• amplitude;
  • exercise;
  • exercise physiology;
  • fatigue;
  • neuromuscular response


Introduction: We examined the individual patterns of responses for electromyographic (EMG) amplitude and mean power frequency (MPF) during incremental treadmill running. Methods: Nine physically active men performed incremental treadmill running at a constant grade of 1%. The EMG signal was recorded from the 3 superficial quadriceps femoris muscles during the work bout. Results: The results of the polynomial regression indicated that the linear model best fit the data for the composite data for all 3 muscles and the majority (7 of 9) of subjects. There were no consistent patterns of responses for the EMG MPF responses. Also, there were no significant (P > 0.05) muscle × running velocity interactions for EMG amplitude and MPF. Conclusions: These results indicate consistent patterns of responses for EMG amplitude during incremental treadmill running, regardless of which muscle was studied. Muscle Nerve 48: 938–944, 2013