Fig. 6.

Representative, averaged contraction-by-contraction EMG (AEMG) values from the left vastus medialis during two constant-load, knee extension trials performed until failure at the 0.6 duty cycle condition. Force outputs during the 24 s and 275 s trials were nearly constant; however, EMG activity increased throughout each exhaustive trial and did so more rapidly in the shorter vs. longer trials. AEMG values are standardized (S.U.) to the first four contractions performed in the 275-s trial.