Intake: Food for the Fastest?
By Elaine Appleton

There's a point in an afternoon of rock climbing or pool intervals when most athletes would resort to PowerBar by injection if it meant an instant surge of energy. But load carbos as you will, this slowly metabolized fuel isn't going to meet any brief, high-intensity demands. Recent studies suggest that creatine phosphate supplements may step in where carbos decline to sprint--to help you overcome muscle fatigue for explosive, repetitive, short-term activity.

A nitrogen-based compound that occurs naturally in the liver, creatine helps in the production of adenosine triphosphate (ATP), the body's most elemental energy-producing molecule. But because ATP isn't naturally made in large enough quantities to suit our power-craving needs, the logic goes that a little additional creatine will help replenish our ATP supplies. "If creatine is proven to have any benefit, it's for short bursts of speed," says Ann Grandjean, director of the International Center for Sports Nutrition in Omaha, Nebraska. "It's the nutritional equivalent of being able to run a four-minute mile, even though you can't run two miles in eight minutes."

Creatine supplementation is still experimental, but many experts are excited about its potential. The Karolinska Institute, a sports physiology research facility in Stockholm, Sweden, recently concluded that indeed the supplements can enhance the force of muscle contraction. Says Kristine Clark, director of sports nutrition at Penn State University, "It might be something that in another year we'll recommend across the board."

Meanwhile, Grandjean suggests that athletes who add creatine to their diets evaluate it during training rather than just before a competition. It comes in powder and pill form, and a dose of three to five grams a day during training is usually recommended to build reserves in the muscles. You might want to up your intake slightly before a race, but as with many other supplements, megadoses of creatine can stress the kidneys. But don't expect it to change your sporting life. "If we had found the magic bullet," says Grandjean, "we could quit looking."