The Effects of 8-Week Skiing Training on Surface Electromyography and Microcirculation Function of Lower Limb Skeletal Muscles: a Randomized Controlled Trial
FU Beilun1,2, ZHU Huan1,2, ZHOU Shufeng1,2, LI Miao1,2, WAN Li1,2, WANG Kangfeng3, LU Biqiong3, HU Jiangping3
This study investigates the changes in sEMG (surface electromyography) signals and microcirculation function of lower limb muscles in male amateur skiers majoring in physical education before and after an 8- week skiing training intervention, and to explore the causes of sEMG changes from the perspective of microcirculation function. This study aims to provide a new research perspective and theoretical support for revealing the effects of skiing training on human muscle function. A total of 38 eligible subjects were recruited and randomly divided into a control group and an experimental group using a stratified block randomization method. The experimental group underwent an 8-week alpine skiing training program, with 5 sessions per week and 90 min per session. The 8-week training was divided into three phases: basic skiing training (2 weeks), special ability development training (3 weeks), and special ability enhancement training (3 weeks). During the basic skill training phase, the maximum skiing slope was 11° and the single-run distance was 0.15 km; during the special ability development training phase, the maximum slope was 22° and the single-run distance was 0.9 km; during the special ability enhancement training phase, the maximum slope was 27° and the single-run distance was 0.7 km. The control group maintained their regular daily routines without systematic exercise training. Before and after the experiment, the following indicators were measured for all subjects: muscle strength of the right lower limb, vertical jump height, as well as iEMG (integral electromyography), RMS (root mean square), MF (median frequency), MPF (mean power frequency) of the rectus femoris and lateral gastrocnemius during unweighted squat, and MR (microvascular reactivity), TcPO2 (transcutaneous oxygen partial pressure), SmO2 (muscle oxygen saturation) of the corresponding muscles. This study found that: (1) after the experiment, the muscle strength of the right lower limb and vertical jump height of the experimental group were significantly higher than those of the control group (P<0.01); (2) after the experiment, the MF and MPF values of the rectus femoris and lateral gastrocnemius in the experimental group were significantly higher than those in the control group (P<0.05); the iEMG and RMS of the rectus femoris, as well as the iEMG of the lateral gastrocnemius in the experimental group were significantly lower than those in the control group (P<0.05); the RMS of the lateral gastrocnemius in the experimental group was significantly lower than that in the control group (P<0.01); (3) after the experiment, the MR and TcPO2 of the rectus femoris, as well as the MR, TcPO2 and SmO2 of the lateral gastrocnemius in the experimental group were significantly higher than those in the control group (P<0.05); the SmO2 of the rectus femoris in the experimental group was significantly higher than that in the control group (P<0.01). 8-week skiing training can simultaneously improve the sEMG activity and microcirculation function of lower limb skeletal muscles in male amateur skiers majoring in physical education. However, further re- search is required to clarify whether a causal relationship exists between these two indicators. In summary, this study suggests that skiing training is an effective approach to enhance the function of lower limb skeletal muscles.
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