常运动对大学生Wingate无氧运动能力的影响

摘要

目的 为研究有规律的运动对大学生无氧运动能力的影响,采用Wingate功率自行车测试比较常运动和久坐大学生的无氧做功能力,并用表面肌电信号分析下肢主要肌群无氧疲劳特征.方法 募集38名男大学生,分为常运动和久坐大学生两组,每组各19名.常运动组的质控标准是每周每次运动超过30min、每周运动次数≥4次;0~3次则为久坐组.采用日本COMBI公司PowerMax Ⅶ功率自行车进行Wingate无氧功率测试,比较两组学生最大功率输出(peak power output,PP)、平均功率(mean power output,MP)和无氧疲劳指数(anaerobic fatigue index,AFI)的差异.同时采集了Wingate运动过程中下肢股直肌、股外侧肌、股内侧肌和股二头肌的表面肌电信号,利用自主构建的非线性小波对表面肌电信号的强度和平均功率频率(mean power frequency,MPF)进行分析,检测肌肉纤维的募集与肌肉无氧疲劳状况.结果 常运动大学生功率自行车PP和MP显著高于久坐大学生(P<0.05),AFI明显小于久坐大学生.肌电信号MPF随着疲劳的产生而持续下降,常运动组的下降趋势比久坐组显著.肌电信号的强度两组也呈现不同的趋势.结论 常运动组大学生的无氧运动能力显著高于久坐组.无氧运动能力与快肌纤维密切相关,结合功率输出和肌电信号分析,大学生进行有规律的运动对于增加快肌纤维的比例和面积,并进一步增加肌肉的爆发力和速度有积极的影响.%Objective To study the effect of the physical activity on the anaerobic exercise capacity,the Wingate test is taken to compare the anaerobic capacity between physically active students and sedentary students,and the naerobic fatigue characteristics of lower limb muscle groups are analyzed by surface electromyography (sEMG) signals.Methods We recruited 38 college male students,19 sedentary students and 19 physically active students,to perform the Wingate test on a bicycle ergometer.The differences in peak power output (PP),mean power output (MP),and anaerobic fatigue index (AFI) were compared between the two groups.The selection criteria was that the physically active students participated exercises more than 4 times a week and more than 30min a time,whereas the sedentary students participated exercises less than 3 times a week.The sEMG signals from rectus femoris,vastus medialis,vastus lateralis,biceps femoris long head were recorded during the Wingate tests.sEMG signals were analyzed by a wavelet transform method.Results The physically active students reached significantly higher PP and MP than sedentary students (P <0.05).The sEMG mean power frequency (MPF) from the four muscles decreased during the Wingate tests,and the decline of MPF were steeper for the physically active students than for the sedentary students.The EMG intensity showed different trends for the two groups of students.The anaerobic exercise capacity was closely related to the fast-twitch fiber.Conclusions The physically active students show significantly higher anaerobic capacity than the sedentary students.The anaerobic capacity is closely related to the fast-twitch fibers.Our results suggest that regular physical activities can increase the area of the fast-twitch fibers,which in turn increase muscle power output and speed.