The study was led by Matthew Pearce, PhD, who analyzed and compiled reports regarding the benefits of physical activity on depressive symptoms, including data collected from the U.S., Australia, Japan, India, Ghana, Mexico and Russia.
The study found that the participants who saw the most significant improvement of depression symptoms were among those who went from no physical activity to some physical activity, compared to those who went from low to high levels of exercise.
The study found that just 2.5 hours a week of walking — the minimum recommended level — contributed to a 25 percent lower risk of depression, and those meeting half the recommended level had an 18 percent lower risk of depression.