Research supports weight lifters' belief in creatine

April 17, 2000
Web posted at: 9:59 AM EDT (1359 GMT)

(WebMD) -- It comes in a bewildering number of products, from MuscleTech and Cell-Tech to Champion Creatine Xtreme and Twinlab Creatine Fuel 5000. Day after day, weight lifters and athletes from junior high to pro leagues are swallowing gram after gram of the stuff.

It's called creatine, a naturally occurring substance found in muscles and other tissues. Proponents say the supplement can safely add muscle and improve performance. Surprisingly, a growing number of sports medicine experts say they just might be right.

Joe Tevella, 40, has been lifting weights on and off for 20 years. For the past 18 months, he's been especially dedicated, pumping iron at home four days a week -- and taking a daily dose of creatine.

"I was surprised, because usually you hear all this stuff (about supplements) and they don't work," he says. With creatine, however, he has seen definite changes. "The biggest difference is I feel a lot fresher when I work out," he says. "It has helped me get a little stronger. I have grown a little bit in size. Plus, it gives me quicker recovery."

Unlike much of what you find on the shelves of health food stores, creatine has been put to the test in well-designed, placebo-controlled studies. At the Human Performance Laboratory at Ball State University in Muncie, Indiana, for instance, assistant professor Jeff Volek, Ph.D., R.D., and his colleagues measured the effects of creatine on performance and muscle size in 10 healthy men and compared them with nine men taking a placebo.

After 12 weeks of heavy training, the men taking 5 grams of creatine per day showed a 6.3 percent increase in body mass, compared with a 3.6 percent increase in the group taking a placebo. The creatine group lifted 24 percent more weight doing bench presses, while the placebo group managed only 16 percent more.

Other studies have shown similar gains in squats, according to the August 1999 issue of Medicine and Science in Sports and Exercise, the official journal of the American College of Sports Medicine. Creatine also produced greater increases in muscle-fiber cross-sectional areas -- all without notable side effects.

Still there's reason to be cautious. Although creatine has been well studied compared to most performance enhancing supplements, "most of the research has been on short-term use and in young individuals. Long-term studies on the daily use of creatine for more than a few months have not been done," says Ray Sahelian, M.D., the author of Creatine: Nature's Muscle Builder.

What's more, overdoing creatine can cause trouble. The short-term side effects of taking more than 5 grams a day include nausea and diarrhea, according to Sahelian. "Long-term side effects with daily dosages of greater than 10 grams a day may include harm to the kidneys, especially in those with kidney disease." Sahelian currently does not recommend it for teenagers or individuals older than 80 because of potential stress on the kidneys.

Even the possible benefits of creatine don't always live up to the hype. "These are pretty minor to moderate increases," says Volek, who conducted the Ball State University study. "Nonetheless, they are statistically significant. There is certainly an abundance of literature showing a positive effect, but I think we have to put it into perspective." For 10 to 30 percent of those who try creatine, it doesn't do a thing -- perhaps because they already have such high creatine levels that taking supplements creates no useful effect.

For professional athletes, a small gain in energy or performance can mean the difference between winning and losing. "Does a 2 or 3 percent increase in performance mean something to a weekend warrior?" says Volek. "That's a question they have to ask themselves."

Tevella, for one, will tell you it's worth it. He has increased his bench press from around 240 pounds a few years ago to as high as 320 pounds now. He credits creatine for his recent gains. "It makes me feel like I have more energy," he says.

© 2000 Healtheon/WebMD. All rights reserved.

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