Change of bio-electric interferential currents of acute fatigue and recovery in male sprinters

Yajun Tan; Yang Liu; Ruibin Ye; Hanxiao Xu; Wenliang Nie; Jian Lu; Bin Zhang; Chun Wang; Benxiang He

doi:10.1016/j.smhs.2020.02.004

Change of bio-electric interferential currents of acute fatigue and recovery in male sprinters

Sports Med Health Sci. 2020 Feb 25;2(1):25-32. doi: 10.1016/j.smhs.2020.02.004. eCollection 2020 Mar.

Authors

Yajun Tan¹, Yang Liu², Ruibin Ye¹, Hanxiao Xu¹, Wenliang Nie³, Jian Lu⁴, Bin Zhang⁵, Chun Wang⁶, Benxiang He⁶

Affiliations

¹ Sport Hospital, Chengdu Sport University, Chengdu, China.
² School of Physical Education and Sport Training, Shanghai University of Sport, Shanghai, China.
³ School of Sport Science, Lingnan Normal University, Zhanjiang, China.
⁴ School of Sports and Health, East China Normal University, Shanghai, China.
⁵ Department of Orthopedics, Sichuan Province Traditional Chinese Medicine Hospital, Chengdu, China.
⁶ School of Sport Medicine and Health, Chengdu Sport University, Chengdu, China.

Abstract

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 (p = 0.004) but decreased at 24-hr post training (p = 0.008) and returned to pre-levels thereafter. Motor and pain response patterns at 10 Hz were similar (motor: p = 0.033 and 0.040; pain: p = 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.

Keywords: BMI, body mass index; EMG, electromyography; FAM, frequency analysis method; Fatigue; Frequency analysis method; ICs, interferential currents; Interferential current; MVC, maximal voluntary contraction; Maximal voluntary contraction; Surface electromyogram; aEMG, amplitude of surface electromyography; sEMG, surface electromyography.