Many entrepreneurs like to project an image of themselves as solely positive-thinking, productive leaders with a special immunity against negativity, but research has shown that founders are over four times as likely to have a history of depression as the general public.

That’s nearly a third of entrepreneurs at risk of having a depressive episode. Some have learned how to manage their mental health issues, but others may still need the tools and information to do so.

Now, research out of Harvard University and Massachusetts General Hospital (MGH) finds that blocking out a small amount of time each day for exercise may actually provide a little of that imagined immunity against depression for entrepreneurs, and anyone else.