Can creatine help you build muscle?

Usually, when it comes to ergogenic supplements, most health professionals will dissuade athletes from taking them citing lack of research, questionable safety, unwanted side effects. For this reason, it surprised me to read about creatine. Turns out that creatine is one of the best researched ergogenic aids on the market, was called by one well-known sport dietitian as "the most important natural fuel-enhancing supplement yet to be discovered for strength trainers" and can produce significant improvement in sports requiring high levels of power and strength.

What is creatine?

Creatine is a compound naturally found in meat and fish. We also synthesize it in our liver and kidney from amino acids. 95% of creatine is stored in our muscles where it becomes creatine phosphate, the primary fuel for short, high-intensity bursts of activity lasting 1-10 seconds like weight lifting, sprinting, ice hockey etc.
Just like endurance athletes carb-load to increase muscle glycogen stores, creatine-loading can increase muscle creatine stores. Creatine won't build muscle directly but will allow you to increase the duration and intensity of your workout, resulting in muscle gain.

How much?

We get about 1-2 g creatine from food daily (vegetarians get less) but supposedly that's not enough to improve strength training performance. Creatine supplements usually come in the form of powder under the name creatine monohydrate. Studies show that taking four to five 5 gram (1 tsp) doses a day for 5 days- or 0.3g/kg body weight per day- will result in rapid loading. From there, 2 grams (1/2 tsp) a day will keep muscles saturated. A more gentle loading regimen is 2 grams a day for 28 days. Taking more than 40grams daily may cause possible liver and kidney damage. .

Creatine stays in the muscles for 4-5 weeks after a loading phase without extra supplementation. Coordinate creatine supplementation with your training schedule, starting just before you begin a high intensity training session.

20-30% of people don't respond to creatine-loading. Interestingly, creatine works best in combination with a liquid carbohydrate supplement and this may help non-responders to get creatine into their muscles. Ingesting 75-100 grams carbohydrates can boost the amount of creatine loaded in muscles by up to 60%.
75 grams carbohydrate = 3 cups orange juice or 5 cups gatorade.

Side Effects

Creatine is non-toxic and so far there is no evidence to suggest that it's unsafe when taken by healthy adults in the recommended doses for a short term period of ~8 weeks (safety of prolonged use has not been determined yet). Nonetheless, the American College of Sports Medicine recommends that all athletes check with their doctor before taking creatine.

Creatine supplementation is not advised for people with pre-existing kidney disease. There's also no research done on the effect of creatine supplementation on growing kids under the age of 18.

Weight gain of 2-5 lbs is commonly seen in creatine users and is partly due to water weight but evidence now shows that much of the weight gain is a result of increased muscle mass. Anecdotal reports suggest that creatine may cause cramping, nausea, GI problems and higher rates of muscle tearing. The cramping may be the result of dehydration therefore it's recommended that athletes supplementing with creatine drink more water than usual.

As with any supplement, quality of the product is poorly controlled- what you buy is not necessarily what you get.

Creatine and Endurance

Creatine supplementation has been shown to have no effect on VO2max or to improve endurance. However, some researchers believe that creatine supplementation can indirectly improve endurance performance by lifting the lactate threshhold, allowing a more intensive interval-type training. Moreover, increasing muscle mass can potentially help certain endurance athletes like swimmer and rowers... but may hinder others that don't want extra muscle mass, like marathoners and long-distance cyclists.

Is it Legal?

Yes. Creatine actually became public when it was reported that Linford Christie, 100m gold-medal winner, used creatine during the 1992 Barcelona Olympics. Sally Gunnell, 400m hurdle gold-medalist and many British rowers used creatine in preparation for the Barcelona games as well. However, there is concern for cross-contamination since athletes taking creatine have tested positive for banned prohormone products.
The NCAA does not condone the use of creatine.

Sources

Kleiner SM, Greenwood-Robinson M. Power Eating: Build muscle, boost energy, cut fat, 2nd ed. Human Kinetics. 2001.

Ryan, M. Sports Nutrition for Endurance Athletes, 2nd ed. VeloPress 2007.

Girard-Eberle S. Endurance Sports Nutrition. Human Kinetics 2000.

Clark N. Sports Nutrition Guidebook, 3rd ed. Human Kinetics 2003.

Creatine supplements. http://en.wikipedia.org/wiki/Creatine_supplements