Written by Greg Arnold, DC, CSCS. In a small study of young healthy men and women it was found that fatigue was reduced by 7-11% in multiple maximum knee extensions.
Creatine is a naturally occurring compound synthesized from the amino acids arginine, glycine, and methionine. It is found in meat and fish and can be synthesized by humans in the liver and pancreas.
Creatine’s ability to increase strength by helping maintain levels of the body’s energy unit (called ATP) (1) has resulted in as much as 75% of athletes having reported using creatine to help both athletic performance and recovery (2). Now a new study (2) has found that creatine may help with fatigue even in the absence of weight gain.
In the study, 20 healthy men and women with an average age of 21 years were given either creatine (30 mg per kg of bodyweight = about 2.3 grams per day average of the patients) or placebo for 6 weeks. During this time, they were weighed and had their body fat tested. They also provided blood samples and performed strength tests to measure for both maximal strength and muscle fatigue. The maximal strength test consisted of a 3-repetition maximal knee extension test, while muscle fatigue was measured with 5 sets of 30 knee extensions.
The researchers found that while there were no significant differences between the 2 groups in body mass, fat-free mass, fat mass, body fat percentage, total body water, or maximal strength at the end of the study, those in the creatine group demonstrated greater resistance to fatigue. Specifically, compared with the fatigue tests before the study, those in the creatine group had more patients who were more resistant to fatigue (thereby performing more repetitions) during sets 2 (7%), 3 (9%), 4 (9%), and 5 (11%) while those in the placebo group had no improvement in fatigue resistance during sets 2 (0%), 3 (1%), 4 (0%), and 5 (1%). When they looked at blood levels of creatine, those in the creatine group had a 182% increase while no increase was seen in the placebo group.
For the researchers, “Ingesting a low dose (about 2.3 grams/day) of creatine for 6 weeks significantly increased [blood levels of creatine] and enhanced resistance to fatigue during repeated bouts of high-intensity contractions.” When it comes to creatine dosing, there are currently two different approaches. In the first method, a “loading” dose of creatine, usually about 20 to 25 g/d (300 mg per kg of bodyweight per day), for 5 to 7 days is ingested followed by the 30 mg/kg/day. In the second method, there is no “loading phase” but instead just the lower doses of creatine, usually about 2 to 5 grams per day (5).
Source: Rawson, Eric S., et al. “Low-dose creatine supplementation enhances fatigue resistance in the absence of weight gain.” Nutrition 27.4 (2011): 451-455.
© 2011 Elsevier Inc. Published by Elsevier Inc
Posted August 9, 2010.
References:
- Casey A. Does dietary creatine supplementation play a role in skeletal muscle metabolism and performance? American Journal of Clinical Nutrition 2000; 72: 607S ? 617.
- Rawson ES, et al., Low-dose creatine supplementation enhances fatigue resistance in the absence of weight gain, Nutrition (2010), doi:10.1016/j.nut.2010.0 4.0 01.
- Fuld JP. Creatine supplementation during pulmonary rehabilitation in chronic obstructive pulmonary disease. Thorax 2006;60(7): 531-537.
- Kley R. Creatine for treating muscle disorders.> Cochrane Database Syst Rev. 2007 Jan 24;(1):CD004760.
- Hultman E, So ¨ derlund K, Timmons JA, Cederblad G, Greenhaff PL. Muscle creatine loading in men. J Appl Physiol 1996;81:232?7.
