The reduction in depression symptoms with exercise is greater for those who were the most depressed at the start of the exercise program, and for older people. Recent studies collectively confirm that exercise can exert positive mental health benefits across different age groups and populations of different health status. Also, there is a progressive reduction in depressive symptoms with a longer duration of exercise participation and a greater frequency of exercise per week.
How much exercise for mental wellness?
A study finds that improvement of vigor, fatigue, and total mood scores occurred after only 10 minutes of exercise at 60% VO2max intensity level. There was progressive improvement in confusion after 20 minutes, but no further additional scores over longer periods.
In Finland, a population study of 3,403 participants ranging from ages 25-64 years found that those engaged in moderate exercise 2-3 times a week experienced significantly less depression, anger, distrust, and stress compared to those who exercise less or not at all. These results support the current recommendations that healthy adults should participate in a total of at least 30 minutes of moderate exercise daily, which can be accumulated in bouts throughout the day.
Proposed mechanisms for how exercise improves mood are speculative at present. One possible mechanism is biochemical changes, such as an increased level of endorphins, leading to subsequent binding to endogenous opioid receptors in the brain and a sense of wellbeing. Physical activity may also lead to a good night’s sleep.
Mental benefits may also be explained in psychological terms. Improved self-image and self-esteem can result from weight loss and enhanced muscle tone, and may reduce negative self-evaluation associated with depression. Exercise may also distract or serve as a time-out from daily hassles and stress.
An often cited reason for not exercising regularly is lack of time. However, since mental health benefits occur quickly and the recommended amount of daily exercise for physical fitness can be accumulated throughout the day, one only has to take 10 minutes 3 times a day to get the benefits and keep mentally and physically fit.