact, including vaginal, anal, or oral sex. They are caused by bacteria, viruses, or parasites and can affect anyone who is sexually active. |
| Short-Term Stressors | Stressful events or situations that are temporary and typically resolved quickly. They may cause immediate physical or emotional reactions, such as increased heart rate, tension, or worry, but usually subside once the situation is over. |
| Shoulder Flexibility Test | An assessment that measures the range of motion in the shoulders. |
| Simple Carbohydrates | sugars made up of one or two sugar molecules that are quickly digested and absorbed by the body. They provide a rapid source of energy and are found naturally in fruits, milk, and some vegetables, as well as in processed foods like candy, soda, and baked goods with added sugars. |
| Sit-and-Reach Test | A common test to measure flexibility in the hamstrings and lower back. |
| Skeletal Muscle | A type of striated, voluntary muscle attached to bones via tendons, enabling movement, posture, and stability. It contracts through signals from the nervous system and functions using the sliding filament mechanism. Skeletal muscles also play a role in metabolism and heat production. |
| Skinfold Analysis | A method of estimating body fat percentage by measuring the thickness of skin folds at specific sites on the body using calipers, based on the assumption that the thickness of subcutaneous fat is proportional to total body fat. |
| Skinny-Fat | A body composition where a person has a normal or low body weight but a high body fat percentage and low muscle mass, increasing health risks despite appearing thin. |
| Sleep Apnea | A sleep disorder where a person’s breathing repeatedly stops and starts during sleep, leading to poor sleep quality and low oxygen levels, often causing daytime fatigue, snoring, and increased risk of health problems. |
| Sleep Deprivation | A condition resulting from insufficient sleep, leading to cognitive, emotional, and physical impairments. |
| Sliding Filament Theory | Explains muscle contraction as actin filaments sliding past myosin filaments, shortening the sarcomere. This process, powered by ATP and regulated by calcium, generates muscle force through cross-bridge cycling. |
| Slow-Twitch Muscle Fibers | Muscle fibers that are fatigue-resistant and support endurance activities; in body composition, they contribute to lean mass and help with fat metabolism during prolonged exercise. |
| Small Intestine | – A long, coiled tube where most nutrient absorption occurs; it lies between the stomach and the large intestine. |
| Smokeless Tobacco | Tobacco products that are consumed without combustion, typically by chewing, sucking, or sniffing, and are absorbed through the lining of the mouth or nose. |
| Smooth Muscle Tone | Refers to the continuous, low-level contraction of smooth muscle tissue, which helps maintain organ function and blood vessel diameter. Smooth muscle remains partially contracted even at rest, allowing for sustained control over processes such as blood pressure regulation, digestion, and airway constriction. This tone is regulated by the autonomic nervous system, hormones, and local physiological conditions. |
| Social Anxiety Disorder | A mental health condition characterized by an intense fear of social or performance situations, where individuals worry about being judged, embarrassed, or humiliated, often leading to avoidance and significant distress. |
| Social Liberation | The process of recognizing and using social or environmental supports that encourage healthy behavior change. It involves becoming aware of societal shifts, policies, or resources that make positive change easier and more accepted. |
| Social Stressors | Stress arising from relationships or interactions with others, such as conflict with friends or family, social isolation, peer pressure, or workplace challenges. |
| Social Wellness | The ability to build and maintain healthy, supportive relationships, effectively communicate, and contribute to a connected and positive community. |
| Socioeconomic status (SES) | A person’s social and economic standing, which influences body composition through access to nutritious food, opportunities for physical activity, healthcare, and education about healthy habits. |
| Sodium | An essential mineral and electrolyte that helps regulate fluid balance, nerve function, and muscle contractions. However, excessive intake is linked to high blood pressure and increased risk of heart disease and stroke. |
| Soluble fiber | A type of dietary fiber that dissolves in water to form a gel-like substance, helping slow digestion and regulate blood sugar and cholesterol levels. It is found in foods like oats, beans, apples, and citrus fruits. |
| Specific Phobias | Intense, irrational fears of specific objects, animals, or situations that lead to avoidance and distress. |
| Specificity | Principle that training should be tailored to target specific fitness goals, movements, or muscle groups to achieve optimal performance improvements. It means that adaptations in strength, endurance, or skill development are directly related to the type of exercise performed. |
| Speed | The ability to move the body or a specific body part quickly from one point to another. It is a crucial component in athletic performance and can be improved through sprint training, strength development, and neuromuscular efficiency. |
| Spinal Stenosis | A narrowing of the spinal canal that can compress nerves, leading to pain, numbness, or weakness. |
| Spine | Also called the vertebral column or backbone, is the central support structure of the body. It is made up of 33 individual bones called vertebrae, which are stacked in a column and separated by intervertebral discs. The spine protects the spinal cord, supports the head and torso, and allows for a wide range of movement while maintaining stability. |
| Spiritual Wellness | A sense of purpose, meaning, and connection to something greater than oneself, often involving values, beliefs, or practices that promote inner peace and harmony. |
| Spleen | The largest lymphatic organ, containing white blood cells that fight infection. |
| Spondylolisthesis | A condition in which one vertebra slips forward over the vertebra below it, often causing back pain. |
| Spot Reduction | The belief, and common misconception, that exercising a specific body part will selectively reduce fat in that area. |
| Sprain | An injury to a ligament caused by overstretching or tearing. |
| Stalking | A course of conduct directed at a specific person that would cause a reasonable person to feel fear or distress. |
| Static Flexibility | The ability to hold a stretch at the end of a joint's range of motion. |
| Static Stretch | A stretch that is held in a challenging but comfortable position for a period of time. |
| STD (Sexually Transmitted Disease) | Refers to the condition that develops when an STI causes noticeable symptoms or complications. |
| Steatosis | The build-up of fat in the liver cells, which can impair liver function and, over time, lead to inflammation, fibrosis, and potentially cirrhosis or liver failure. |
| STI (Sexually Transmitted Infection) | Refers to the presence of a virus, bacterium, parasite, or fungus in the body. A person can have an STI without symptoms. |
| Stimulants | Substances that speed up the body’s systems, especially the central nervous system, leading to increased heart rate, blood pressure, and energy levels. |
| Stimulus Control | The process of modifying your environment to support healthy behaviors and reduce triggers for unhealthy ones. It involves adding cues that promote positive habits and removing those that encourage negative ones. |
| Stomach | A J-shaped organ where food is mixed with digestive juices and broken down into chyme. |
| Storage Fat | Body fat stored in adipose tissue for energy reserves; includes subcutaneous fat under the skin and visceral fat around organs, both contributing to overall body composition. |
| Straight Leg Test (SLT) | is a flexibility assessment used to measure the flexibility of the hamstring muscles (the muscles located at the back of the thigh). |
| Strain | An injury to a muscle or tendon caused by overstretching or tearing. |
| Stress | The body’s physical, mental, and emotional response to external pressures or demands. In the context of exercise, stress can be beneficial in promoting adaptations and growth, but excessive stress without adequate recovery can lead to fatigue, injury, or overtraining. |
| Stress Response | The body and mind’s reaction to a stressor, involving physiological, emotional, and behavioral changes. This response prepares an individual to face or adapt to challenges, often triggering increased heart rate, heightened alertness, rapid breathing, and the release of stress hormones such as cortisol and adrenaline. |
| Stress-Management | The use of techniques and strategies to control, reduce, or cope with stress, enhancing overall well-being and resilience in challenging situations. |
| Stressors | Events, situations, or demands that challenge an individual’s ability to cope, potentially causing physical, emotional, or mental strain. Stressors can be short-term, long-term, or recurring, and may include things like exams, work deadlines, major life changes, or interpersonal conflicts. |
| Stretch Reflex or Myotatic Reflex | An automatic muscle contraction in response to stretching within the muscle. |
| Stroke | When blood flow to the brain is blocked, or there is sudden bleeding in the brain. |
| Stroke Volume | The amount of blood the heart pumps with each beat. |
| Subarachnoid Hemorrhage | Bleeding into the space between the brain and the surrounding membrane (subarachnoid space), most often caused by a ruptured aneurysm. |
| Subcutaneous Fat | Fat stored directly under the skin; it is part of total body composition and less harmful than visceral fat, though excess amounts still affect health and appearance. |
| Sublimation | A defense mechanism where unacceptable impulses are transformed into socially acceptable behaviors or activities. |
| Substance Use Disorders | Medical conditions in which the recurrent use of alcohol, drugs, or other substances leads to significant impairment, distress, or health risks. They are characterized by symptoms such as cravings, loss of control, tolerance, withdrawal, and continued use despite negative consequences. |
| Suicide | The intentional, self-inflicted death of an individual. It is typically associated with overwhelming psychological pain, hopelessness, or the belief that life is no longer worth living. |
| Superfood | A term used to describe nutrient-dense foods that are especially rich in vitamins, minerals, antioxidants, and other compounds believed to promote health and reduce the risk of disease. Examples include foods like blueberries, salmon, kale, and chia seeds. |
| Suppressed Anger | The conscious or unconscious inhibition of expressing anger, which can lead to stress, resentment, or negative health outcomes. |
| Susceptible Host | A person who is vulnerable to infection and can be easily affected by a disease. |
| Sympathetic Nervous System | The division of the ANS that prepares the body for rapid action in stressful or threatening situations, often called the “fight-or-flight” response. |
| Synergist | A muscle that assists the primary mover (agonist) in performing a movement by providing additional force or stabilizing the joint. Synergists help refine motion, reduce unnecessary movement, and enhance overall efficiency. |
| Synovial Fluid | A thick, slippery fluid found within synovial joints. It is produced by the synovial membrane and serves several important functions: lubricating the joint to reduce friction between the articulating bones, supplying nutrients to the cartilage, and acting as a shock absorber to protect the joint during movement. This fluid is essential for maintaining healthy, pain-free joint motion. |
| Synovial joints (Diarthroses) | The most common and most movable type of joint in the human body. These joints are characterized by a fluid-filled joint cavity enclosed by a joint capsule, which allows for smooth movement between the articulating bones. The synovial fluid within the cavity reduces friction, nourishes the cartilage, and absorbs shock. Examples of synovial joints include the knee, shoulder, elbow, and hip, each allowing varying types and ranges of motion depending on their structure. |
| Synthetic Cannabinoids | Laboratory-created drugs that interact with the same brain receptors as THC but often in stronger and more unpredictable ways, leading to severe health risks. |
| Systemic Circulation | The part of the circulatory system that moves blood between the heart and the rest of the body; controlled by the left side of the heart. |
| Systole | The period of the heart’s contraction. |
| Target Heart Rate Zones | the range of heart rates that should be reached and maintained during cardiorespiratory endurance exercise to obtain optimal training effects. |
| Tend | -and-Befriend****:** A stress response, often observed in females, involving nurturing behaviors and seeking social support as a coping strategy. |
| Tendons | Strong, fibrous connective tissues that attach muscles to bones, enabling movement by transmitting the force generated by muscles. They are composed primarily of collagen, making them highly resistant to tension while maintaining flexibility. Tendons play a crucial role in stability, mobility, and overall musculoskeletal function. |
| Testosterone Boosters | Supplements designed to naturally increase testosterone levels in the body. They typically contain ingredients like D-aspartic acid, fenugreek, ashwagandha, tribulus terrestris, and zinc, which may support hormone production, improve muscle growth, enhance libido, and boost energy levels. |
| The Transtheoretical Model (TTM) | Explains behavior change through six stages: pre-contemplation, contemplation, preparation, action, maintenance, and termination. |
| Thermic Effect of Food (TEF) | The energy (calories) expended by the body to digest, absorb, transport, and metabolize nutrients from food. |
| Thermogenic Blends | Formulations of ingredients designed to increase the body’s metabolism, enhance fat oxidation, and promote heat production (thermogenesis). These blends often include stimulants like caffeine, green tea extract, capsaicin, and other metabolism-boosting compounds. They are commonly found in weight loss supplements and pre-workout formulas to help improve energy expenditure and fat burning. |
| Thoracic | Pertaining to the middle section of the spine, consisting of twelve vertebrae connected to the ribs. |
| Thymus | A small organ located behind the breastbone where T-cells mature. |
| Tidal Volume | the amount of oxygen entering the lungs with each breath |
| Time | In the context of the FITT principle for weight training, TIME refers to the duration of each workout session or the amount of time spent performing the exercise. |
| Time Management | The practice of planning and organizing how one allocates time to tasks and responsibilities. |
| Tobacco | A plant in the Nicotiana genus, most commonly Nicotiana tabacum, whose leaves are harvested, cured, and processed for use in various products, including cigarettes, cigars, pipe tobacco, and smokeless tobacco |
| Tolerable Upper Intake Levels (ULs) | The maximum daily amounts of nutrients unlikely to cause harmful effects for most people. Consistently exceeding the UL increases the risk of toxicity and adverse health effects. |
| Tolerance | The body’s reduced response to a drug or alcohol after repeated use, requiring higher doses to achieve the desired effect (e.g., euphoria, pain relief, intoxication). |
| Transactional Model of Stress | A framework that explains stress as a dynamic process resulting from the interaction between an individual and their environment, emphasizing how personal appraisal of a situation influences the stress response. |
| Transient Ischemic Attack (TIA) | A brief, temporary episode of stroke-like symptoms caused by a short-lived blockage in blood flow to the brain, with no lasting damage; often called a "mini-stroke" and a warning sign of future stroke risk. |
| Traumatic Brain Injury (TBI) | A disruption in normal brain function caused by an external force, such as a blow or jolt to the head, which can result in cognitive, emotional, and physical impairments. |
| Tricuspid Valve | The heart valve between the right atrium and the right ventricle that prevents the back flow of blood into the right atrium. |
| Triglycerides | The most common type of fat in the body and food, made of three fatty acids attached to a glycerol backbone. They store energy for later use, but high blood levels can increase the risk of heart disease. |
| Trunk Rotation Test | A test used to assess the rotational flexibility of the torso and spine. |
| Type | In reference to the FITT principle, "type" identifies the mode or style of resistance used to develop muscular fitness. This refers to the form of resistance training chosen to improve muscular strength, endurance, or power, and the specific exercises selected to target desired muscle groups. |
| Type A Individuals | People who are competitive, ambitious, impatient, and prone to high stress and urgency. |
| Type B Individuals | People who are relaxed, patient, easygoing, and less prone to stress-related behaviors. |
| Type C Personality | Individuals who tend to suppress emotions, especially negative ones, and may exhibit a high need for approval and compliance. |
| Type D Personality | Individuals characterized by high negative emotions (e.g., worry, irritability) and social inhibition, often linked to increased health risks. |
| Type I Muscle Fibers | Also known as slow-twitch fibers, are skeletal muscle fibers specialized for endurance and sustained, low-intensity activity. They contract slowly, generate less force, and resist fatigue due to their high mitochondrial density and reliance on aerobic metabolism. These fibers are well-suited for activities like long-distance running, cycling, and maintaining posture. |
| Type II Diabetes Mellitus | A chronic condition where the body becomes resistant to insulin or doesn’t produce enough insulin, leading to elevated blood sugar levels and increasing the risk of heart disease, kidney problems, nerve damage, and other health complications. |
| Type II Muscle Fibers | Also known as fast-twitch fibers, are skeletal muscle fibers that contract quickly and generate high force but fatigue faster than Type I (slow-twitch) fibers. They are further divided into Type IIa (fast oxidative-glycolytic) and Type IIb (fast glycolytic) fibers. These fibers are essential for explosive movements like sprinting, jumping, and heavy lifting. |
| Type IIa Muscle Fibers | Also known as fast-twitch oxidative-glycolytic fibers, are a hybrid between Type I (slow-twitch) and Type IIb (fast-twitch) fibers. They contract quickly and generate moderate to high force but have greater endurance than Type IIb fibers due to their ability to use both aerobic and anaerobic metabolism. This makes them well-suited for activities requiring both power and endurance, such as middle-distance running and repeated resistance training. |
| Type IIb Muscle Fibers | Also known as fast-twitch glycolytic fibers, are a type of skeletal muscle fiber that generate high force and contract rapidly but fatigue quickly. They rely primarily on anaerobic metabolism, using stored glycogen for energy, making them well-suited for short bursts of intense activity like sprinting or heavy lifting. However, they have low endurance due to limited oxygen efficiency and a high rate of lactic acid production. |
| Typical Use Effectiveness | - **Vaccination**: Treatment with a vaccine to produce immunity to a particular infectious disease or pathogen. |
| U.S. Department of Health and Human Services (USDHHS) | A U.S. government department responsible for public health. It publishes guidelines like the Physical Activity Guidelines for Americans. |
| Ultra-Processed Foods (UPFs) | Industrially manufactured foods that contain ingredients rarely found in home kitchens, including additives, preservatives, artificial flavors, and sweeteners. |
| Underweight | A body weight that is considered too low to be healthy, typically defined as having a Body Mass Index (BMI) below 18.5. |
| United States Department of Agriculture (USDA) | A federal agency responsible for developing and executing policies on farming, food, and nutrition. It oversees programs like MyPlate, school meals, and food safety regulations. |
| Unsaturated fats | Healthy fats that contain one or more double bonds in their chemical structure, making them typically liquid at room temperature. They include monounsaturated and polyunsaturated fats, found in foods like olive oil, nuts, seeds, and fatty fish. |
| Veins | Vessels that carry blood to the heart. |
| Venae | Cavae**: The large veins through which blood is returned to the right atrium of the heart. |
| Ventricle | One of the two lower chambers of the hear from which blood flows through arteries to the lungs and other parts of the body. |
| Vertebrae | The individual bones that make up the spinal column. |
| Vertebral Column | Also known as the spine or spinal column, is a series of interconnected bones called vertebrae that extend from the base of the skull to the pelvis. It supports the body’s weight, protects the spinal cord, and allows for flexible movement. The vertebral column is divided into five regions: cervical, thoracic, lumbar, sacral, and coccygeal. |
| Visceral Fat | Fat stored deep in the abdomen around internal organs; in body composition, it is linked to higher risks of heart disease, type 2 diabetes, and other metabolic disorders. |
| Vitamin D | A fat-soluble vitamin that helps the body absorb calcium and phosphorus, supporting bone and immune health. It can be made in the skin through sunlight exposure and is also found in foods like fatty fish and fortified milk. |
| Vitamins | Organic compounds that the body needs in small amounts to regulate metabolism, support growth, and maintain health. They are classified as fat-soluble (A, D, E, K) or water-soluble (B-complex, C). |
| Volume | The total amount of work performed in a training session or over a specific period. It is typically calculated as the product of sets × repetitions × weight for resistance training or frequency × duration for aerobic exercise, influencing overall training load and progression. |
| Water | An essential nutrient that supports nearly every body function, including hydration, temperature regulation, nutrient transport, and waste removal. It is the most abundant substance in the human body and must be consumed regularly for survival. |
| Water-soluble vitamins | Vitamins that dissolve in water and are not stored in large amounts in the body, so they must be consumed regularly. They include the B-complex vitamins and vitamin C. |
| Weight Management | The process of adopting long-term lifestyle habits—such as healthy eating, regular physical activity, and behavior changes—to achieve and maintain a healthy body weight. It includes strategies for losing, gaining, or maintaining weight in a way that supports overall health and well-being. |
| Wellness | Wellness is a balanced approach to physical, mental, emotional, and social well-being, achieved through intentional choices like staying active, eating well, and managing stress. |
| Whole grains | Grains that retain all three parts of the original kernel, the bran, germ, and endosperm, after processing. Because these parts are left intact, whole grains are rich in fiber, vitamins, minerals, and beneficial plant compounds. |
| Withdrawal | The body’s response to the absence of a drug on which it has become physically or psychologically dependent |
| Yerkes-Dodson Law | A principle stating that there is an optimal level of arousal for performance, with too little or too much stress impairing effectiveness. |