Eur J Appl Physiol. 2003 Dec 18 [Epub ahead of print]. Related Articles,
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The effects of creatine supplementation on muscular performance and
body composition responses to short-term resistance training
overreaching.

Volek JS, Ratamess NA, Rubin MR, Gomez AL, French DN, McGuigan MM,
Scheett TP, Sharman MJ, Hakkinen K, Kraemer WJ.

Human Performance Laboratory, Department of Kinesiology, University
of Connecticut, CT 06269, Storrs, USA.

To determine the effects of creatine supplementation during
short-term resistance training overreaching on performance, body
composition, and resting hormone concentrations, 17 men were randomly
assigned to supplement with 0.3 g/kg per day of creatine monohydrate
(CrM: n=9) or placebo (P: n= while performing resistance exercise (5
days/week for 4 weeks) followed by a 2-week taper phase. Maximal squat
and bench press and explosive power in the bench press were reduced
during the initial weeks of training in P but not CrM. Explosive power
in the bench press, body mass, and lean body mass (LBM) in the legs were
augmented to a greater extent in CrM ( P</=0.05) by the end of the
6-week period. A tendency for greater 1-RM squat improvement ( P=0.09)
was also observed in CrM. Total testosterone (TT) and the free androgen
index (TT/SHBG) decreased in CrM and P, reaching a nadir at week 3,
whereas sex hormone binding globulin (SHBG) responded in an opposite
direction. Cortisol significantly increased after week 1 in CrM (+29%),
and returned to baseline at week 2. Insulin was significantly depressed
at week 1 (-24%) and drifted back toward baseline during weeks 2-4.
Growth hormone and IGF-I levels were not affected. Therefore, some
measures of muscular performance and body composition are enhanced to a
greater extent following the rebound phase of short-term resistance
training overreaching with creatine supplementation and these changes
are not related to changes in circulating hormone concentrations
obtained in the resting, postabsorptive state. In addition, creatine
supplementation appears to be effective for maintaining muscular
performance during the initial phase of high-volume resistance training
overreaching that otherwise results in small performance decrements.

PMID: 14685870 [PubMed - as supplied by publisher]