Int J Sports Med 2003; 24(2): 144-150
DOI: 10.1055/s-2003-38400
Nutrition
2nd revision
© Georg Thieme Verlag Stuttgart · New York

Effects of Oral Creatine-Pyruvate Supplementation in Cycling Performance

R.  Van Schuylenbergh1 , M.  Van Leemputte1 , P.  Hespel1
  • 1Exercise Physiology and Biomechanics Laboratory, Department of Kinesiology, Faculty of Physical Education and Physiotherapy, Katholieke Universiteit Leuven, B-3001 Leuven, Belgium.
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Publication History



Accepted after revision: June 28, 2002

Publication Date:
01 April 2003 (online)

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Abstract

A double-blind study was performed to evaluate the effects of oral creatine-pyruvate administration on exercise performance in well-trained cyclists. Endurance and intermittent sprint performance were evaluated before (pretest) and after (posttest) one week of creatine-pyruvate intake (Crpyr, 2 × 3.5 g × d-1, n = 7) or placebo (PL, n = 7). Subjects first performed a 1-hour time trial during which the workload could be adjusted at 5-min intervals. Immediately they did five 10-sec sprints interspersed by 2-min rest intervals. Tests were performed on an individual race bicycle that was mounted on an ergometer. Steady-state power production on average was about 235 - 245 W, which corresponded to blood lactate concentrations of 4 - 5 mmol × l-1 and heart rate in the range of 160 - 170 beats × min-1. Power outputs as well as blood lactate levels and heart rates were similar between Crpyr and PL at all times. Total work performed during the 1-h trial was 872 ± 44 KJ in PL versus 891 ± 51 KJ in CRpyr. During the intermittent sprint test power peaked at about 800 - 1000 watt within 2 - 3 sec, decreasing by 15 - 20 % towards the end of each sprint. Peak and mean power outputs were similar between groups at all times. Peak lactate concentrations after the final sprint were ~11mmol × l-1 in both groups during both the pretest and the posttest. It is concluded that one week of creatine-pyruvate supplementation at a rate of 7 g × d-1 does not beneficially impact on either endurance capacity or intermittent sprint performance in cyclists.