Excellent article by Gretchen Reynolds of the NY Times (one of the very few credible and thoughtful writers on physical training) about the cellular benefits of hard exercise. Her focus — and the focus of the study she writes about — is the cellular benefit in particular for older adults.

Exercise is as close to magic as you can get for making yourself younger. The impact on genes is powerful and gives lie to the people who believe — mostly wrongly — that genes are destiny.

It seems as if the decline in the cellular health of muscles associated with aging was “corrected” with exercise, especially if it was intense, says Dr. Sreekumaran Nair, a professor of medicine and an endocrinologist at the Mayo Clinic and the study’s senior author. In fact, older people’s cells responded in some ways more robustly to intense exercise than the cells of the young did — suggesting, he says, that it is never too late to benefit from exercise.