Resumen: The aim of this study was to analyze and compare the effects of post-activation potentiation (PAP ) on neuromuscular and metabolic parameters. METHODS: Seventeen (N.=17) men who were experienced in resistance training (4.6±1.4 years) completed two distinct PAP protocols on the horizontal bench press, in which the first consisted of 2 sets of 2 repetitions with a 90% load of one-repetition maximum and the second in 3 sets of 3 seconds of maximum voluntary isometric contraction (MVIC). Average power (POWa) and MVIC were assessed pre-potentiation and post-training, and blood lactate (BL) collections were performed pre-and post-potentiation and post-training. RESULTS: In the POWa, there was a significant decrease (P<0.05) among the pre-(431.35±77.19 watts) and postassessments in both PAP stimuli (isotonic: 368.26±67.77 watts and isometric: 358.04±74.67 watts) with no difference between them, in MVIC there was also a decrease without differences among PAP stimuli (control: 74.54±19.49 kgf; isotonic: 59.65±14.5 kgf and isometric 62.72±13.51 kgf) and in the BL, the control levels (isotonic: 2.59±0.54; isometric: 2.65±0.38 mmol) post-PAP were higher for the isotonic protocol (4.43±0.55 mmol), however, the levels did not show differences at the end of the training. CONCLUSIONS: We concluded that the PAP mechanism is ineffective after a tri-set method session, not showing plausible benefits that justify the daily routine in a gymnasium.