Neurophysiological data
fatigue
Trials contaminated by prestimulus EMG activity (root mean squared EMG >10 μV; 100 ms before stimulation) were discarded. For all muscles, trials with MEP amplitudes >2 SDs outside the mean were also discarded (Experiment 1: 4.2% and 3.7% of the total trials were discarded in the fatigue and control sessions, respectively; Experiment 2: 0.7% and 0.65% of the total trials were discarded in the fatigue and control sessions, respectively). All participants had at least 10 valid trials per condition. To quantify CBI, SICI, and ICF, conditioned MEP amplitudes were expressed as a ratio of the nonconditioned MEP amplitude at each time point (