以时域特征为视角的骨骼肌激活后增强效应

Postactivation potentiation in skeletal muscle from the perspective of time domain characteristics

背景:研究表明适当的诱导练习后可以增大骨骼肌的输出功率,提高运动表现。但如何把握激活后增强效应的恢复时间仍是国内外学者的研究热点。目的:探究大负荷诱导练习后恢复时间对激活后增强效应的影响。方法:选取13名男性大学生田径运动员。激活后增强效应诱导练习采用90%1次最大重复量(1-repetition maximum,1-RM)重复3次杠铃半蹲,使用三维测力台对受试者静态半蹲跳进行前测和后测(15 s、3,6,9和12 min)。试验采用配对样本t检验对腾空高度、最大地面反作用力和峰值功率的前测值与后测值进行对比分析。结果与结论:(1)腾空高度基线值与3,6,9 min时观测值具有显著性差异(P<0.01),大力量组腾空高度变化率峰值和腾空高度峰值出现时间晚于小力量组;(2)最大地面反作用力基线值与15 s时观测值具有显著性差异(P<0.05),大力量组最大地面反作用力变化率峰值和最大地面反作用力峰值出现时间晚于小力量组;(3)峰值功率基线值与3,6 min时观测值具有显著性差异(P<0.01,P<0.05),大力量组峰值功率变化率峰值和峰值功率峰值出现时间晚于小力量组;(4)结果提示,90%1 RM强度下,重复3次杠铃半蹲诱导练习可诱导产生激活后增强效应。诱导产生激活后增强效应后,腾空高度峰值出现在6 min;最大地面反作用力峰值出现在3 min;峰值功率峰值出现在6 min。1-RM/体质量值越高,诱导练习后腾空高度、最大地面反作用力峰值、峰值功率的峰值出现时间越晚。

BACKGROUND： Appropriate induced exercise has been shown to increase the output power of skeletal muscle, and enhance sport performance. However, how to control the recovery time of postactivation potentiation is an issue of concern at home and abroad. OBJECTIVE： To investigate the effect of recovery time after heavy-load induced exercise on the postactivation potentiation. METHODS： Thirteen college track men were recruited. Postactivation potentiation was induced by half back-squat of three repetitions at 90% 1-repetition maximum（1-RM）. The static squat jump date was collected pre and post test（15 seconds, 3, 6, 9 and 12 minutes） using three-dimensional measuring platform. The pre and post date of flight height, maximum ground reaction force and peak power were analyzed by paired-t test. RESULTS AND CONCLUSION： The flight height at baseline was significantly different from that at 3, 6 and 9 minutes post-test（P〈0.01）, the peak of flight height change rate and peak of flight height in the high strength level group appeared later than those in the low strength level group. The maximum ground reaction force at baseline was significantly different from that at 15 seconds post-test（P〈0.05）, the peak of maximum ground reaction force change rate in the high strength level group appeared later than those in the low strength level group. The peak power at baseline was significantly different from that at 3 and 6 minutes post-test（P〈0.01）, the peak value of peak power change rate and peak power in the high strength level group appeared later than those in the low strength level group. All these findings indicate that half back-squat of three repetitions at 90% 1-RM can induce postactivation potentiation. Afterwards, the peak flight height appeared at 6 minutes, the peak maximum ground reaction force appeared at 3 minutes, and the peak power appeared at 6 minutes. The higher ratio of 1-RM/body mass, leads to latter appearance of peak of flight height, ground reaction force and peak power after induction training.