Growth Hormone Does Not Prevent Loss of Muscle Strength

As you age, expect to lose muscle fibers and strength unless you exercise. A study from the University of Florida in Gainesville shows that a program of exercise training later in life helps aging rats to reverse this age-related loss of muscle size and strength (American Journal of Physiology: Regulatory, Integrative and Comparative Physiology, November 14, 2007). The study also showed that short-term administration of growth hormone late in life does not prevent loss of muscle strength. Previous studies show that it may help people get rid of fat.

At this time, there is not enough evidence for an older person to take growth hormone to improve muscle strength, and there is no long-term data on safety. Sudden deaths reported in athletes who have taken growth hormone are probably due to the effect of enlarging the heart muscle without also adequately enlarging the blood supply. The larger heart requires more blood and cannot meet its needs for oxygen, so it starts to beat irregularly. More on growth hormone; growth hormone releasers; growth hormone and aging

Job Fatigue? Carb Snacks Can Help

If you have a physically demanding job that keeps you moving all day, you may have greater endurance if you eat small snacks throughout the day instead of having a single large meal at lunchtime. Researchers at the University of Montana in Missoula showed that snacking on carbohydrates may prolong your endurance during a long day of continuous movement. They asked men and women to exercise intermittently for ten hours. Each hour, they performed nine minutes of upper-body weight lifting, 19 minutes of cycling, and 20 minutes of walking on a treadmill, with a one-minute rest between each exercise. This was followed by a 10-minute rest and feeding period. Those who took carbohydrates every hour were able to keep more sugar (glycogen) in their muscles, and were able to exercise longer without feeling tired. Journal reference

When you exercise, your muscles get their energy from muscle sugar and fat stored in muscles, sugar and fat from the bloodstream, and to a lesser degree from protein. When your muscles run out of their stored sugar, they require more oxygen to burn food for energy. This can make your muscles feel tired and be more difficult to coordinate. Eating any source of sugar or carbohydrates during exercise preserves muscle sugar and increases endurance. More