17.3: Benefits of Physical Activity for Severe Mental Illnesses

A robust body of evidence exists documenting the bidirectional relationship between physical activity and mental health (Firth et al., 2019). In addition, physical activity is increasingly recommended as a routine component of treatment for people with severe mental illness, to protect and promote physical and mental health.

Physical activity is effective in improving cardio-metabolic health through various mechanisms including reduced blood pressure, improved glucose metabolism, and increased cardiorespiratory fitness (Henson et al., 2013). Cardiorespiratory fitness is a key risk factor contributing to the premature mortality in people with severe mental illness (Vancampfort, Rosenbaum, Probst, et al., 2015). Cardiorespiratory fitness is the ability of the heart, circulatory system, and lungs to supply oxygen to the skeletal muscles during physical activity. In the general population, improvements in cardiorespiratory fitness can reduce mortality by up to 13% and impact cardiometabolic risk reduction by 15% (Kodama et al., 2009). For people with severe mental illness, reduction in cardiometabolic risk following participation in an exercise program can occur in as little as 8 weeks of structured exercise (Firth et al., 2015; Vancampfort, Rosenbaum, et al., 2017; Vancampfort, Rosenbaum, Ward, et al., 2015).Additionally, it has been demonstrated that lifestyle interventions incorporating both physical activity and dietary components are effective in preventing the medication-induced weight gain associated with anti-psychotic medication (Alvarez-Jimenez et al., 2008; Curtis et al., 2016; Shiers et al., 2014). Severe mental illness-specific mental health benefits of physical activity are outlined below.

17.3.1. Schizophrenia

Physical activity, particularly performed at a moderate-to-vigorous intensity, can lead to improvements in both positive and negative symptoms for people with schizophrenia (Stubbs et al., 2018). Additionally, global cognition (which refers to a person’s functioning and working memory) improves following physical activity engagement. These cognitive improvements can occur with as little as 90 minutes of physical activity weekly that is of moderate-to-vigorous intensity (Firth et al., 2017). Structured exercise that elicits increased fitness is correlated with increased brain volume,which may impact neurogenesis (the process by which new neurons are formed), through plasticity in the volume of the hippocampal brain region (Pajonk et al., 2010; Scheewe et al., 2013).

17.3.2. Major Depressive Disorder

Physical activity is effective in improving mood and well-being in people with depression following a single session of exercise, particularly those that are of moderate or higher intensity (Schuch, Deslandes, et al., 2016). Additionally, regular participation in physical activity in healthy people is beneficial for reducing future risk of developing depression (Firth et al., 2018). Studies indicate that physical activity is effective in treating mild-to-moderate depression with effects similar to traditional treatments including antidepressant medication and with fewer negative side-effects (and many adjunct positive effects; Schuch, Vancampfort et al., 2016). For people with major depressive disorder, physical activity and exercise is recommended as adjunct to standard care by the World Health Organisation (World Health Organization, 2018). While the mechanisms for how physical activity improves depressive symptoms are not fully clear, research indicates that physical activity can improve abnormal biomarkers associated with major depressive disorder; this can include cortisol reduction and decreases in chronic inflammation (Kandola et al., 2019). For more on the relationship between exercise and depression, see Chapter 15 (Brush & Burani, 2021).

17.3.3. Bipolar Disorder

Early evidence related to the role of physical activity for people with bipolar disorder suggests that physical activity is protective for cardiovascular disease; however, more evidence is needed regarding the impact on mood symptomology (Vancampfort et al., 2018). Research suggests that physical activity may be beneficial for mood fluctuations for people with bipolar disorder due to potential links to improvements to the brain’s functional connectivity (Douw et al., 2014).Cardiorespiratory fitness is associated with health-related quality of life in people with bipolar disorder for both physical and mental health domains (Vancampfort, Hagemann, et al., 2017).

17.3.4. Fitness vs. Fatness

People with severe mental illness are more likely to be overweight and obese, which can also impact participation in physical activity, due to not only reduced fitness, but also perceived pain and poor self-esteem (Mishu et al., 2019; Vancampfort et al., 2011). Achieving significant weight loss is difficult for the general population with only one in 210 males and one in 124 females achieving a healthy BMI (under 25 kg/m2) without surgery (Fildes et al., 2015). Exercise professionals and mental health clinicians should encourage people living with mental illness to engage in physical activity regardless of their body weight and perceived body image. It is important to note that without specialized dietary input, exercise is likely to be ineffective in achieving weight loss for people with severe mental illness (Firth et al., 2015). While this may seem disheartening for people, particularly when trying to engage in physical activity, research tells us that improving fitness can reduce cardiometabolic risk and improve mental health, sleep quality, functional capacity, and cognition, regardless of change in weight. This can be a useful educational and motivational strategy for clinicians to assist clients in increasing physical activity levels.

Learning Exercise Three

Discuss (a) the benefits of physical activity in people with schizophrenia and (b) the mechanisms of how physical activity affects depressive symptoms.