The recovery of repeated-sprint exercise is associated with PCr resynthesis, while muscle pH and EMG amplitude remain depressed.
The recovery of repeated-sprint exercise is associated with PCr resynthesis, while muscle pH and EMG amplitude remain depressed.
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DOI：
10.1371/journal.pone.0051977
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Bishop D
中科院分区：
文献类型：
--
作者：
Mendez-Villanueva A;Edge J;Suriano R;Hamer P;Bishop D
重复冲刺运动(RSE)中功率输出的维持和恢复的生理等价性仍有待充分阐明。因此，为了提高我们对RSE表现决定因素的了解，我们的目标是确定力竭运动(影响肌肉内和神经因素)后的恢复情况，同时测定肌肉中三磷酸腺苷(ATP)、磷酸肌酸(PCr)和pH值的浓度以及肌电(EMG)活动(反映净运动单位活动的指标)的变化。8名青年男子在自行车测功机上进行了10、6-S全力以赴的冲刺，其间穿插着30名S的恢复，在被动恢复6分钟后，又进行了5次6-S的冲刺，再次穿插着30名S的被动恢复。分别于安静时、前10次冲刺后即刻和恢复后6分钟取股外侧肌活检。在整个运动过程中，从表面电极获得股外侧肌的肌电活动。在前十个短跑中，总做功(TW)、[ATP]、[PCR]、pH和肌电幅度均显著下降(P<；0.05)。恢复6min后，SPRINT 11的TW恢复到SPRINT 1的86.3±7.7%，ATP和PCR值分别恢复到静止值的92.6±6.0%和85.3±10.3%，但肌肉pH和肌电幅值仍然受到抑制。聚合酶链式反应的重新合成与Sprint 11所做的TW(r = 0.79，P<；0.05)和Sprint 11至15所做的TW(r = 0.67，P<；0.05)相关。在最后五次冲刺(冲刺11至15)中，TW/肌电比率的∼下降幅度是前五次冲刺(冲刺1至5)中的2倍，导致机械功率(即TW)相对于肌电的不成比例的下降。因此，我们得出结论，在重复短跑过程中不能产生功率输出主要是由肌肉内疲劳信号介导的，可能与PCR代谢的控制有关。
The physiological equivalents of power output maintenance and recovery during repeated-sprint exercise (RSE) remain to be fully elucidated. In an attempt to improve our understanding of the determinants of RSE performance we therefore aimed to determine its recovery following exhaustive exercise (which affected intramuscular and neural factors) concomitantly with those of intramuscular concentrations of adenosine triphosphate [ATP], phosphocreatine [PCr] and pH values and electromyography (EMG) activity (a proxy for net motor unit activity) changes. Eight young men performed 10, 6-s all-out sprints on a cycle ergometer, interspersed with 30 s of recovery, followed, after 6 min of passive recovery, by five 6-s sprints, again interspersed by 30 s of passive recovery. Biopsies of the vastus lateralis were obtained at rest, immediately after the first 10 sprints and after 6 min of recovery. EMG activity of the vastus lateralis was obtained from surface electrodes throughout exercise. Total work (TW), [ATP], [PCr], pH and EMG amplitude decreased significantly throughout the first ten sprints (P<0.05). After 6 min of recovery, TW during sprint 11 recovered to 86.3±7.7% of sprint 1. ATP and PCr were resynthesized to 92.6±6.0% and 85.3±10.3% of the resting value, respectively, but muscle pH and EMG amplitude remained depressed. PCr resynthesis was correlated with TW done in sprint 11 (r = 0.79, P<0.05) and TW done during sprints 11 to 15 (r = 0.67, P<0.05). There was a ∼2-fold greater decrease in the TW/EMG ratio in the last five sprints (sprint 11 to 15) than in the first five sprints (sprint 1 to 5) resulting in a disproportionate decrease in mechanical power (i.e., TW) in relation to EMG. Thus, we conclude that the inability to produce power output during repeated sprints is mostly mediated by intramuscular fatigue signals probably related with the control of PCr metabolism.
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影响因子：
3.4
作者：
ENOKA, RM;TRAYANOVA, N;STUART, DG
通讯作者：
STUART, DG
影响因子：
4.5
作者：
Karatzaferi, C;de Haan, A;Sargeant, AJ
通讯作者：
Sargeant, AJ
DOI：
10.1249/01.mss.0000175855.35403.4c
发表时间：
2005-11-01
期刊：
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
影响因子：
--
作者：
Edge, J;Bishop, D;Dawson, B
通讯作者：
Dawson, B
影响因子：
3.4
作者：
BIGLANDRITCHIE, B;WOODS, JJ
通讯作者：
WOODS, JJ
DOI：
10.1152/ajpregu.00386.2001
发表时间：
2002-02-01
影响因子：
2.8
作者：
Deschenes, MR;Giles, JA;Kraemer, WJ
通讯作者：
Kraemer, WJ