Does creatine enhance physical performance?
In determining the efficacy of creatine administration, both theoretical and clinical studies must be looked at. Theoretically, the use of creatine by athletes is a means by which
phosphocreatine stores can be increased. Phosphocreatine, as explained in the “mechanism of action” section of this website, is linked to a quick and readily available form
of energy for muscle activity. Thus, a person with higher stores of phosphocreatine should have enhanced performance when it comes to activities requiring short bursts of energy. A
person with higher stores of phosphocreatine would also be able to recover faster from periods of strenuous activity. Thus theoretically, creatine is beneficial as a physical performance
enhancer. This statement is certainly true when tested during short-term clinical studies. Of the many studies done, most have shown an increase in performance regarding muscle strength
in high intensity activities.
What trials have been done?
Study 1:
A random collection of four clinical studies is used to illustrate the short-term efficacy of creatine supplementation. The first study measured the force generated by isometric
bench-presses in 32 resistance-trained men. It was a double-blind study where half the group were given a placebo, and the remainder given creatine supplements. In a double-blind
study, neither the conductor of the experiments, nor the subjects are aware of which samples are real and which samples are the placebo. Subjects were monitored for strength before
and after a five-day supplementation. The results showed a greater average increase in both muscle growth and peak force exhibited by the creatine supplemented group over the placebo
supplemented group. (1)
Study 2:
The second study conducted was similar to the first, only that active older men between the ages of 59 and 72 were used as subjects to see if the supplementation of creatine had the
same effect regardless of age. Measurements were done before and after a seven-day supplementation of creatine, resulting in a greater overall increase muscle mass and maximal force
seen in the non-placebo group. (2)
Study 3:
A third experiment involving the double-blind study of 19 trained male handball players introduced the measurement of both high-intensity physical performance as well as muscle
endurance. Once again, an improvement was seen regarding the high-intensity energy output, but the benefit of creatine supplementation on muscle endurance was hardly as impressive.
Subjects were examined for endurance through a running test where creatine supplementation did not show any improvement upon average muscle endurance in the subjects involved. (3)
Study 4:
A group of eleven untrained males aged between 18 and 25 years were used in a double-blind study in a fourth trial measuring isometric force similar to that of the three studies already
examined. A short-term study was completed measuring muscle performance over a ten-day supplementation. Unlike the positive results seen in the three previous short-term studies
however, this trial showed no mean influence upon isometric strength enhancement. (4)
Conclusion
From the four studies examined here, it can be seen that in short-term trials, the average effect of creatine supplementation is to enhance the performance of muscle force and increase
mean muscle mass. In the case where creatine supplementation did not follow this trend, as in trial four, there was certainly no muscle degeneration seen. Creatine could thus be seen to
be beneficial in the enhancement of short-term high-intensity physical activity. The results gained from muscle endurance tests however, indicate that creatine would be unlikely to improve
performance in sports where prolonged activity is needed.
Furthermore, because commercially marketed creatine products do not meet the same quality control standards of pharmaceuticals, there is always a concern of impurities or doses higher
or lower than those on the labelling. Individuals should balance
the quality of information supporting the use of creatine with the known and
theoretical risks of using the supplement.
