Sports Enhancers: The Good, The Questionable and The Dangerous
Creatine is the latest headline-grabbing substance said to help boost athletic performance. But how does it and other products really fare?

By Edward G. McFarland, M.D.
Director of Sports Medicine

In a world where the difference between champion and loser is measured in hundredths of a second, athletes are willing to do just about anything to gain a competitive edge. When ability has been fully developed and training has maxed out, the next step for many athletes is to take sports-performance enhancers or ergogenic aids -- substances believed to make you bigger, faster and stronger by enhancing the body's energy use.

The use of dietary aids to enhance athletic prowess is as old as competition itself: Centuries ago, men ate ground lion's teeth to give them strength and deer liver to increase their speed. Today, a wide range of substances from coffee to herbal supplements are used by professional athletes and weekend warriors alike for that "edge." The latest to gain attention is creatine, a compounds produced naturally in the body. Reports in the popular press suggest that taking creatine supplements may result in higher energy levels.

Studies do show that high-dose creatine supplements (approx. 20 g/day) can increase the amount of creatine in muscles. But performance data is mixed, with nearly as many studies showing positive results as negative ones. If creatine does work as an ergogenic aid, its benefits will most likely be seen in high-intensity short-burst athletes and in vegetarians. Still, despite often favorable "reviews" in the popular press, its long-term effects are unknown. And since creatine is excreted by the kidneys, there are concerns about possible long-term effects on that organ.

A run-down of other popular so-called "sports enhancers":

Protein
Since muscles are composed of protein, some athletes believe that eating more protein will translate into more muscle. While athletes may require slightly more protein than non-athletes to build muscles (but not enhance performance), this extra amount is usually fulfilled by a balanced, varied diet. In fact, the typical American diet usually provides more than the recommended 15 percent of calories from protein -- more than enough to aid muscle intregrity.
Advice: Unless you're a strict vegetarian, you don't need to increase protein consumption to boost athletic performance.

Amino acids
Over-the-counter amino acids have become a popular ergogenic supplement sold in health food stores because they are theorized to build muscle, accelerate the rate of recovery during training and generally improve both psychological and physiological responses during endurance training. Yet research studies have not demonstrated benefits to most athletes.
Advice: Amino acids are ineffective and their long-term health effects are unknown.

Coenzyme Q10
Coenzyme Q10 (also known as CoQ10) is a type of lipid found in the energy producing mitochondria of cells. Some benefit of CoQ10 supplementation has been seen in patients with heart disease, including improvement in exercise capacity, but ergogenic improvements are generally not seen in healthy subjects.
Advice: Don't waste your money.

Caffeine
Affordable and readily available in coffee or tea, caffeine seems to be among the few ergogenic aids that have been shown to work in a number of scientific studies. The caffeine equivalent of 2 cups of coffee ingested before exercise increases endurance in both well-trained and weekend athletes. The theory is that caffeine stimulates the breakdown of fats for energy which slows the depletion of glycogen, the main energy stores of the body.
Caffeine doesn't seem to improve performance during conditions of high heat, and it can have harmful side effects if you have heart disease.
Advice: If you're already a coffee-drinker, have 2 cups about 2 hours before activity.

Chromium picolinate
This trace mineral has generated a lot of interest -- and publicity -- for its alleged ability to build muscle, burn fat and increase energy. Research has not supported these claims.
Advice: Chromium picolinate may improve glucose tolerance (making it useful to diabetics or those prone to diabetes), but it does nothing to improve athletic performance or burn fat.

Ginseng
Ginseng is an herbal plant that has been used as a medicinal for thousands of years in China and Korea, and more recently has been "discovered" in the U.S. and touted as a possible ergogenic. It's available in supermarkets and health food stores as supplemental pills, powders and in teas.
Advice: Research has found that ginseng does not improve oxygen use, aerobic performance, exercise recovery rate or mood.

Anabolic steroids
Anabolic steroids are substances that are similar to the naturally-occurring hormone testosterone, which helps regulate growth and sexual development in men. Steroids are popular among weight lifters and track and field athletes because of their ability to increase muscle size and strength.
Advice: The price far outweighs the benefits. Serious and sometimes irreversible side effects include liver damage, liver cancer and heart disease. In addition, the improvements made with steroids usually disappear when their use is discontinued.

Growth hormone
Growth hormone is taken by athletes who believe that it will build muscle and strength the way anabolic steroids do, but without the dangerous side effects. They are wrong. Although very little research has been done on its effects on athletes, it seems that growth hormone does not result in the kind of muscle growth seen with steroid use and it does not improve athletic performance, strength or endurance. Further, the side effects can be severe.
Advice: Downright dangerous! Large quantities taken during the development stage can impair normal growth and hormonal balance. It is a banned substance for most athletic competitions.


Edward G. McFarland, M.D., is a former Academic All-American college football player, is an Associate Professor of Medicine and Director of the Sections of Sports Medicine and Shoulder Surgery. He is Orthopaedic Consultant to the Baltimore Orioles and other athletic teams.
Last updated August 15, 1998