CREATINE & ATHLETIC PERFORMANCE
WHAT IS CREATINE & HOW DOES CREATINE WORK
Creatine is one of the most extensively studied and widely used dietary supplements to enhance exercise and sports performance. Creatine is produced by the body and obtained from the diet in small amounts. It aids in generate ATP. In doing so creatine supplies the muscles with energy, particularly for short-term events. Creatine is thought to improve muscle performance in several ways: increasing stores of phosphocreatine used to generate ATP at the start of intense exercise, accelerating the re-synthesis of phosphocreatine after exercise, decreasing the degradation of adenine nucleotides and the accumulation of lactate, and/or boosting glycogen storage in skeletal muscles.
The body and in particular the liver and kidneys synthesize about 1 g/day creatine from the three amino acids glycine, arginine, and methionine. Animal-based foods, such as beef (2 g/lb), salmon (2 g/lb), and pork (2.3 g/lb), also contain creatine. A person weighing approximately 154 pounds would have roughly 120 g creatine and phosphocreatine in his or her body, with it predominantly being found in the skeletal and cardiac muscles. However, it is only when users consume much greater amounts of creatine over time as a dietary supplement that it could have performance effects. When is metabolized it is converted into the waste product creatinine, which is eliminated from the body through the kidneys.
HOW EFFECTIVE IS CREATINE
Several studies in both laboratory and sports settings have found that creatine supplementation (for 5 to 7 days) in both men and women significantly increases strength (e.g., for bench presses) and power (e.g., for cycling), work involving multiple sets of maximal effort muscle contractions, and sprinting and soccer performance. In the study by Volek JS, et al, it randomized 14 healthy, resistance-trained men (aged 19–29 years) who receive 25 g creatine monohydrate or a placebo for 6–7 days. Participants taking the supplement had significant improvements in peak power output during all five sets of jump squats and in repetitions during all five sets of bench presses on three occasions. Other studies resulted in significant improvement with performance after taking 20 g per day as compared to those that did not.
Supplementation with creatine over weeks or months helps training adaptations to structured, increased workloads over time.
With many supplements, an individual’s responses to creatine supplementation can vary largely based on factors such as diet and the percentages of various muscle fiber types. Vegetarians, as an example, may have lower muscle creatine content, and thus may have greater response to supplementation than meat eaters. Overall, creatine boosts performance during repeated short bursts of high-intensity, intermittent activity, such as sprinting and weight lifting. The primary reason is anaerobic exercise comes mainly from the ATP-creatine phosphate energy system.
SIDE EFFECTS OF CREATINE
For all intensive purpose, creatine is considered safe for short-term and long term use by healthy adults. Most individuals have no side-effects at all but there are some reports of nausea, diarrhea and related gastrointestinal distress, muscle cramps, and heat intolerance. Overuse with creatine supplementation may have the potential of reducing the range of motion of various parts of the body (such as the shoulders, ankles, and lower legs) and lead to muscle stiffness and resistance to stretching. This is one important reason to maintain adequate hydration while taking creatine and therefore minimize these uncommon risks.
EXPERTS SAY ABOUT CREATINE – AMERICAN COLLEGE OF SPORTS MEDICINE
The position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine is that creatine enhances performance of cycles of high-intensity exercise followed by short recovery periods and improves training capacity. In addition the International Society of Sports Nutrition states that creatine monohydrate is the most effective nutritional supplement currently available for enhancing capacity for high- intensity exercise and lean body mass during exercise. They also stipulate that athletes who supplement with creatine have a reduced incidence of injuries and exercise-related side effects compared to those who do not take creatine.
DOSE OF CREATINE
There are several different protocols for creatine intake with most being very similar. A standard protocol for creatine supplementation in adults, regardless of sex or body size, starts with a loading phase for 5–7 days, by consume 20g per day of creatine monohydrate in four portions of 5 g, followed by a maintenance phase of 3–5 g/day. Other recommend the loading dose be based on body weight (e.g., 0.3 g/kg). Another creatine supplementation protocol consists of taking one dose of about 3–6 g/day (0.03–0.1 g/kg body weight) for 3 to 4 weeks, eliminating a loading phase, to produce ergogenic effects.
BEST TYPE OF CREATINE
The most widely used and studied form is creatine monohydrate, which is 88% creatine by weight. Other, typically more expensive, forms of creatine (e.g., creatine ethyl ester, creatine alpha-ketoglutarate, and buffered forms of creatine) have not been proven to have superior ability to creatine monohydrate for enhancing muscle creatine levels, digestibility, product stability, or safety.