Effects of Different Intraset Rest Durations on Lifting Performance and Self-perceived Exertion During Bench Press Exercise.

ABSTRACT: Ho, IMK, Luk, JTC, Ngo, JK, and Wong, DP. Effects of different intraset rest durations on lifting performance and self-perceived exertion during bench press exercise. J Strength Cond Res 35(8): 2114-2120, 2021-This study compared the number of successful repetitions, failure rates, and ratings of perceived exertion (RPEs) among intraset rest (ISR) protocols (0-, 20-, or 40-second rest between third and fourth repetitions) during bench press exercise with total 3 sets and 6 repetitions per set at 6 repetition maximum (6RM) load. Thirty-four college-aged men performed 6RM loads with ISR 0, 20, and 40 on 3 separate visits in a counterbalanced order while the total rest time and duration of each protocol was equated. Results showed failure rates of 32.4% for ISR0 (11 subjects with failed repetition), 14.7% for ISR20, and 2.9% for ISR40. The ISR had a small positive effect on increasing successful repetitions in: second set, ISR40 vs. ISR0 and ISR20 vs. ISR0 (both +0.2 rep, d = 0.28); third set, ISR40 vs. ISR0 (+0.5 rep, d = 0.55) and ISR20 vs. ISR0 (+0.4 rep, d = 0.39); and total number of repetition: ISR40 vs. ISR0 (+0.7 rep, d = 0.46) and ISR20 vs. ISR0 (+0.5 rep, d = 0.36). The ISR also had small effect on decreasing RPE in: second set, ISR40 vs. ISR0 (-0.6, d = -0.21); third set, ISR40 vs. ISR0 (-0.7, d = -0.26); and average RPE of the 3 sets, ISR40 vs. ISR0 (-0.6, d = -0.24). The longer ISR could further decrease RPE only in the third set (ISR40 vs. ISR20: -0.6, d = -0.23, small effect). Strength coaches may use the ISR40 rest redistribution to reduce RPE and enhance repetition sustainability.