Creatine – the controversial muscle powder
Creatine, which is used as a body building and training supplement, builds myths as well as muscles – so what are the facts?
Creatine is a substance that our bodies produce naturally from amino acids.
Creatine bonds with phosphates to make creatine phosphate molecules in muscle cells and serves as a rapidly accesible source of high energy.
Many of us associate creatine with sporting goods stores and locker rooms rather than biochemistry labs. Creatine is marketed in powdered form as a so-called sports supplement.
If you look up creatine on the Web you come across countless threads on whether it works, which brands you should buy and above all – what side effects it can have.
Not for everyone
Creatine monohydrate, the most common form of creatine supplement, essentially has two effects on athletes.
It can increase energy capacity during short, maximal training sessions such as sets of strength-building exercises or short, repeated spurts. It can also help atheletes build bigger muscles during strength training.
Professor Truls Raastad of the Norwegian School of Sport Sciences has prepared a report for the Norwegian Scientific Committee for Food Safety, on commission from the Norwegian Food Safety Authority. His study evaluates the effects and possible risks of creatine supplements.
He confirms that creatine supplements can be quite effective. But not everyone can benefit from an extra intake of creatine.
“We should bear in mind that about 30 percent of those who try a creatine supplement will see little effect. This is most likely because their body’s store of creatine phosphate is already sufficient. Their diet and exercise have already provided the maximum amount of creatine their muscles can store,” he says.
A normal diet provides around one gram of creatine per day. Common sources are fish and red meat.
How does it work?
Nearly all the creatine in the body is stored in skeletal muscles as creatine phosphate.
Muscles can use creatine phosphate for a rapid energy boost when the demand is great and muscle cells are fully supplied with the substance.
Adenosine triphosphate, or ATP, is the compound your body uses for energy. A muscle breaks off a phosphate molecule from ATP when it contracts. As a result, ATP becomes ADP (adenosine diphosphate).
You can’t use ADP for energy, and your body only has so much stored ATP. The fix is when ADP takes a phosphate molecule from your body’s stores of creatine phosphate and forms more ATP.
This effect is rather short-lasting because the supplies in cells are quickly depleted, thus causing fatigue and limiting athletic performance.
Theoretically, however, if a person fills up his or her creatine phosphate storehouses with supplements, the effect will last longer.
This effect is experienced most by people who opt for short, maximum sets of exercises, which are repeated at short intervals.
Creatine is an osmotically active substance; it pulls water into muscle cells.
“One of the things that happens when you take creatine is that your muscle cells will begin to absorb more water and swell up. This stimulates the cells to grow more than they would have without the additional creatine, at least during the start of a training period,” explains Raastad.
People who use creatine supplements are recommended to first fill up their body's 'stockpile' with about 10-20 grams daily for a week, then maintain that level with an intake of 2-5 grams per day for a few weeks.
Little research has been done on the long-term effect of creatine supplements.
Who should use creatine?
Some 12 percent of male top athletes and two percent of female athletes used creatine supplement, according to Raastad's report. These athletes were compared to a control group from the general population, in which three percent of men and no women used creatine.
“Creatine supplements are best suited to athletes who need strength, explosive bursts of energy and large muscle mass, such as ice hockey players or weightlifters. It can pay off in lots of sports that require masses of muscle,” says Raastad.
Even people who don’t train at a top athletic level can reap its benefits.
“You will encounter a rapid change, including a sudden weight gain, as the cells absorb more water. But I would advise people to be a little more patient. How happy will that weight gain make you in the long run?” Raastad asks.
Certain studies have also shown that creatine supplements can benefit patients who have lost muscle mass as a result of disease.
Side effects and assorted brands
Many claim that creatine can have a number of side effects and can be potentially dangerous, affecting the kidneys and causing gastrointestinal problems and cramps.
The market is thus teeming with patented creatine supplements whose manufacturers claim to have eliminated the side effects caused by competitors’ products.
But most of these side effects are described in non-scientific publications.
“It’s not unreasonable to think the claims of side effects come from producers who are consciously trying to undermine other brands and position their own in the market,” says Raastad.
He found no proven health hazards among the creatine supplements he worked with in his scientific report for the Norwegian health authorities.
On the other hand, the producers of a newly patented creatine brand, Kre-Alkalyn, claim its particular compound works better without side effects. But one study appears to undermine these claims.
Test subjects who were strength training used Kre-Alkalyn or a common creatine supplement and scientists monitored their performance results for 28 days.
The results showed no difference between the two supplements and none of the test subjects reported any side effects.
Read the Norwegian version of this article at forskning.no
Translated by: Glenn Ostling
- Frølich, W., Børsheim, E., Raastad, T. Assessment of creatine in sports products. Vitenskapskomiteen for mattrygghet (2010)
- Jagim, A. R., Oliver. et. al. Buffered form of creatine does not promote greater changes in muscle creatine content, body composition, or training adaptations than creatine monohydrate Journal of the International Society of Sports Nutrition (2012)