The Lifestyle

Two Surprising New Discoveries About Exercise

September 5, 2012

Two amazing research studies published over the past year have challenged some major scientific assumption about exercise. Both studies found that regular, intense exercise has much more potential than previously thought to give us strong, lean and slender bodies all our lives.

The first study, printed by The Physician and Sports Medicine Journal last November, looked at 40 master athletes (20 men and 20 women) whose ages ranged from the 40 to 81 years, all of whom trained intensely 4 to 6 times a week. The authors of the study wanted to investigate whether the ill effects of aging “ loss of muscle mass and strength, resulting in falls, functional decline, and the subjective feeling of weakness “ are due to muscle aging or to muscle disuse. Their 40 subjects endured a series of strength tests and had MRIs made of their quads (as shown). Their findings were astonishing. At age 60, the master athletes lost a small amount of strength and mass. After that, they lost no strength and no muscle mass. The outcome of their work, in the authors words, contradicts the common observation that muscle mass and strength decline as a function of aging alone. Instead, these declines may signal the effect of chronic disuse rather than muscle aging.

The second study, this one investigating the effect of exercise on appetite, was published in February by the Journal of Applied Physiology and covered later by the New York Times. The authors of the study wanted to know if exercise increases or decreases appetite and if so, whether it influences the types of foods people crave. For their subjects they recruited 30 fit male and female athletes in their 20s, all students at California Polytechnic. The researchers told half of them to work out strenuously for an hour and half to sit for an hour. Then they attached electrodes to the volunteers heads (I love when scientists do this) and showed them photos of different kinds of foods. As the subjects looked at the photos, the scientists noted how much their brains food-reward systems lit up. Heres what they found: In the volunteers whod been sitting for an hour, the New York Times reported, the food-reward system lit up, especially when they sighted high-fat, sugary items. But if they had worked out for an hour first, those same people displayed much less interest in food, according to their brain scans. The researchers switched the roles of the two groups of volunteers got the same results.

But does exercise have the same appetite-suppressing effect on sedentary people? Not as much, according to another similar study using electrodes done on 34 overweight

subjects. Exercise did lower the appetites of 20 of the volunteers, and they lost an average of 11 pounds each. The remaining 14 members of the group were not as fortunate. Their brains food-reward networks, as the New York Times put it, lit up riotously after exercise at the sight of food. Its likely that, in order to achieve weight loss and weight maintenance, concludes the leader of the Cal-Poly study Todd A. Hagobian, you need to do a fair amount of exercise and do it often.

Bar Method student Christine Binnendyk learned this from personal experience. “Funny how I can be ravenous for a big lunch on less physical days, yet a light lunch entirely satisfied me on more active days,” she wrote me.  “The longer I live, the better I become at hearing what my body is telling me.”

Where does this new research leave the millions of the sedentary people in the world today? Will it make any real difference going forward in how much people exercise?  Next month: some good news on this front.