Test-retest reliability of the electromyographic fatigue threshold for cycle ergometry

Introduction: The purpose of this study was to determine the intersession reliability of the electromyographic fatigue threshold (EMG(FT)) for cycle ergometry. Methods: On separate occasions, 10 healthy, college-aged men performed an incremental test to voluntary exhaustion on a cycle ergometer. The EMG amplitude vs. time relationships for each power output from the quadriceps femoris muscles were analyzed using linear regression. EMG(FT) was defined operationally as the average of the highest power output that resulted in a non-significant slope coefficient (P> 0.05) and the lowest power output that resulted in a significant (P< 0.05) positive slope coefficient. The EMG(FT) values for trials 1 and 2 were used to calculate the intraclass correlation coefficient (ICC). Results: Overall, the reliability of the EMG(FT) (ICC2,1=0.85; 95% confidence interval 0.49-0.96) was in the excellent category. Conclusions: The EMG(FT) for cycle ergometry is a reliable measure for assessing muscular fatigue. Muscle Nerve53: 803-807, 2016