Acute effects of different number of sets and non-equalized volume on muscle thickness, peak force, and physical performance in recreationally-trained participants

Abstract

The purpose of this study was to measure the acute effects of resistance training (RT) protocols with a different number of sets and non-equalized volume on muscle thickness, peak force, and physical performance in recreationally-trained participants. Fifteen participants performed the unilateral biceps curl exercise in four different RT protocols (G4: 4 sets of 10RM, G8: 8 sets of 10RM, G12: 12 sets of 10RM, and G16: 16 sets of 10RM). The average number of repetitions (ANR), the total number of repetitions (TNR), time under tension (TUT), muscle thickness (MT), peak force (PF), and rating of perceived exertion (sRPE) were measured pre-test and post-test. ANOVAs were used to test differences between all dependent variables. For ANR, there were differences between G4xG8, G4xG12, and G4xG16 and between RT protocols for TNR (p<0.05). There were differences for all RT protocols and between G12 and G4, G8, and G16 for TUT (p<0.05). MT increased and PF decreased for all RT protocols (p<0.001). In conclusion, G8, G12, and G16 showed lower ANR than G4, TNR increased with increasing sets, and TUT increased in all RT protocols. PF decreased with increasing sets and all RT protocols increased MT. The sRPE was similar between RT protocols.