The Use Of Creatine In Athletics

Creatine is a compound produced by the body that helps release energy in muscles. Unlike androstenedione, scientific research indicates that creatine can boost short-term bursts of power.

Creatine helps muscles make and circulate more adenosine triphosphate (ATP), the fuel the body uses for quick, explosive activity of short duration like weightlifting or sprinting. Creatine also reduces energy waste products. As a result, it's purported to enhance performance and decrease fatigue.

A normal liver makes about 2 grams of creatine each day. Creatine also is readily available from meat in your diet. Creatine levels are relatively easily maintained, and muscles can store creatine. The kidneys remove excess levels of the substance, which casts some doubt on whether creatine supplements are of any value to someone who already has a high muscle creatine content.

Athletes participating in strength training programs may benefit from creatine supplementation, according to a study published in the Journal of The American Dietetic Association (JADA), the most widely read, peer-reviewed journal in the dietetics field.

The study, conducted at The Pennsylvania State University Center for Sports Medicine, showed that short-term supplementation with creatine monohydrate significantly increased muscular performance and body mass during multiple sets of bench presses and jump squats in college men who routinely participate in strength training.

The JADA study is unique in that it focused on the effects of short-term creatine supplementation on muscular performance and showed a positive association with supplementation. Previous studies on creatine supplementation have examined effects on cycling, running, jumping and knee extensions, while few have looked at resistance exercise.

Study subjects were instructed to maintain their normal eating plans and kept food records (checked by registered dietitians) throughout the study to ensure that increases in body mass might not be attributable to increases in calorie intake.

In another study the authors assessed the safety and efficacy of creatine monohydrate (Cr) in various types of muscular dystrophies in a double-blind, crossover trial. Thirty-six patients (12 patients with facioscapulohumeral dystrophy, 10 patients with Becker dystrophy, 8 patients with Duchenne dystrophy, and 6 patients with sarcoglycan-deficient limb girdle muscular dystrophy) were randomized to receive Cr or placebo for 8 weeks. There was mild but significant improvement in muscle strength and daily-life activities by Medical Research Council scales and the Neuromuscular Symptom Score. Cr was well tolerated throughout the study period.

The safety of creatine supplements was called into question in December, 1997, after three collegiate wrestlers died, and it was speculated that creatine may have contributed to their deaths. However, these wrestlers were undergoing dangerous dehydration procedures that more than likely resulted in fatal thermal stress. Any contribution that creatine may have had has not been proven. Anecdotal information from athletic trainers suggested a relationship between creatine and muscle cramps, muscle spasms, and even pulled muscles. It was postulated that the increased water retention in muscle may have caused these problems, but this has never been examined or documented. Although laboratory studies have reported minimal or no side effects of creatine ingestion, these studies have used protocols of a relatively short duration (from 4 days to less than two months). The long-term use of high doses of creatine has not been examined. The manufacturer's recommended dose is usually 20 gram of creatine per day for 5 d and then continuing on a maintenance program of 2-5 g per day. Athletes could be taking higher doses for longer periods of time, thinking that if a little is good, more is better. Further research on the long-term effects of creatine supplements at various doses are needed to determine whether creatine ingestion is safe and under what circumstances one may need to exercise caution.

- Mayo Foundation for Medical Education and Research. MUSCLE-BUILDING Do andro, creatine work?
- The American Dietetic Association, Study Says Creatine Supplementation May Enhance Muscular Performance During High-Intensity Exercise
- Walter MC, Lochmuller H, Et al. Creatine monohydrate in muscular dystrophies: A double-blind, placebo-controlled clinical study. Neurology 2000 May 9;54(9):1848-50

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