If you’ve been lifting weights for any period of time, then you have no doubt heard about the benefits of creatine supplementation from your gym buddies or in bodybuilding magazines. For some people, anecdotal evidence of increased strength, greater workout intensities, and enhanced muscle size is enough to take the creatine plunge, but maybe you want more definitive proof.
Specifically, what do scientific studies really say about creatine use?
The good news is that there has been plenty of scientific research conducted on the efficacy and safety of creatine supplementation over the last two decades, and the results are readily available and generally add support to the purported benefits of this powerhouse amino acid.
Several studies have focused on the effects that creatine has on body composition, muscle strength, and training intensities.
In 1999, for example, J.S. Volek and his colleagues designed a double-blind, test-control experiment to examine the benefits of creatine supplementation in comparison to a placebo. During the study, 10 subjects were given daily doses of creatine, while a control group of nine subjects was given an equal amount of a placebo. Both groups consisted of healthy, athletic men who then engaged in the same weight training protocol over the course of 12 weeks.
At the end of the study, the creatine users had gained more than twice as much lean muscle tissue as the placebo users, with strength gains to match. In particular, the creatine group gained 24% on their top-end bench press numbers and 32% on their squats, as compared to just 16% and 24%, respectively, for the placebo group.
These types of results have been repeated by other researchers over the years, and, in 2003, RB Kreider conducted a survey of related studies. Examining the results of more than 500 peer-reviewed journal papers, Kreider found that over 70% of the scientists reported statistically significant benefits from creatine supplementation.
Of the 300 studies that specifically targeted ergogenic effects, typical strength increases were on the order or 5-15%, and overall per-set workloads increased by the same amount. Gains in lean mass were also experienced by the subjects in the majority of these studies.
Although science seems to support the idea that creatine can be an aid to exercise performance and may enhance body composition, what do researchers think about potential side effects?
In 2000, JR Poortmans and M. Francaux reviewed available creatine literature and found mostly anecdotal evidence of several adverse effects that some users have experienced, including muscle cramps, gastrointestinal distress, and dehydration. Beyond these self-reported symptoms, though, Poortmans and Francaux note that they did not turn up hard data to indicate any meaningful, widespread adverse effects from creatine supplementation
The reviewers did suggest, however, that introducing large amounts of creatine into your normal diet is a significant enough change to warrant consulting a physician and monitoring various health markers through regular blood tests.
This is great advice that you should ALWAYS follow whenever you make any changes to your diet, training, or supplementation schedule.
Most of the studies on creatine mentioned above spanned relatively short periods, say 10-12 weeks, since their main focus was on probing its effectiveness as an ergogenic aid to weight-training programs. What about the long term, though? Does science have concerns about creatine usage over a number of months or years?
DL Mayhew and his colleagues set out to answer that question in 2002 when they studied a group of 23 NCAA Division II football players who ingested creatine consistently for anywhere from three months to nearly six years. Blood markers of kidney and liver health were monitored for the duration of the study, and the researchers found no indication of any functionality loss.
Similarly, A. Bender and colleagues found no significant side effects apart from gastrointestinal distress in a study that spanned two years. While Bender’s research did not address ergogenic effects in any real way, it is perhaps an even better indication of creatine’s long-term safety than the Mayhew study when you consider that the subjects in this case were elderly Parkinson’s patients.
Even in older users with compromised health, Bender found no loss of kidney function due to creatine supplementation.
When you look at the entire body of scientific work related to creatine usage, it seems to support what gym rats have known for a couple of decades: creatine works, and is safe, for most people.
However, while the majority of research studies point to creatine as an effective supplement with few side effects for athletes looking to improve body composition and workout performance, the state of science is always in flux. So ask your doctor if you have any concerns about taking creatine, and then enjoy the benefits of more muscle and bigger weights.