Depression is a leading cause of disability. In the United States, it is estimated that approximately 16% of the population will meet criteria for major depressive disorder (MDD) in their lifetime, with women being 1.7 times more likely than men to develop the disorder. A recent study demonstrates the positive effects of voluntary exercise and physical activity on mental health.
Physical activity is inversely related to depressive symptoms, possibly conferring a protective effect. This inverse relation is particularly meaningful during midlife because menopause and its accompanying hot flashes, which can last for a number of years, have been associated with increased risk of potentially clinically significant levels of depressive symptoms.
-Source: Medicine & Science in Sports & Exercise, February 2015