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Food Supplement Creatine Can Build Muscle, But Risks Unknown

September 12, 1996

The strength coach of the San Francisco 49ers believes in the food supplement called creatine, and many scientists agree with him.

Creatine, they say, can help athletes build short-term performance power and long-term muscle.

``I would say that anyone that is a serious strength-power athlete may benefit from creatine supplementation,″ said Michael Barnes, the 49ers strength development coordinator. ``It could be a recreational athlete as well.″

But the experts are split on whether it’s fair for athletes to use creatine for competition, and it isn’t known whether the supplement has any long-term risk.

Creatine is a protein, produced in the body and obtained from food such as meat. It’s stored in the muscle and is broken down in the early phase of exercise. Creatine releases its energy to let the muscle rebuild supplies of energy-rich adenosine triphosphate, ATP, the main fuel for sprinting or intense weight training.

Probably at least three quarters of the 49ers have used it or are using it now, Barnes said.

Saturating the muscle by using creatine gives the athlete a greater ability to recharge ATP, said researcher Richard B. Kreider of the University of Memphis.

This lets sprinters keep going flat-out a little longer and recover from the stress of exercise a little faster, he said. Using the supplement may add another 2 seconds of full energy to a 100-meter run. For an elite athlete, that can be enough to complete the entire race at peak performance, according to Kreider.

The additional energy stores can fuel more exercise, adding extra pounds of muscle, Kreider said.

``There’s pretty good evidence that when you include creatine in training, it gives you greater quality of training, and that may lead to greater mass gains as well as strength gains,″ he said.

Barnes estimates that an athlete capable of 10 repetitions on a 275-pound weight without using creatine might be able to do 12 or 13 with it.

But there are limits to creatine’s benefits. It apparently doesn’t help endurance, said Boyd Epley, athletic performance director at the University of Nebraska, Lincoln.

Endurance activities such as distance running rely on breaking down the sugar glycogen, not ATP, as their muscle fuel source.

Athletes with normally high creatine levels won’t get as much benefit as athletes with low levels, Barnes said. However, most sprint or strength athletes can expect see some improvements.

Once muscle cells are saturated with creatine, the need to take more diminishes, said William J. Kraemer, a researcher at Pennsylvania State University. An athlete can take 20-25 milligrams a day for 7 days, then cut back to a maintenance level of 3-5 milligrams, he said.

There have been some reported health problems associated with creatine, Kreider said.

Some athletes have reported cramps while using the supplement. But the cramps might have other causes, such as not getting enough water in hot weather, he said. Some experts think the added pounds that result from creatine supplementation are largely water.

Athletes with kidney problems should play it safe by staying away from the supplements, because creatine is broken down in the kidneys, said researcher Gary I. Wadler, a supplement expert and an assistant professor professor of medicine at Cornell University Medical College. And he warns that the use of creatine supplements is relatively new, so the long-term effects are not known.

Although creatine supplements are legal and their use isn’t regulated by the NCAA, U.S. Olympic Committee and pro leagues, there is the ethical question of whether sports should allow them, Wadler said. A case can be made for including them among other performance-enhancing drugs.

Kreider, however, disagrees. The powders and tablets are made from food sources, and therefore are no different from high-carbohydrate food mixes for aerobic athletes, he said.

``We should emphasize that the alternative to creatine is steroids,″ he said.

End advance for Sept. 14-15

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