Aerobic activities like jogging and interval training can make our cells biologically younger, according to a noteworthy new experiment. But precisely how, at an interior, molecular level, exercise might be keeping us youthful has not been altogether clear. Telomeres seem to protect our DNA from damage during cell division but, unfortunately, shorten and fray as a cell ages. A 2009 study, for instance, found that middle-aged competitive runners tended to have much longer telomeres than inactive people of the same age. But that study was associational; it showed only that older people who ran also were people with extended telomeres, not that the exercise necessarily caused that desirable condition.

Source: New York Times December 12, 2018 10:00 UTC