The Effects of Active Versus Passive Interset Rest Intervals in the Bench-Press Exercise in Resistance-Trained Men: A Randomized Crossover Study.

Purpose: Interset rest (ISR) is a variable of resistance training (RT) that has received limited attention and focused mainly on the length of the ISR rather than examining the effects of different stimuli when using the same ISR duration. The aim of this study was to compare the effects of 2-minute passive (PAS) or active ISR (ACT) on intraset velocity loss, blood lactate concentrations, and rating of perceived exertion during bench press in resistance-trained men.

Methods: Fourteen participants (23.64 [2.02] y, 82.79 [10.74] kg, 181.50 [7.02] m, maximal power in bench press 660 [113] W) completed 2 RT sessions of 5 × 8 repetitions at maximal velocity using individual optimal load for maximal power output with 2-minute PAS or ACT ISR. During the ACT, participants completed repetitions of vertical chest press at 5% to 10% 1-repetition maximum at a controlled velocity. The intraset velocity loss was measured using a lineal encoder, and blood lactate concentrations and rating of perceived exertion before and after each set were registered.

Results: Intraset velocity loss was lower in ACT compared with the PAS protocol, without statistically significant differences (P = .571). Blood lactate concentrations increased across the session for both ISR protocols, but this increase was diminished in ACT compared with PAS, without statistical meaning (P > .05).

Conclusions: Continuing to perform the same activation during rest intervals was well-tolerated and may reduce the loss of performance due to accumulated workload throughout an RT session, suggesting that ACT may trigger a metabolic advantage in exercise performance for consecutive sets during an RT bout.