Depression and Exercise
Recent studies found that even exercising 1 or 1.5 times a week had a significant effect in preventing depression. The study investigators estimated that compared with individuals who did not exercise, those who exercised an hour or more a week had a 44% decreased odds ratio of becoming depressed.
The researchers also noted that if depression was a causal factor, about 12% of cases could be prevented if all adults exercised for a little over an hour a week.
So along with core-strengthening exercises, strength training, and stretching, I highly recommend that twice a week you do high intensity interval training which raise your heart rate up to your anaerobic threshold for 20 to 30 seconds, followed by a 90-second recovery period.