Exercise is good for your mental health so long as you do it in moderation.
Researchers analyzed data from 1.2 million people in the U.S. and found they reported 3.4 days a month of poor mental health on average.
However, those who were physically active had 1.5 fewer "down" days a month compared to those who were not active.
Being active for 45 minutes three to five times a week was associated with the biggest benefit.