This is an excerpt from Christian Paths to Health and Wellness 3rd Edition With Web Study Guide-Loose-Leaf Edition by Peter Walters & John Byl.
Anxiety, stress, and depression are the most common mental disorders today and affect primarily young adults. A growing body of research has investigated the mental benefits of exercise (Barbour et al., 2007; Brupbacher et al., 2019; Deslandes et al., 2009; Hearing et al., 2016; Hicks et al., 2019; Kandola et al., 2019; Kiuchi et al., 2012; Perraton et al., 2010; Rahman et al., 2018; Tonello et al., 2019); for an excellent review, see Hearing et al. (2016). Even a single bout of exercise enhances mood and reduces anxiety. Measuring the effects of a single acute bout of exercise is a little tricky because it is usually done by having participants complete a mood questionnaire before and after exercise. Immediately postexercise, especially if that exercise is of a high intensity, people may have poor mood and high anxiety for a few minutes. However, repeated testing shows that after as little as 10 minutes, one can measure profound improvements in mood that last two to four hours before mood returns to its normal state (Raglin et al., 2007). These mood improvements with a single bout of exercise are seen in healthy people as well as those with emotional disorders. While acute effects of exercise are measured using mood questionnaires, chronic effects of exercise are measured by identifying psychological traits that indicate how someone feels in general, so the results are unaffected by transitory events or activities.
Some reports suggest that a regular exercise program is as effective as medication and therapy in the treatment of depression (Blumenthal et al., 2007; Perraton et al., 2010). In one U.S. study, those who participated in a six-month exercise program reduced medication and were less likely to relapse than those taking only medication (Babyak et al., 2000). It should be noted that the placebo effect is high in depression treatment, indicating that patient expectations have a role in treatment success, both pharmaceutical and exercise. Exercise has a proven preventative role, and fitness level matters. In a systematic review including over 27,000 adults, low fitness was associated with a 47 percent greater risk of common mental health disorders, whereas for moderate fitness that number was 23 percent (Kandola et al., 2019). Cardiorespiratory fitness was the only independent predictor of depression scores (Tonello et al., 2019). After a 12-week supervised program involving 55 minutes of either vigorous aerobics and strength training, moderate-intensity aerobics classes, or light-intensity yoga stretching and balancing, cardiorespiratory fitness predicted depression severity and better treatment response even three months later, regardless of the program's exercise intensity (Rahman et al., 2018). Although benefits are greater with higher fitness, lower levels of exercise are valuable, and any exercise is better than none. Physical exercise is inexpensive and has no side effects; instead, it offers a plethora of positive outcomes in addition to improving depression. The mechanisms responsible for these results are still under investigation, but different possibilities have been considered (Mikkelsen et al., 2017; Raglin et al., 2007). The reasons fitness is related to better mood indicators (such as stress, anxiety, and depression) include immune factors and physiological factors (Mikkelsen et al., 2017). The runner's high, a feeling of peace and euphoria reported by long-distance runners, has been attributed to the effects of various pathways, such as endorphins and opioids (Hicks et al., 2019). It has also been suggested that exercise may alter one or more of the neurotransmitters responsible for mood, such as norepinephrine, dopamine, and serotonin. Brain-derived neurotrophic factor, which stimulates brain neural development, has also been considered. Alternatively, an increased body temperature with exercise may increase brain activity and relax muscles. Activity alone has psychosocial benefits, regardless of intensity or duration. A psychosocial mechanism that has received a good deal of attention is distraction, suggesting that exercise offers a significant distraction from the stressors of routine life and offers a new environment, life activity, and sometimes social interaction. Another psychosocial mechanism may be mastery, which suggests that successfully completing a bout of exercise or following a long-term plan improves mood through improved self-efficacy. Self-efficacy (the belief in one's own ability) is improved with exercise and may also play a role in reducing symptoms. Further research is required to determine the mechanisms responsible for enhanced mood with exercise and to determine the dose-response relationship. It should be noted that too much exercise can elevate anxiety, depression, and anger, as documented in studies of overtraining in serious recreational athletes or higher-level athletes (Raglin et al., 2007). The current exercise recommendation for improved mood is moderate-intensity exercise for at least 30 minutes, three times per week (Perraton et al., 2010).