I am 36 and although I've been running since collage I don't feel nearly as young. The digestive system is not working as well as when I was 23. The gums in my mouth are receding and since there isn't much on top the barber only takes a couple of minutes with me. In my 20's I didn't need glasses but today the money I pay for eye exams/glasses are quite a burden. My back feels like it is starting to hunch over and my chest is showing signs of sagging. It seems I need more sleep now and feel tired no matter how much sleep I get. I guess an older person has a less refreshing sleep than a younger person. I would probably feel a lot worse without a running lifestyle but running has not stopped the aging process in this case. I would rather be a runner than the cigarette smoking losers I see every morning and evening going in through the office doors. They are hard to miss since they're grouped together inches from the door.