Abstract des Autors

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, 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 and heart rate in the range of 160 - 170 beats/min. 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 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 does not beneficially impact on either endurance capacity or intermittent sprint performance in cyclists. Verf.-Referat