Effect of Rest Interval Length Between Sets on Total Load Lifted and Blood Lactate Response During Total-Body Resistance Exercise Session

Abstract

Objectives: This study aimed to investigate the effect of different rest interval durations between sets during full-body resistance exercise sessions on total load lifted and blood lactate concentrations in resistance-trained individuals. Methods: Ten healthy young men (age: 23 ± 6.5 years; total body mass: 82.8 ± 10.6 kg, height: 177.3 ± 0.1 cm) randomly performed 3 resistance exercise sessions with different rest intervals between sets (30 seconds, 60 seconds and 120 seconds). The resistance exercise sessions consisted of 6 full-body exercises (bench press; seated low row; shoulder press; back squat; leg press 45° and seated calf raise) performed with 4 sets of 10 repetitions maximum (RM). Total load lifted (sets × repetitions × load (Kgf)) and lactate blood concentration were determined for each exercise session. One way, repeated measures analysis of variance (ANOVA) followed by Bonferroni’s post-hoc test were used for multiple comparisons. Results: The total load lifted was significantly (P < 0.001) lower for 30 seconds (26382.0 ± 4100.3 kg) rest interval compared with 60 seconds (28864.5 ± 4139.7 kg) and 120 seconds (30064.4 ± 3966.4 kg). The blood lactate response was not different among the 3 rest interval conditions investigated, with mean peak values of 7.05 ± 1.69, 7.26 ± 2.77 and 6.90 ± 3.79 mM for 30 seconds, 60 seconds and 120 seconds, respectively. Conclusions: In conclusion, rest interval durations of 60 seconds and 120 seconds between sets favored a higher total load lifted in the exercise session when compared to the 30 seconds rest interval. The rest protocols implemented in the present study promoted a similar metabolic response (e.g. blood lactate concentration) to a full-body resistance exercise session in trained subjects.