Oral Creatine Supplementation: Separating Fact from Hype
abstract & commentary
Synopsis: No evidence is given to support an ergogenic effect of creatine supplements in sporting activities such as running, swimming, or cycling. Potential complications are noted from the use of creatine as a dietary supplement.
Source: Juhn MS. Oral creatine supplementation: Separating fact from hype. Phys Sportsmed 1999;27(5):47-50ff.
Juhn provides an excellent review of the current thinking with regard to use of oral creatine supplementation to enhance athletic performance. He notes the small number of good scientific articles that exist in the literature. While there is some evidence that these supplements can enhance performance in repeated short bursts of stationary cycling and weightlifting, there is no evidence to support an ergogenic effect on other sporting activities such as running, swimming, or even cycling on the road. He clearly identifies some potential complications from the use of creatine as a dietary supplement. It has been repeatedly shown that a modest weight gain occurs after the typical loading dose is taken over a five-day period and that this weight gain is probably due to water retention and not to an acute gain in muscle mass. Muscle cramping, gastrointestinal complaints, renal dysfunction, and dehydration all have been reported as complications of the use of creatine. The weight gain due to water retention may decrease performance, offsetting any potential ergogenic effect of the creatine. Juhn concludes this excellent review by stating, " the evidence that creatine improves running and swimming performance is not convincing [and] creatine has not been shown to be ergogenic outside the laboratory setting."
Comment by James D. Heckman, MD
This is an excellent review of a controversial subject. The enthusiastic endorsement of creatine dietary supplements by celebrity athletes has led to their common consumption among athletes at all levels. Juhn provides a comprehensive list of references that will facilitate anyone’s study of this subject. The actual number of well-performed clinical studies on the effect of oral creatine supplementation is quite sparse, and little is known about the specific ergogenic mechanisms if, indeed, they do exist. Juhn clearly points out that there have been no studies performed in the pediatric population with regard to the effect of creatine oral supplementation. Yet, young athletes may be more susceptible to the influence of the advertising campaigns and take the supplement despite the fact that there is little or no evidence that it can be helpful. This is an article that should be read by all trainers and sports medicine physicians who wish to be informed about the benefits and effects of creatine in their athletes.
46. Any ergogenic benefit of oral creatine supplementation in running or swimming may be offset by:
a. obligatory weight gain.
b. decrease in alkaline phosphatase.
c. creatine phosphokinase inhibition.
d. alteration in the performance of fast twitch muscle fibers.