Exercise is the best medicine.

If you have an hour, this looks like a pretty good lecture by Harvard's Dr. Lieberman on movement, adaptation, how we made our way to a bipedal gait, and how we got into obesity, heart disease, and finally, using exercise as medicine. I've watched most of it, pretty good if you have an hour play it while you clean up your home office or while you do 100 Hindu squats, 60 pushups, and 10" of planks. :)