Creatine is actually formed endogenously in the body by the liver, kidney, and pancreas. It is used as energy for the muscles. Creatine can be found in food such as meat, fish, and eggs. People who eat mostly plant-based diets may have reduced stores of creatine in their bodies. Creatine is often used as an ergogenic aid with the purpose of increasing lean muscle mass, increase strength, and reduce the time needed for recovery. In the past, I have heard horror stories about the side effects of creatine supplements so I have avoided them all together. However, I realized I never really had any evidence to back up my fear of creatine.
Today I’m going to look at an article published in the Journal of International Sports Nutrition about creatine supplementation specifically in relation to exercise and sports. The article was able to find that creatine does, in fact, have a positive effect on strength and hypertrophy with resistive exercise. Creatine also had an effect on lowering the lactate levels in the blood and increasing the lactate threshold. The lactate threshold is reached when the amount of lactate in the blood is increasing faster than it can be taken out. Once reaching lactate threshold your body will need to rest so that it can build up ATP stores again to prepare for the next lift. Increased creatine stores in the body, allows for increased rates of ATP synthesis, intern reducing the rest time required between lifts. In terms of recovery, creatine reduced the level of delayed onset muscle soreness and was a useful antioxidant post workout. They noted that creatine is best used for anaerobic exercise and the effect decreases as the length of the workout increases. Due to this creatine is less useful for endurance exercise.
The authors also looked at different dosing schedules and found that in order to get the most gains it is useful, to begin with a loading period of about 20g per day and follow this with maintenance doses of 3-5g per day. The article reported that there were no short-term effects on liver or kidney function. However, there has yet to research done on the long-term effects of creatine. It was found that with the use of a creatine supplementation the bodies endogenous formation of creatine decreases. But, shortly after ceasing supplementation endogenous formation picked back up again.
Overall, the article found that creatine is most effective when used for supplementing resistance or anaerobic workouts. People who have decreased levels of endogenous creatine and people with higher amounts of type II muscle fibers will see the most results from creatine supplements. There are no short-term negative effects, but there has yet to be studies about the long-term effects.
Cooper, R., Naclerio, F., Allgrove, J., & Jimenez, A. (2012). Creatine supplementation with specific view to exercise/sports performance: an update. Journal of the International Society of Sports Nutrition, 9, 33. http://doi.org/10.1186/1550-2783-9-33