Athletes often supplement their diets with creatine, which is a naturally occurring amino acid found in the human body, to improve performance and enhance muscle building. Most studies that have tested creatine start with a loading phase in which higher doses are taken, followed by a maintenance phase, which consists of lower doses.
Uses for Creatine
Creatine may be most effective in increasing lean muscle mass and in improving strength, making it a supplement of choice among weightlifters, bodybuilders and other athletes who engage in resistance exercise. The University of Maryland Medical Center, however, notes that creatine does not seem to improve performance in endurance exercises, such as running. Creatine may help with weightlifting, sprinting and other anaerobic exercises by increasing adenosine triphosphate -- which is an energy-carrying molecule that can fuel muscles as well as other cellular processes.
General Recommendations and Duration
The New York University Langone Medical Center notes that creatine is typically used beginning with a loading phase of 15 to 30 grams per day, for three to four days. You should divide this dosage into two or three separate servings. After the loading phase, you can take between 2 and 5 grams of creatine per day. While a study published in 2009 in the "Clinical Journal of Sport Medicine" concluded that long-term clinical safety cannot be guaranteed, another study published in 2003 in "Molecular and Cellular Biochemistry" found that 21 months of creatine supplementation did not have any adverse effects on intensely trained athletes, when compared to those who did not receive creatine.
Doses and Methods Used in Research Studies
The study published in 2009 in the "Clinical Journal of Sport Medicine" administered 25 grams of creatine with 25 grams of glucose per day to college rugby players for a seven-day period. This was followed by a 14-day maintenance period of 5 grams per day, taken with 25 grams of glucose. Consuming creatine with carbohydrates, such as glucose, may improve creatine absorption, according to the University of Maryland Medical Center. The medical center recommends that you take creatine with fruit, fruit juices or other starches. Another study published in 2001 in "Nutrition" administered 20 grams of creatine for seven days, followed by 10 grams for 14 days. This regimen also helped increase muscle mass in participants.
The University of Maryland Medical Center notes that while creatine appears to be safe, higher doses can potentially cause serious side effects, including kidney damage. In addition, taking creatine with nonsteroidal anti-inflammatory drugs, such as ibuprofen, can increase this risk. Side effects of creatine can include weight gain, muscle cramps, upset stomach, dizziness, high blood pressure, muscle strains and liver dysfunction. Children and teens should not use creatine.