Studies have consistently shown that physical activity can help treat depression, and on the flipside, that low activity levels are a big risk factor for it. The antidepressant effect of exercise seems to be moderated in part through serotonin, the brain chemical that’s targeted with some antidepressants, and in part through bone-derived neurotrophic factor (BDNF). And this goes back to the generation of new cells mentioned earlier—exercise, though various mechanisms, seems to make the brain more plastic and more capable of growing new cells.
Whether we’re fully conscious of it or not, we’re always looking for how to be happy. And exercise is one of the most obvious steps to take, as it’s not a coincidence that you feel better after a good workout: It’s science. A Penn State University study found that people who exercised, whether it was a mild, moderate or vigorous workout, had more pleasant feelings than those who didn’t. (1)