Effect of creatine loading on anaerobic performance and skeletal muscle volume in NCAA Division I athletes.
OBJECTIVE
We measured the effect of 3 d of creatine (Cr) supplementation on repeated sprint performance and thigh muscle volume in elite power athletes.


METHODS
Ten male (mean +/- standard deviation of body mass and percentage of fat (81.1 +/- 10.5 kg and 9.8 +/- 3.5) and ten female (58.4 +/- 5.3 kg and 15.0 +/- 3.4) athletes were matched for sex and 10-s cycle sprint scores, paired by rank, and randomly assigned to the Cr or placebo (P) group. Subjects completed six maximal 10-s cycle sprints interspersed with 60 s of recovery before and after 3 d of Cr (0.35 g/kg of fat-free mass) or P (maltodextrin) ingestion. Before and after supplementation, 10 contiguous transaxial images of both thighs were obtained with magnetic resonance imaging.


RESULTS
Cr supplementation resulted in statistically significant increases in body mass (0.9 +/- 0.1 kg, P < 0.03), total work during the first sprint (P < 0.04), and peak power during sprints 2 to 6 (P < 0.10). As expected, total work and peak power values for males were greater than those for their female counterparts during the initial sprint (P < 0.02); however, the reverse was true during the last three sprints (P < 0.01). Imaging data showed a 6.6% increase in thigh volume in five of six Cr subjects (P = 0.05).


CONCLUSIONS
These data indicate that 3 d of Cr supplementation can increase thigh muscle volume and may enhance cycle sprint performance in elite power athletes; moreover, this effect is greater in females as sprints are repeated.
Ziegenfuss
Tim N
TN
Human Nutrition Research Laboratory, Kent State University, Kent, Ohio 44242, USA. tzphd@hotmail.com
Rogers
Michael
M
Lowery
Lonnie
L
Mullins
Nicole
N
Mendel
Ronald
R
Antonio
Jose
J
Lemon
Peter
P
D000284:Administration, Oral; D000328:Adult; D000693:Anaerobiosis; D003401:Creatine / Q000008:administration & dosage* / Q000494:pharmacology; D019587:Dietary Supplements; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D010919:Placebos; D012727:Sex Characteristics; D013848:Thigh
D010919:Placebos; D003401:Creatine