Scientists at Tel Aviv University have found what they called a "fountain of youth" for aging muscles--exercise. They showed that endurance exercise can increase the number of muscle adult stem cells, and enhances their ability to rejuvenate old muscles. In a lab version of the rat race, young and old rats ran on a treadmill for 20 minutes a day for a 13-week period (can't you picture them working out in little sweat pants and head bands?) Younger animals showed a 20-35% increase in muscle adult stem cells retained, while older animals showed an even greater benefit, with a 33-47% increase in muscle stem cells, compared to sedentary controls. Endurance exercise also improved the levels of "spontaneous locomotion" in older animals, what the researchers called the feeling that tells our bodies to just get up and dance.

Prof. Dafna Benayahu and her team say their findings, published in PLOS One, explain for the first time why older people who have exercised throughout their lives age more gracefully. As we age, there is a decline in muscle mass and function as well as bone mass; this explains the increased risk of falling in the elderly. She hopes eventually to find a method to ameliorate the negative effects of aging by stimulating adult stem cells in the muscle.

Other studies have shown that exercise can stimulate production of new neurons and new brain cells from adult neural stem cells.

So get up and dance!