Mental Health and Exercise

Exercise directly benefits mental health, above and beyond the benefits of exercise-derived improvements in physical health.

Exercise helps relieve tension, anxiety, stress, anger, and depression, and enhances feelings of wellbeing. Exercise and improved physical fitness build self-confidence, enhance self-image and self-esteem, and contribute to a positive outlook. Sports and other physical activities can be exhilarating and provide emotional release from anxieties and frustrations. Exercise increases energy levels and mental alertness and improves sleep, all of which contribute to good mental health. Exercising outdoors in the sunlight, or engaging in “green” activities, can help overcome seasonal affective disorder (SAD), sometimes called the “winter blues.” Many people find exercise to be an enjoyable form of relaxation and an opportunity for socializing. This can be especially important for individuals dealing with isolation and loneliness due to a mental health condition.

Over the long term, regular exercise benefits physical health, which contributes to improved mental health. Weight gain is both a common cause and a common result of depression and other mental health problems and can be a side effect of some medications used to treat mental disorders. Exercise can slow or halt weight gain. It can also relieve stress and tension that can lead to overeating. Aging often has a negative impact on mental health; however, physical activity can help seniors continue to enjoy activities and remain independent, both of which are important contributors to good mental health.

For many people, the effects of exercise on mental health go beyond improving mood and preventing the blues. Research and clinical experience indicate that exercise can be an effective treatment for more serious mental disorders, including severe depression, anxiety disorders, substance dependence, and even schizophrenia. Physicians and psychologists commonly prescribe exercise for a range of mental health conditions, in place of or in addition to, medications and counseling or psychotherapy. Some research suggests that the effects of exercise on mild depression may be longer lasting than the effects of antidepressants.

According to the World Health Organization, as of 2016 an estimated 350 million people worldwide were affected by depression, 60 million by bipolar disorder, 21 million by schizophrenia, and 47.5 million by dementia. Mental illness affects an estimated 13 million American adults each year, with anxiety disorders the most prevalent. Although regular physical activity is important for the mental health of most people, activity levels have decreased in recent decades among all age groups. During the same period, the incidence of mental health disorders has risen sharply. Although some of this increase is attributable to greater awareness of mental health issues and improved diagnoses, reduced activity levels may share some of the blame.

During the 1970s and 1980s, clinicians began to realize that people who exercised regularly were less likely to experience depression and/or become depressed in the future. Robert N. Butler, founding director of the National Institute on Aging, stated in the 1980s: “If exercise could be packed in a pill, it would be the single most widely prescribed and beneficial medicine in the nation.” A trial conducted in 1999 demonstrated that an aerobic exercise plan was as effective in treating depressed adults as the antidepressant sertraline (Zoloft), a drug that earned its manufacturer more than $3 billion annually before its patent expired in 2006. Most subsequent studies have confirmed that regular aerobic exercise can be as effective as medication for treating depression and preventing the recurrence of depressive symptoms. In 2007, the American College of Sports Medicine and the American Medical Association launched an initiative to make exercise and physical activity a standard component of disease prevention and treatment. Also, Healthy People 2020 (a government initiative which began in 2010 by the Department of Health and Human Services) aims to “promote quality of life, healthy development, and healthy behaviors across all life stages.”

The effects of exercise on mental health are emotional, psychological, and physical, with particularly profound effects on the prevention and alleviation of stress disorders and depression. Exercise relaxes the mind and body. Physical activity provides a positive means of coping with stress, anxiety, sadness, and depression. It provides a distraction that can break cycles of negative thinking, which increase anxiety and depression. In contrast, trying to wait out depression or attempting to cope using drugs or alcohol often worsens symptoms. The numerous benefits of exercise on mental health are hardly surprising, because the human brain most likely evolved to cope emotionally and psychologically under much more physically demanding conditions than are common in the 21st century.

Exercise can relieve muscle tension, burn off stress hormones, and increase blood flow to the brain. Stress and anxiety cause the brain to release cortisol, a fight-or-flight stress hormone. Exercise may reduce cortisol levels through exposure to controlled stress, which tightens regulation of the brain's stress response so that it is less likely to launch inappropriately. Exercise also increases body temperature, which may have a calming effect. Exercise may lower levels of immune system proteins that can worsen depression.

Exercise appears to have a direct effect on nerve cells in the hippocampus, the part of the brain involved in regulation of mood and responses to antidepressants. Exercise stimulates the production of brain-derived neurotrophic factor (BDNF), and higher levels of BDNF are associated with aerobic exercise-induced increases in hippocampal volume. Yoga practice has been show to shrink the amygdala, a brain structure involved in processing stress, anxiety, and fear.

A 2014 study reported that exercise training improves the production of enzymes in skeletal muscle that can clear the blood of a harmful metabolite that accumulates during stress. This may be another biochemical mechanism by which exercise protects against and counteracts depression.

Exercise has several advantages as a mental health treatment. It is usually viewed in a positive light, without the stigma that is sometimes still associated with medication or psychotherapy. The mood-enhancing effects of exercise are quickly apparent much more quickly than the physical benefits of exercise, and this immediate effect encourages more exercise. This is particularly important for people with depression, which is characterized by a chronic lack of motivation. Unlike other treatments for mental disorders, exercise provides significant physical health benefits, is inexpensive or free, and without the side effects that limit the use of many medications. In addition to relieving symptoms of depression and anxiety, exercise may modestly improve symptoms of schizophrenia and dementia.

As little as 30–45 minutes of walking 3 times per week has been associated with a reduction or alleviation of depressive symptoms. Even small increments of exercise, such as climbing stairs, walking the dog, or gardening for 10–15 minutes at a time, can have a significant effect. More vigorous exercise, such as running or playing a sport, may work even more quickly. Anaerobic exercise, such as weightlifting, may have many of the same mental health benefits as aerobic exercise. Some types of exercise, such as yoga, Pilates, and tai chi, are geared specifically toward improving mental and physical health.

In 2016, the American College of Sports Medicine and the Society of Behavioral Medicine released a statement calling for increased healthcare plan coverage of exercise programming to treat serious mental illnesses. Unfortunately, most healthcare professionals have only limited knowledge about prescribing exercise, often simply telling patients that they should exercise more.

Sedentary individuals and those with health problems should always consult their physicians before embarking on new exercise programs. Physicians and mental health professionals should prescribe exercise regimens that take into account pain, physical limitations, and mobility issues. It is important to start slowly, gradually increasing exercise intensity and duration as strength and stamina improve.

Regardless of its mental health benefits, sticking with an exercise program is a challenge for many people; therefore, it is important to choose activities that are both appropriate and enjoyable. Exercise should be something to look forward to each day. Goals should be reasonable and achievable, so as not to set oneself up for failure. Some people prefer to exercise at home because of self-consciousness or financial considerations. Others find that exercising with companions is more motivating and enjoyable.

Although exercise can ease symptoms of anxiety, depression, and other mental disorders, it is not necessarily a substitute for psychotherapy, medication, or other treatment. Appropriate activities and intensity levels should be chosen in consultation with a physician to avoid the risk of injury.

Compulsive exercise is sometimes a symptom of a mental health disorder, particularly eating disorders such as anorexia or bulimia. People with anorexia may exercise compulsively to inappropriately lose weight. Those with bulimia, which is characterized by episodes of uncontrollable binge eating, may engage in compulsive exercise to prevent weight gain.

As little as 30 minutes or less of moderate-intensity exercise that raises the heart rate can result in noticeable mood enhancement and anxiety reduction. Just five minutes of aerobic exercise can begin to lower anxiety, and some studies suggest that a 10-minute walk can be as effective as a 45-minute workout at temporarily relieving anxiety and depression. However, some research suggests that psychological responses to exercise have a genetic component and that not all people obtain mental health benefits from exercise; some evidence suggests that this is due to variations in genes that encode receptors for dopamine or that interfere with the release of dopamine. It is also unclear whether exercise is as effective for treating severe depression as it is for treating mild-to-moderate depression.

The relationship between mental health and exercise is an area of active research. One study reported that people who regularly exercise vigorously have a 25% reduced risk of developing depression or an anxiety disorder over a five-year period. A 2013 meta-analysis of research studies indicated that both aerobic and resistance exercise appeared to be as effective as antidepressants and psychological treatments in relieving depressive symptoms. Studies have extended the mental health benefits of exercise to patients with schizophrenia and schizophrenia-like illnesses, bipolar disorder, major depression, and other mental disorders. Exercise has been found to relieve depressive symptoms in adult stroke patients, and stroke patients who exercise are much less likely to report depressive symptoms. The amount of exercise by undergraduate students has been found to correlate positively with their ratings on mental health scales.

A study involving more than 40,000 Norwegians reported that those who engaged in even small amounts of light, regular exercise were less likely to have depressive symptoms, as long as it was leisure-time exercise rather than physical activity at work. Socializing during exercise was an important beneficial factor. Those who were not active during their free time were almost twice as likely to have depressive symptoms. Exercise intensity did not appear to influence the results.

Exercise interventions have been found to improve attention and mood in children, with the largest improvements in children diagnosed with attention-deficit hyperactivity disorder (ADHD). Yoga has been found to reduce aggression and improve emotional balance in children and appears to be particularly helpful for children with special needs, as well as those with eating and mood disorders and autism.

Margaret Alic, PhD