Creatine for Sports Performance and Fitness
Dru C. Smith, DPT, RPT, RD

In the world of sports and athletic performance, we are always looking to gain that extra edge. With that, we want to make sure that first of all that “edge” is truly effective, secondly we want to know it is safe. One of the most popular means used to achieve this edge today is nutritional supplements. First off, we need to understand the function a supplement is meant to perform. The purpose of a supplement is to improve upon or complete the whole. Implying that the supplement will not be affective without the other parts of the whole already in place (i.e.: proper diet and training).

Of these sports supplements, creatine is no doubt one of the most common and believed to be one of the most effective (1). Creatine is a product naturally synthesized in small amounts, primarily in the liver and pancreas (2,3). Creatine can also be obtained in fair amounts by consuming meat and fish (2,3). The theorized benefit of creatine comes by looking at the root of human movement. This root is ATP (adenosine triphosphate), which is essentially the fuel for our bodies to move. ATP is made up of one molecule of adenosine and three molecules of phosphate. When this bond is broken, it indirectly results in a contraction of the muscle. This results in a single phosphate (Pi) and ADP (adenosine diphosphate), which is not a great source of energy for the muscle. Due to a limited supply of stored ATP in our body and ADP not being a good fuel source, we then must find a way for our body to quickly resynthesize the ATP in order to maintain a high intensity level of muscle contractions. In comes creatine (creatine phosphate), which can be quickly split to provide the extra phosphate to ADP in order to re-make ATP. Creatine phosphate is stored in the skeletal muscle alongside ATP at an amount equaling approximately three times that of ATP (4). Therefore creatine can serve as a quick and readily available source to provide more ATP to a working muscle (3). By understanding these principles, one could logically conclude that providing more creatine to our muscles would lead to increased availability of ATP, thus greater muscle performance during high intensity exercise (2).

Numerous studies on healthy young adults have shown that creatine supplementation significantly enhances muscle performance during short bursts of very high intensity exercise lasting ≤ 30 seconds (1,2,3,4,5,6). These test subjects have come from mixed athletic ability and training status, ranging from relatively untrained novices to very high level competitive athletes (3). The test criteria have also come from a broad range of exercises including: short term high intensity bouts of all-out cycling, sprinting, jumping, swimming, weight/resistance training, and skating (3,5). The best results have been found to occur when these short bouts occur in a series (separated by brief periods of rest) with the greatest gains occurring in that later bouts when compared to a placebo group (non-creatine supplemented) (3). Long term adaptations of combining training with creatine supplementation include: increased muscle creatine, lean body mass (muscle), strength, sprint performance, power, rate of force development, and muscle diameter (2). While the quick burst of lean body mass in the short term appears to be mainly water weight, the added gains in the long term is proposed to be a result of the body’s ability to perform at a higher intensity and for longer periods, thus resulting in actual increased muscle mass (2,6). Most studies have shown that creatine supplementation has little to no benefit on aerobic performance/endurance events (1,3,4). Although some research has shown that creatine supplementation can have a positive impact on power production during short sprints within and at the end of endurance events (3,6).

With many different forms of creatine and combinations available in the marketplace, most have been reported to be no better than the traditional creatine monohydrate for improving strength and performance (2,3). Multiple studies have found that the best and most agreed upon dosing method for creatine supplementation involves a 4-7 day “loading” period, followed by a daily “maintenance” dose (2,3,4,5). The loading phase is used to initially boost the creatine stores in the muscle with the dose most often used being 5 grams (approximately 1 teaspoon) taken 4-5 times per day with a total of 20-25 grams per day. The maintenance phase involves a daily dose of 2-5 grams and is used to maintain the increased level of muscle creatine provided by the loading phase (2,3,4,5). Creatine uptake into the muscle has also been shown to increase when combined a liquid carbohydrate solution such as juice or a carbohydrate containing sports drink (3,4). This leads to the question of when should the creatine supplement be taken? Creatine would best be taken within 30 minutes after a workout or training session, in which time the muscles are most receptive to the uptake of nutrients. I know what you’re thinking right now, “if this dose is good, more must be better”. Wrong idea and here’s why: the body essentially has a ceiling effect as to how much creatine can be stored into the muscle and will then simply excrete the excess out in the urine if more is taken (3,4).

With creatine only being widely available to the public since the early 1990’s, the verdict is still out on whether or not any side effects may result from long-term use. That said, no long-term side effects have been observed in athletes using creatine up to 5 years (2). While in short-term use, creatine supplementation has been linked to such side-effects as diarrhea, dehydration, muscle cramping, muscle strains, and cardiovascular problems these side effects have been refuted by many studies (2). It is though still believed that creatine supplementation may be detrimental to individuals with pre-existing kidney disease, thus these individuals should not supplement with creatine or be closely monitored medically (3,5). When looking at creatine supplementation for children, it is viewed that the child/athlete should be past puberty, approved and supervised by parents, eating an adequate diet, training at a level that may benefit from creatine supplementation, and not exceed recommended dosages (2). It is still advised that if any concerns remain, you should consult with your physician before beginning creatine supplementation.

References:

1. American College of Sports Medicine, American Dietetic Association, Dietitians of Canada. Nutrition and Athletic Performance. Medicine & Science in Sports & Exercise. 2009; 41(3):709-731

2. Buford TW, Kreider RB, Stout JR, et al. International Society of Sports Nutrition position: creatine supplementation and exercise. Journal of the International Society of Sports Nutrition. 2007; 4:6

3. American College of Sports Medicine. The physiological and health effects of oral creatine supplementation. Medicine & Science in Sports & Exercise. 2000; 32(3):706-717

4. Warpeha JM, Creatine Explained. NSCA’s Performance Training Journal. 2006; 5(1): 6-8

5. Kleiner SM, Greenwood-Robinson M. Power Eating. 2^nd Ed. Champaign, IL. Human Kinetics. 2001

6. Branch JD, Effect of Creatine Supplementation on Body Composition and Performance: A Meta-analysis. International Journal of Sport Nutrition and Exercise Metabolism. 2003; 19: 198-226

7. Engelhardt M, Neumann G, Berbalk A, et al. Creatine supplementation in endurance sports. Medicine & Science in Sports & Exercise. 1998; 30: 1123-1129