The ability of exercise to reduce depression has long been known, and many supporting studies have been published for the last few decades. Fortunately, you don't have to run to reap the benefits. Not everyone is physically able to run, or even jog. Walking regularly can have a significant effect on depression. I think one of the better studies showed that we should walk 5 days a week, for at least a half hour, for the best benefit. http://www.health.harvard.edu/newswe...rt-excerpt.htm
Also noted: Another theory is that exercise stimulates the neurotransmitter norepinephrine, which may directly improve mood.
It appears to me that moderate exercise is much more beneficial than light exercise, which might not help some people. Since the effects are generally seen with regular
exercise, it is important to keep going and not give up
I was clinically depressed in the early 90s, and my doctor recommended regular walking. It really did help.