Exercise Rejuvenates the Body

As noted earlier, mitochondrial degradation is a primary culprit in dwindling muscle mass. But recent evidence indicates that exercise can slow down this effect. According to Mark Tarnopolsky, a professor of pediatrics and medicine at McMaster University in Hamilton, Ontario, resistance training activates a muscle stem cell called a satellite cell. In a physiological process known as ‘gene shifting,' these new cells cause the mitochondria to rejuvenate. Tarnopolsky claims that after six mon...

 The Effects of Aging and How Exercise Counteracts Them

• Motor neurons die, particularly from age 60 onward. This causes connections between muscle fibers to wither — and that, in turn, eventually leads to loss and shrinking of muscle fibers. As a result, muscles get smaller and a person gets weaker, says Sandra Hunter, an associate professor of exercise science at Marquette University in Milwaukee. "Physical activity can offset some of that," she says. "But there is this biological aging process going on — the neurons will die regardle...