Gaitanos G C, Williams C, Boobis L H, Brooks S
Department of Physical Education, Sports Science, and Recreation Management, Loughborough University, Leicestershire, United Kingdom.
J Appl Physiol (1985). 1993 Aug;75(2):712-9. doi: 10.1152/jappl.1993.75.2.712.
Eight male subjects volunteered to take part in this study. The exercise protocol consisted of ten 6-s maximal sprints with 30 s of recovery between each sprint on a cycle ergometer. Needle biopsy samples were taken from the vastus lateralis muscle before and after the first sprint and 10 s before and immediately after the tenth sprint. The energy required to sustain the high mean power output (MPO) that was generated over the first 6-s sprint (870.0 +/- 159.2 W) was provided by an equal contribution from phosphocreatine (PCr) degradation and anaerobic glycolysis. Indeed, within the first 6-s bout of maximal exercise PCr concentration had fallen by 57% and muscle lactate concentration had increased to 28.6 mmol/kg dry wt, confirming significant glycolytic activity. However, in the tenth sprint there was no change in muscle lactate concentration even though MPO was reduced only to 73% of that generated in the first sprint. This reduced glycogenolysis occurred despite the high plasma epinephrine concentration of 5.1 +/- 1.5 nmol/l after sprint 9. In face of a considerable reduction in the contribution of anaerobic glycogenolysis to ATP production, it was suggested that, during the last sprint, power output was supported by energy that was mainly derived from PCr degradation and an increased aerobic metabolism.
八名男性受试者自愿参与本研究。运动方案包括在自行车测力计上进行十次6秒的全力冲刺，每次冲刺之间休息30秒。在第一次冲刺前后以及第十次冲刺前10秒和冲刺后立即从股外侧肌采集针吸活检样本。维持第一次6秒冲刺中产生的高平均功率输出（MPO，870.0±159.2瓦）所需的能量，由磷酸肌酸（PCr）降解和无氧糖酵解同等贡献提供。实际上，在最初6秒的最大运动期间，PCr浓度下降了57%，肌肉乳酸浓度增加到28.6毫摩尔/千克干重，证实了显著的糖酵解活性。然而，在第十次冲刺中，尽管MPO仅降至第一次冲刺时产生的MPO的73%，但肌肉乳酸浓度没有变化。尽管在第9次冲刺后血浆肾上腺素浓度高达5.1±1.5纳摩尔/升，但糖原分解仍减少。鉴于无氧糖原分解对ATP生成的贡献大幅减少，有人提出，在最后一次冲刺期间，功率输出主要由PCr降解和增加的有氧代谢产生的能量支持。
