Exercise can help address, prevent or lessen the risk of a host of diseases and illnesses - including mild to moderate depression. Research shows that walking on a treadmill or riding a stationary bike for 30 minutes several times per week may be as effective as taking antidepressant medications or using cognitive-behavioral therapy. (Dr. Weil recommends walking – especially outdoors - for at least 30 minutes per day, most days per week, for the most benefit.) While moderately intense aerobic exercise has the best results, any exercise is beneficial. Even those performing low-intensity aerobic workouts and stretching can show improvement. Try it for a few weeks and see how it affects your mood.