Anabolic steroids are banned by the world's major sports organizations because they cause liver damage and heart attacks. As a result, many athletes looking to become stronger are taking growth hormone instead. Yet a recent study has shown that growth hormone is not altogether effective in making an athlete stronger and also has serious side effects.
Kevin Yareshevsky of Washington University in St. Louis tested growth hormone against placebos in young men who also lifted weights. The growth hormone did not make them stronger.
But the study may be flawed. Earlier studies on average lifters showed that anabolic steroids did not make them stronger, because they were not already lifting at their maximum ability. When these same studies were repeated on world-class athletes, amazing gains in muscle size and strength were realized. This was because the world-class athletes were already working at their maximum. The anabolic steroids helped them recover faster so they could train more; the increased workload made them stronger, not just the steroids.
The same flaw in study design may apply to growth hormone. Mediocre weight lifters do not benefit from growth hormone because they are not already working at their maximum.
The growth hormone study did, unfortunately, find disturbing side effects. Growth hormone causes the bones of the wrist to pinch nerves in the hands, a condition called carpal tunnel syndrome. It can also cause diabetes and hip joint damage.
Q: My trainer says that my muscles burn during exercise because of lactic acid. What is lactic acid? Is there any way to fight it?
A: Your muscles get energy from a series of chemical reactions that process the foods you eat. As long as there is enough oxygen in your body to keep these reactions going, food is broken down completely to produce energy, water and carbon dioxide, which you blow off from your lungs.
When you exercise intensely, the chemical reactions occur at such a fast rate that you eventually cannot get all the oxygen you need to convert food to carbon dioxide and water. The reactions stop and lactic acid accumulates in your muscles. Lactic acid makes your muscles acidic, causing them to lose their ability to contract effectively. They start to burn and hurt. This response is not harmful in itself, but it can make you uncomfortable.
If you slow down, the rate of the chemical reactions will slow down. You'll catch up on your oxygen debt, and the lactic acid will be properly converted to energy, water and carbon dioxide.
If you are a competitive athlete, you can train your muscles to be more efficient and tolerant of large amounts of lactic acid. To do so, you'll need to exercise very intensely after you feel the burning in your muscles.
If you are a recreational exerciser and not a masochist, you don't need to exercise so hard that you find yourself gasping for breath and experiencing terrible burning and pain in your muscles. Just slow down when you start to feel such uncomfortable sensations.
Q: Is it a good idea to take mineral pills every day?
A: You do not need to take mineral tablets; you can meet your need for minerals by eating a varied diet. Taking excessive amounts of minerals when you don't need them can be harmful.
The only mineral deficiencies that are common in this country are those of calcium and iron. Taking extra calcium does not prevent osteoporosis, a weakening of the bones, even though a diet that does not provide adequate amounts of calcium can cause the condition. But if you do not eat dairy products or soft-boned fish (salmon and sardines), you probably should take up to 750 milligrams in calcium pills or powder each day.
You should not take iron pills unless you lack that mineral; your doctor can test you to be sure. Once iron is stored in your body, the only way it can get out in significant amounts is when you bleed. Excessive amounts of iron can build up in your tissues and damage them.
The only way that healthy people can develop a mineral deficiency is by taking mineral-draining medications or by eating only plant foods grown in mineral-deficient soil. Since the plant foods you eat are grown in soil from all over the world and it is virtually impossible for all soil to lack the same mineral, you can get all the minerals you need just by eating a variety of fruits, vegetables, whole grains and beans.
Dr. Mirkin is a practicing physician in Silver Spring specializing in sports medicine and nutrition.