UTILITY OF ELECTROMYOGRAPHIC FATIGUE THRESHOLD DURING TREADMILL RUNNING

Abstract

Introduction: We investigated 2 different methods for determining muscle fatigue threshold by electromyography (EMG).Methods: Thirteen subjects completed an incremental treadmill running protocol for EMG fatigue threshold (EMG(FT)) determination based on the critical power concept (EMG(FT)1) and the breakpoint in the linear relationship between EMG amplitude and exercise intensity (EMG(FT)2). Then, both the EMGFT1 and EMG(FT)2 were tested in a continuous treadmill running protocol. EMG was recorded from the rectus femoris (RF), vastus lateralis (VL), biceps femoris (BF), and lateral gastrocnemius (LG) muscles. Results: For BF, EMG(FT)2 was higher than EMGFT1, and EMGFT1 for BF was lower than EMGFT1 for LG. EMG of RF was higher at EMG(FT)2 than at EMGFT1, and LG EMG was lower at EMGFT2. Conclusions: EMGFT can be determined during a single treadmill running test, and EMGFT1 may be the most appropriate method to estimate the muscle fatigue threshold during running.