Creatine is the most researched athletic performance supplement on the market to date - it is also touted as the most controversial. We can be sure that creatine will remain at the forefront of sports supplementation, so how exactly does creatine supplementation work and what are the benefits?
The Phosphocreatine Energy System
During maximal exercise, working skeletal muscle uses phosphocreatine to produce ATP quickly. The enzyme creatine kinase breaks down phosphocreatine, or PCr, to create ATP. The idea behind creatine supplementation is to provide skeletal muscle with enough creatine to max out the PCr stored in the muscle. This would provide the optimal amount of PCr available for ATP production during short bursts of high intensity exercise.
ATP + Creatine ← creatine kinase → ADP + PCr + H+
The Performance Benefits of Creatine Supplementation
Creatine has been shown to increase athletic performance in very high intensity exercise, such as sprints or jumps - anything that requires power in the short term. This benefit seems to not only be due to the greater amount of PCr available, but also because of the ability of creatine to shorten the relaxation time of muscle during contraction.
Although many athletes opt for creatine “loading” in which the ingest 20-30g/day for 5-7 days, similar performance benefits have also been seen at a more moderate intake of 3g/day over several weeks.
Creatine supplementation is likely to benefit vegetarian/vegan athletes the most, as they are most likely to have the least amount of skeletal muscle PCr stored.
Caffeine may counteract the benefit of creatine supplementation, as it can prolong muscle relaxation time.
Different Types of Creatine Supplements
There are several different types of creatine including creatine monohydrate, creatine + HMB, creatine ethyl ester, creatine + glycerol, etc. At this point in time, no one form of creatine supplementation has been shown to be significantly superior to another in that it provides greater improvements in athletic performance, however, more research is needed to determine this with certainty.
There are several natural food sources of creatine as well.
- Milk - 0.1g/kg
- Tuna - 4.0g/kg
- Beef - 4.5g/kg
- Pork - 5.0g/kg
Myths of Creatine Supplementation
Creatine Supplementation Causes Kidney Destress
There is not evidence that reasonable creatine supplementation of <25g/day causes renal distress in the short, medium, or long term (up to five years). Over supplementation has not been well reviewed, but as a general rule, too much of anything is not good.
Creatine Causes Dehydration
Dehydration should not be a major concern either. Be diligent to stay hydrated, especially when exercising in the heat, primarily to prevent muscle cramps.
Overdosing and Contaminants are a Major Concern
Overdosing does not appear to be a concern at low supplementation at 5g/day. Some creatine may contain contaminants such as ephedrine, so it IS important to make sure your creatine has been reviewed and verified as safe. (USP and NSF International are both good third party organizations to look for on supplements to know they have been checked and verified.)
All Weight Gained through Creatine Supplementation is Water Weight
Some of the weight gained while supplementing with creatine probably is water, but probably not all of it - creatine supplementation has been linked with increased lean muscle mass as long as the taker is appropriately performing resistance training alongside.
Take-Aways
This is a review of research, NOT a recommendation to take creatine as a supplement. Make sure it is safe for you personally to supplement before you do so.
Creatine supplementation may boost performance in very high intensity, short term exercise.