To CREATINE or not to CREATINE

Ilana Katz, MS, RD, LD

An ergogenic aid is a substance that enhances a person's athletic ability, either through improvements in power or enhanced endurance. Creatine has surfaced as an ergogenic aid that physically active people are willing to take. It is a nitrogenous substance found in meat and synthesized in the body from three amino acids. It is considered ergogenic because it combines quickly with phosphate to form phosphocreatine, which is a high-energy compound stored in muscle.

It is therefore believed that saturating muscles with creatine will enhance the ability to hold on to that high energy compound and thus delay fatigue in high intensity activity. Creatine is naturally synthesized in the liver by the amino acids arginine, glycine, and methionine, all of which are readily available through animal-based sources of protein (eggs, meat, chicken, fish). Unfortunately cooking reduces the level of creatine in food and thus the bioavailability of dietary creatine remains small, especially because raw meat is unsafe.

The commercially synthesized supplementation of creatine, in the form of Creatine Monohydrate has been researched fairly extensively. There is evidence of an increase in lean body mass within 6 days of ingestion (at 25 grams/day). Many athletes are therefore taking daily creatine supplements, and furthermore, it has become freely available as a sports nutrition supplement for the average Joe, wishing to enhance regular work outs in the neighborhood gym.

However, there are considerations when making the decision whether to use creatine as an ergogenic aid or not. Firstly, it is not clear whether the increase in lean mass evident in recent studies, is due to a greater production of muscle proteins or due to the more likely water retention in muscles. There is evidence that creatine storage in muscle causes the aforementioned water retention and thus an associated weight gain.

Furthermore, an inadequate caloric intake is a common problem among athletes, and the benefit derived from creatine may be due to meeting daily requirements of the appropriate amino acids through supplementation. Athletes who manage to meet caloric demands are less likely to gain the ergogenic benefit from creatine.

Muscle creatine saturation has been shown to increase the risk of liver or kidney damage. There is evidence that muscle creatine reaches a saturation point after approximately five days. Dosing issues surrounding creatine is thus important to consider in order to reduce the risk of organ damage. Creatine supplements should therefore not be taken for more than five continuous days. Furthermore, at least a five day break before resumption is recommended. Some research has shown that as little as five days per month of the supplement in the correct dosage is adequate to saturate the muscle. A daily dose ranges between 10 and 28 grams based the individual's size. The daily dosage should be divided into four doses per day; in other words, if the athlete is taking 10 grams per day, he should be consuming 2.5 grams 4 times equally spaced throughout the day. (The smaller the athlete, the smaller the dosage should be).

Although there is currently no definitive evidence to suggest that creatine supplementation is unsafe, long term safety of creatine monohydrate testing is limited. The point is that although creatine has the potential to be an ergogenic aid, caution about the supplement is recommended until long term effects are known. If the decision to take creatine is affirmative, dosing should be carefully monitored. A reasonable approach would be to consume sufficient energy and include good sources of protein and creatine in such foods as meat, chicken and fish.