Van Schuylenbergh R, Van Leemputte M, Hespel P
Exercise Physiology and Biomechanics Laboratory, Department of Kinesiology, Faculty of Physical Education and Physiotherapy, Katholieke Universiteit Leuven, Tervuursevest 101, B-3001 Leuven, Belgium.
Int J Sports Med. 2003 Feb;24(2):144-50. doi: 10.1055/s-2003-38400.
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 (Cr(pyr), 2 x 3.5 g x 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 x l -1 and heart rate in the range of 160-170 beats x min -1. Power outputs as well as blood lactate levels and heart rates were similar between Cr(pyr) and PL at all times. Total work performed during the 1-h trial was 872 +/- 44 KJ in PL versus 891 +/- 51 KJ in CR pyr. 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 approximately 11 mmol x 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 x d -1 does not beneficially impact on either endurance capacity or intermittent sprint performance in cyclists.
进行了一项双盲研究，以评估口服肌酸 - 丙酮酸对训练有素的自行车运动员运动表现的影响。在摄入肌酸 - 丙酮酸（Cr(pyr)，2×3.5 g×d-1，n = 7）或安慰剂（PL，n = 7）一周之前（预测试）和之后（后测试），评估耐力和间歇性冲刺表现。受试者首先进行1小时的计时赛，在此期间工作量可每隔5分钟进行调整。随后他们立即进行五次10秒的冲刺，中间穿插2分钟的休息间隔。测试在安装在测力计上的个人赛车自行车上进行。平均稳态功率输出约为235 - 245 W，这对应于4 - 5 mmol×l -1的血乳酸浓度和160 - 170次/分钟的心率。在所有时间点，Cr(pyr)组和PL组之间的功率输出以及血乳酸水平和心率均相似。在1小时试验中，PL组完成的总功为872±44 KJ，而CR pyr组为891±51 KJ。在间歇性冲刺测试中，功率在2 - 3秒内达到约800 - 1000瓦的峰值，在每次冲刺结束时下降15 - 20%。在所有时间点，两组之间的峰值和平均功率输出均相似。在预测试和后测试期间，两组在最后一次冲刺后的峰值乳酸浓度均约为11 mmol×l -1。得出的结论是，以7 g×d -1的剂量补充肌酸 - 丙酮酸一周对自行车运动员的耐力能力或间歇性冲刺表现均无有益影响。
