Adults who are physically active are healthier and less likely to develop many chronic diseases than adults who are inactive. They also have better fitness, including a healthier body size and composition. These benefits are gained by men and women and people of all races and ethnicities who have been studied.
Overall Components of Physical Fitness:
- Cardiorespiratory fitness – ability to sustain aerobic activity for a prolonged period of time
- Muscular strength – amount of force a muscle is able to exert in one contraction
- Muscular endurance – ability of the muscle to continue to perform without fatigue
- Flexibility – ability to move joints freely through their full range of motion
- Body Composition – the relative proportions of fat mass and lean mass in the body
The Physical Activity Guidelines for Adults include three main recommendations: Avoid inactivity, do aerobic activity, and strengthen muscles.
All adults should avoid inactivity. Some physical activity is better than none, and adults who participate in any amount of physical activity gain some health benefits.
Do Aerobic Activity
In this kind of physical activity (also called cardiorespiratory fitness), the body’s large muscles move in a rhythmic manner for a sustained period of time. Brisk walking, running, bicycling, jumping rope, and swimming are all examples.
Aerobic activity causes a person’s heart to beat faster than usual.
Aerobic physical activity has three components:
- Intensity, or how hard a person works to do the activity. The intensities most often examined are moderate intensity (equivalent in effort to brisk walking) and vigorous intensity (equivalent in effort to running or jogging);
- Frequency, or how often a person does aerobic activity; and
- Duration, or how long a person does an activity in any one session.
For substantial health benefits, adults should do at least one of the following:
- 150 minutes (2 hours and 30 minutes) each week of moderate-intensity aerobic physical activity (such as brisk walking or tennis)
- 75 minutes (1 hour and 15 minutes) each week of vigorous-intensity aerobic physical activity (such as jogging or swimming laps)
- An equivalent combination of moderate- and vigorous-intensity aerobic physical activity
For additional and more extensive health benefits, adults should increase their aerobic physical activity to one of the following:
- Increase moderate-intensity aerobic physical activity to 300 minutes (5 hours) each week
- Increase vigorous-intensity aerobic physical activity for 150 minutes (2 hours and 30 minutes) each week
- An equivalent combination of moderate- and vigorous-intensity activity
Aerobic activity should be performed in episodes of at least 10 minutes, and preferably, it should be spread throughout the week.
Examples of Different Aerobic Physical Activities and Intensities
Aerobic Intensity: Target Heart Rate Zone
One way of monitoring physical activity intensity is to determine whether a person’s pulse or heart rate is within the target zone during physical activity.
When starting an exercise program, calculating a target heart rate zone can be very beneficial to ensure that you are exercising safely and effectively. Heart rates are referred to as “beats per minute” or bpm. The maximum rate is based on the person’s age. An estimate of a person’s maximum age-related heart rate can be obtained by subtracting the person’s age from 220.
220 – Age = Maximum Heart Rate
For moderate-intensity physical activity, a person’s target heart rate should be 50 to 70% of his or her maximum heart rate. For vigorous-intensity physical activity, a person’s target heart rate should be 70 to 85% of his or her maximum heart rate.
Example of Target Heart Rate for a 50 year old adult:
220 – 50 years = 170 beats per minute (bpm).
The 50% and 70% levels would be:
Thus, moderate-intensity physical activity for a 50-year-old person will require that the heart rate remains between 85 and 119 bpm during physical activity. Vigorous intensity for a 50-year old adult would be a heart rate between 119 - 145 bpm.
Taking Your Heart Rate
Generally, to determine whether you are exercising within the heart rate target zone, you must stop exercising briefly to take your pulse. You can take the pulse at the neck, the wrist, or the chest. We recommend the wrist. You can feel the radial pulse on the artery of the wrist in line with the thumb. Place the tips of the index and middle fingers over the artery and press lightly. Do not use the thumb. Take a full 60-second count of the heartbeats, or take for 30 seconds and multiply by 2. Start the count on a beat, which is counted as “zero.” If this number falls between 85 and 119 bpm in the case of the 50-year-old person, he or she is active within the target range for moderate-intensity activity.
Find your Target Heart Rate Zone
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Do muscle-strengthening activities (such as lifting weights or using resistance bands) that are moderate or high intensity and involve all major muscle groups on 2 or more days a week.
Muscle-strengthening activities provide additional benefits not found with aerobic activity. The benefits of muscle-strengthening activity include increased bone strength and muscular fitness. Muscle-strengthening activities can also help maintain muscle mass during a program of weight loss.
Muscle-strengthening activities make muscles do more work than they are accustomed to doing. That is, they overload the muscles. Resistance training, including weight training, is a familiar example of muscle-strengthening activity. Other examples include working with resistance bands, doing calisthenics that use body weight for resistance (such as push-ups, pull-ups, and sit-ups), carrying heavy loads, and heavy gardening (such as digging or hoeing).
Muscle-strengthening activities count if they involve a moderate to high level of intensity or effort and work the major muscle groups of the body: the legs, hips, back, chest, abdomen, shoulders, and arms. muscle strengthening activities for all the major muscle groups should be done at least 2 days a week.
No specific amount of time is recommended for muscle strengthening, but muscle-strengthening exercises should be performed to the point at which it would be difficult to do another repetition without help. When resistance training is used to enhance muscle strength, one set of 8 to 12 repetitions of each exercise is effective, although two or three sets may be more effective. Development of muscle strength and endurance is progressive over time. Increases in the amount of weight or the days a week of exercising will result in stronger muscles.
Muscle-strengthening activity also has three components:
- Intensity, or how much weight or force is used relative to how much a person is able to lift;
- Frequency, or how often a person does muscle strengthening activity; and
- Repetitions, or how many times a person lifts a weight (analogous to duration for aerobic activity). The effects of muscle-strengthening activity are limited to the muscles doing the work. It’s important to work all the major muscle groups of the body: the legs, hips, back, abdomen, chest, shoulders, and arms.
This kind of activity (sometimes called weight-bearing or weight-loading activity) produces a force on the bones that promotes bone growth and strength. This force is commonly produced by impact with the ground. Examples of bone-strengthening activity include jumping jacks, running, brisk walking, and weight-lifting exercises. As these examples illustrate, bone-strengthening activities can also be aerobic and muscle strengthening.
To review the key recommendations, as well as learn more about “what counts” as moderate or vigorous intensity aerobic activity, watch the videos below:
You Tube Video: Physical Activity Guidelines -- Introduction (https://youtu.be/nhECLmOznoM)
You Tube Video: Physical Activity Guidelines - What Counts As Aerobic? (https://www.youtube.com/watch?v=GEvJlmpZCoM)
Contributors and Attributions
Public domain content
- Physical Activity Guidelines. Authored by: Office of Disease Prevention and Health Promotion. Provided by: U.S. Department of Health and Human Services. Located at: https://health.gov/paguidelines/guidelines/adults.aspx. License: Public Domain: No Known Copyright
- Videos - Physical Activity Guidelines. Authored by: CDC. Located at: https://youtu.be/GEvJlmpZCoM. License: Public Domain: No Known Copyright
- Components of Physical Activity. Authored by: Office of Disease Prevention and Health Promotion. Provided by: U.S. Department of Health and Human Services. Located at: https://health.gov/paguidelines/guidelines/chapter2.aspx. License: Public Domain: No Known Copyright
- Target Heart Rate and Estimated Maximum Heart Rate. Authored by: Centers for Disease Control and Prevention. Provided by: U.S. Department of Health and Human Services. Located at: http://www.cdc.gov/physicalactivity/basics/measuring/heartrate.htm. License: Public Domain: No Known Copyright