Effect of inosine supplementation on aerobic and anaerobic cycling performance.
Ten competitive male cyclists completed a Wingate Bike Test (WIN), a 30-min self-paced cycling performance bout (END), and a constant load, supramaximal cycling spring (SPN) to fatigue following 5 d of oral supplementation (5,000 mg.day-1) with inosine and placebo. Blood samples were obtained prior to and following both supplementation periods, and following each cycling test. Uric acid concentration was higher (P < 0.05) following supplementation with inosine versus placebo, but 2,3-DPG concentration was not changed. The data from WIN demonstrate that there were no significant differences in peak power (8.5 +/- 0.3 vs 8.4 +/- 0.3 W.kg body mass-1), end power (7.0 +/- 0.3 vs 6.9 +/- 0.2 W.kg body mass-1), fatigue index (18 +/- 2 vs 18 +/- 2%), total work completed (0.45 +/- 0.02 vs 0.45 +/- 0.02 kJ.kg body mass-1.30-s-1), and post-test lactate (12.2 +/- 0.5 vs 12.9 +/- 0.6 mmol.l-1) between the inosine and placebo trials, respectively. No difference was present in the total amount of work completed (6.1 +/- 0.3 vs 6.0 +/- 0.3 kJ.kg body mass-1) or post-test lactate (8.4 +/- 1.0 vs 9.9 +/- 1.3 mmol.l-1) during END between the inosine and placebo trials, respectively. Time to fatigue was longer (P < 0.05) during SPN for the placebo (109.7 +/- 5.6 s) versus the inosine (99.7 +/- 6.9 s) trial, but post-test lactate (14.8 +/- 0.7 vs 14.6 +/- 0.8 mmol.l-1) was not different between the treatments, respectively. These findings demonstrate that prolonged inosine supplementation does not appear to improve aerobic performance and short-term power production during cycling and may actually have an ergolytic effect under some test conditions.
Starling
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RD
Human Performance Laboratory, Ball State University, Muncie, IN 47306, USA.
Trappe
T A
TA
Short
K R
KR
Sheffield-Moore
M
M
Jozsi
A C
AC
Fink
W J
WJ
Costill
D L
DL
D019794:2,3-Diphosphoglycerate; D000328:Adult; D018592:Cross-Over Studies; D004163:Diphosphoglyceric Acids / Q000097:blood; D004311:Double-Blind Method; D005080:Exercise Test; D005527:Food, Fortified; D006339:Heart Rate; D006801:Humans; D007288:Inosine; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010101:Oxygen Consumption
D004163:Diphosphoglyceric Acids; D019794:2,3-Diphosphoglycerate; D019344:Lactic Acid; D007288:Inosine