Muscle Activation Does Not Increase After a Fatigue Plateau Is Reached During 8 Sets of Resistance Exercise in Trained Individuals

The premise of eliciting the greatest acute fatigue is accepted and used for designing programs that include excessive, potentially dangerous volumes of high-intensity resistance exercise. There is no evidence examining acute fatigue and neuromuscular responses throughout multiple sets of moderate-to-high intensity resistance exercise. Fifteen resistance-trained male subjects performed a single exercise session using 8 sets of Bulgarian split squats performed at 75% maximal force output. Maximal force output (N) was measured after every set of repetitions. Electromyographic (EMG) activity of vastus lateralis was monitored during all force trials and exercise repetitions. Repetitions per set decreased from the first to the third set (p < 0.001). Maximal force output decreased from preexercise to set 4 (p < 0.001). Electromyographic amplitudes during exercise did not change. Secondary subgroup analysis was performed based on the presence, or not, of a fatigue plateau (