By Gretchen Reynolds, New York Times Health Blog
The sedentary older subjects had telomeres that were on average 40 percent shorter than in the sedentary young subjects, suggesting that the older subjects’ cells were, like them, aging. The runners, on the other hand, had remarkably youthful telomeres, a bit shorter than those in the young runners, but only by about 10 percent. In general, telomere loss was reduced by approximately 75 percent in the aging runners. Or, to put it more succinctly, exercise, Dr. Werner says, ‘‘at the molecular level has an anti-aging effect.