The largest known study of its kind included 1.2 million people, showing team sports, gym workouts, cycling, and aerobics were associated with the most benefits. Exercising for 45 minutes 3-5 times per week was associated with the greatest decreases in poor mental health. Exercise was not always beneficial as exercising for more than 3 hours a day was associated with increased risk of poor mental health; and was noted that people who exercise excessively may have obsessive tendencies that may increase risks.
Data was used for 1.2 million people that completed the Behavioural Risk Factor Surveillance System surveys in 2011, 2013, and again in 2015. Participants reported how many days they classed their mental health as not good, and how often they performed exercises outside of work.
After adjusting for factors such as income, marital status, race, age, BMI, previous diagnosis of depression, education level, and employment status the average number of days reported as being of poor mental health was 3.4 in 30 days, with participants who exercised reporting 3.4 fewer days of poor mental health; and the largest decrease in numbers of poor mental health days was seen among participants with previous depression diagnosis.
75 types of exercises were reported which were all associated with improved mental health. Strongest improvements were seen in those who had performed team sports, aerobics, and gym exercise. Duration and frequency of exercising was found to be an important factor, 3-5 times per week was shown to have had better mental health than those who exercised less. 30-60 minutes duration was associated with the greatest benefits, and more than 3 hours a day was associated with worse mental health outcome than not doing any exercising.
It was concluded that exercise is associated with lower mental health burden across participants regardless of age, gender, race, education level, and income. Findings are being used to develop and personalize exercise recommendations to match people with specific exercise regimes to help improve mental health.
