Creatine

1. Epidemiology
   1. Not banned by IOC or NCAA
   2. Not detected by testing
2. Physiology
   1. High energy cells (skeletal muscle) use Creatine
   2. Creatine acts as phosphate donor to form ATP
   3. Muscle stores enough for 10 seconds high intensity
3. Sources
   1. Synthesized by Liver, Kidney, Pancreas
   2. Exogenous dietary sources (Meat or fish)
      1. Typical U.S. dietary intake: 1-2 grams per day
   3. Creatine Supplement Typical Use by power sport athletes
      1. Loading: 5 grams four times daily for 5 to 7 days
      2. Maintenance: 5 grams per day
4. Efficacy
   1. Mixed results from randomized trials
   2. Studies find strength and mass increase (men and women)
      1. Beneficial in high intensity sports (bursts of activity <30 seconds)
         1. Football
         2. Weight lifting
      2. Variable effect in sprinters
         1. Endurance time improved in the lab
         2. Benefit not found in field performance
      3. Not effective in endurance sports
         1. No effect in Running and swimming
      4. References
         1. Branch (2003) Int J Sport Nutr Exerc Metab 13(2): 198-226
5. Adverse Effects
   1. Weight gain (short-term, <1 week following intake)
   2. Probably safe
   3. Renal Failure in patient with Nephrotic Syndrome
      1. No renal effects in later study of healthy men
   4. Anecdotal reports of assorted conditions reported
   5. Adverse effects beyond 3 months has not been studied
6. References
   1. (1998) Med Lett Drugs Ther 40(1039): 105
   2. (2001) Am Fam Physician 63(5):913-22