Acute and delayed response to resistance exercise leading or not leading to muscle failure.

This study compared the time course of recovery following two resistance exercise protocols differing in the number of repetitions per set with regard to the maximum possible (to failure) number. Ten men performed three sets of 6 versus 12 repetitions with their 70% 1RM (3 × 6 [12] versus 3 × 12 [12]) in the bench press (BP) and squat (SQ) exercises. Mechanical [CMJ height, velocity against the 1 m s load (V -load)], biochemical [testosterone, cortisol, growth hormone, prolactin, insulin-like growth factor-1, creatine kinase (CK)] and heart rate variability (HRV) and complexity (HRC) were assessed pre-, postexercise (Post) and at 6, 24 and 48 h-Post.