II. Epidemiology

  1. Not banned by IOC or NCAA
  2. Not detected by testing

III. 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

IV. Sources

  1. Synthesized by Liver, Kidney, Pancreas
  2. Exogenous dietary sources (Red meat or fish)
    1. Typical U.S. dietary intake: 1-2 grams per day
  3. Creatine Monohydrate
    1. Creatine Supplement Typical Use by power sport athletes
    2. Loading: 5 grams four times daily for 5 to 7 days
    3. Maintenance: 5 grams per day

V. 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 (e.g. bench press, squat)
      3. Rowing
      4. Jumping
    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 [PubMed]

VI. Adverse Effects

  1. Gastrointestinal upset
  2. Muscle cramps
  3. Weight gain (short-term, <1 week following intake)
    1. Associated with water retention
  4. Serum Creatinine increased (transient after starting)
  5. Renal Failure in patient with Nephrotic Syndrome
    1. No renal effects in later study of healthy men
  6. Anecdotal reports of assorted conditions reported
  7. Adverse effects beyond 3 months has not been studied

VII. Safety

  1. Avoid in pregnancy and Lactation (unknown safety)
  2. Probably safe in other healthy adults at typical dosing (see sources above)

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