How Exercise Keeps Us Young - NYTimes.com

Active older people resemble much younger people physiologically, according to a new study of the effects of exercise on aging. The findings suggest that many of our expectations about the inevitability of physical decline with advancing years may be incorrect and that how we age is, to a large degree, up to us.
http://mobile.nytimes.com/blogs/well/2015/01/07/how-exercise-keeps-us-young/