Exercising too much may worsen mental health
Small reductions were still seen for people who exercised more than 90 minutes a day, but exercising for more than three hours a day was associated with worse mental health than not exercising at all.
"Previously, people have believed that the more exercise you do, the better your mental health, but our study suggests that this is not the case," said Adam Chekroud, an assistant professor at Yale University in the US.
While some evidence suggests that exercise may improve mental health, the relationship could go both ways - for example, inactivity could be a symptom of and contributor to poor mental health, and being active could be a sign of or contribute to resilience.
Researchers said that their study cannot confirm cause and effect.
In the study, researchers used data from 1.2 million adults across all 50 US states who completed a survey in 2011, 2013, and 2015.
The reduction in a number of poor mental health days was larger for people who had previously been diagnosed with depression, where exercise was associated with 3.75 fewer days of poor mental health compared with people who did not exercise - equivalent to a 34.5 percent reduction.
Even completing household chores was associated with an improvement.
Exercising for 30-60 minutes was associated with the biggest reduction in poor mental health days. However, exercising for more than three hours a day was associated with worse mental health than not exercising at all.
(This story has not been edited by Devdiscourse staff and is auto-generated from a syndicated feed.)