Every once in a while my Tae Kwon Do instructor will have a short discussion on ki. During these discussions he always makes note that "this is not religion", which is true. But ki does belong in the mind-body-spirit tradition that is a part of many religions, and it made me think of the relationship of exercise and the major world religions.
Buddhism has a long tradition of having an exercise component, including, of course, martial arts. In fact, Shaolin Buddhist monks are traditionally credited with inventing Kung Fu. Hinduism has Yoga, which is definitely an exercise, which anyone who has taken Yoga will attest (in the West, however, the religious aspect has largely been divorced from the exercise). Islamic exercise consists of maiming, torturing and killing anyone who isn't a Believer, which really burns the calories (ever seen a fat terrorist?). But what about Christianity?
Thinking about sects ranging from Coptic to Catholic I can't think of any that have an exercise component. And it is actually a little curious that the body is left out of the mind-spirit mix since Christianity is actually one of the few religions (and perhaps the only) that actually believes in resurrection of the body as well as the spirit. If Christians are going to get their bodies back one day, one would think that taking care of them, or some sort of exercise, would be a component of this religion as well.