Effect of creatine supplementation on training for competition in elite swimmers.
OBJECTIVE
The study was conducted to examine the effects of oral creatine supplementation on training for competition in 20 elite swimmers.


METHODS
Subjects performed a maximal sprint test (8 x 50 yd (45.72 m), T1) before loading with creatine (Cr, 20 g.d Cr monohydrate for 5 d), 1 wk later (T2), and following a 22- to 27-wk period of training and competition (T3). Following T2, subjects supplemented with either Cr (3 g + glucose 7 g.d) or placebo (glucose 10 g.d; double blind) for the remainder of the 22- to 27-wk season and then both groups supplemented once more with 20 g.d Cr monohydrate for 5 d before their major competition. Venous and capillary blood samples were obtained pre- and posttest during the repeated sprint tests to determine blood metabolites and hormones. Competition times were recorded, and changes in subjects' best times were used to compare the effect of training and supplementation on competitive performance.


RESULTS
Mean competition times in the Cr and control groups changed by+1.90 +/-1.91 and+0.72+/-1.64% for short course (SC, 25-m pool) and by+0.14+/-1.14 and -0.59+/-0.82% long course (LC, 50-m pool), respectively (Cr vs control, NS). No differences between groups were found in blood metabolites, although the human growth hormone (hGH) response to repeated sprints was blunted following Cr loading (T1, 30.42+/-14.60 and 28.95+/-18.27 microg.L; T2, 21.48+/-13.96 and 14.24+/-7.32 microg.L for Cr and control groups, respectively P<0.05).


CONCLUSIONS
No statistically significant differences in performance were observed between groups after long-term maintenance during training, although small differences were observed that might be meaningful for elite performers.
Peyrebrune
Michael C
MC
English Institute of Sport, EIS Pool, Loughborough University, Leicestershire, ENGLAND. mikeyp@tinyworld.co.uk
Stokes
Keith
K
Hall
George M
GM
Nevill
Mary E
ME
D000328:Adult; D016022:Case-Control Studies; D003163:Competitive Behavior; D003401:Creatine / Q000008:administration & dosage / Q000494:pharmacology*; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008297:Male; D010806:Physical Education and Training; D013550:Swimming / Q000502:physiology*; D013997:Time Factors
D003401:Creatine