Tan Yajun, Liu Yang, Ye Ruibin, Xu Hanxiao, Nie Wenliang, Lu Jian, Zhang Bin, Wang Chun, He Benxiang
Sport Hospital, Chengdu Sport University, Chengdu, China.
School of Physical Education and Sport Training, Shanghai University of Sport, Shanghai, China.
Sports Med Health Sci. 2020 Feb 25;2(1):25-32. doi: 10.1016/j.smhs.2020.02.004. eCollection 2020 Mar.
We studied the muscle fatigue and recovery of thirty male sprinters (aged 18-22 years) using the Frequency Analysis Method (FAM). The interferential currents (ICs) with different thresholds for sensory, motor and pain responses, the maximal voluntary contraction (MVC), and the amplitude of the surface EMG (aEMG, sEMG) were assessed prior to and immediately after an acute explosive fatigue training session, and during one-week recovery. We found that IC increased on average from 32.3 ± 8.9 mA to 37.5 ± 7.5 mA in sensory response at 10 Hz immediately post training ( = 0.004) but decreased at 24-hr post training ( = 0.008) and returned to pre-levels thereafter. Motor and pain response patterns at 10 Hz were similar (motor: = 0.033 and 0.040; pain: = 0.022 and 0.019, respectively). The change patterns of ICs were similar to but prior to the changes of sEMG. The agreement between IC assessment and amplitude of sEMG (aEMG)/MVC ratio was good (>95%). The present study suggested that the changes in ICs were prior to the changes in both the aEMG and force during fatigue. These changes may reflect the physiological sensory change due to peripheral fatigue. FAM may be useful as an effective early detection and simple tool for monitoring muscle fatigue during training and recovery in athletes.
我们使用频率分析法（FAM）研究了30名男性短跑运动员（年龄在18 - 22岁之间）的肌肉疲劳与恢复情况。在急性爆发性疲劳训练前、训练后即刻以及为期一周的恢复期间，评估了具有不同感觉、运动和疼痛反应阈值的干扰电流（ICs）、最大自主收缩（MVC）以及表面肌电图（aEMG，sEMG）的幅度。我们发现，训练后即刻10Hz时感觉反应的IC平均从32.3±8.9mA增加到37.5±7.5mA（P = 0.004），但在训练后24小时下降（P = 0.008），此后恢复到训练前水平。10Hz时运动和疼痛反应模式相似（运动：P分别为0.033和0.040；疼痛：P分别为0.022和0.019）。ICs的变化模式与sEMG的变化相似但更早出现。IC评估与sEMG幅度（aEMG）/MVC比值之间的一致性良好（>95%）。本研究表明，在疲劳过程中ICs的变化先于aEMG和力量的变化。这些变化可能反映了由于外周疲劳引起的生理感觉变化。FAM可能作为一种有效的早期检测方法和简单工具，用于监测运动员训练和恢复期间的肌肉疲劳。
