Similar neuromuscular and perceptual responses to low-intensity training with blood flow restriction at short versus long inter-set rest intervals

Abstract

Background

Increasing inter-set rest interval during low-intensity exercise with blood flow restriction (LI-BFR) may exacerbate metabolic stress, potentially enhancing muscle strength and hypertrophy responses to LI-BFR. Contrarily, perceptual responses (rate of perceived exertion [RPE] and pain) might be further impaired under increased inter-set rest interval.

Objective

We compared the neuromuscular and perceptual responses to LI-BFR performed with short vs. long inter-set rest intervals.

Design

randomized within-subject design.

Method

Thirteen physically-active men (22 ± 6 y; 1.75 ± 0.06 m; 75.9 ± 13.8 kg) were submitted to unilateral LI-BFR (30% one-repetition maximum, 1-RM) in the incline leg press exercise with one leg resting 60s between sets (G60) and the other resting 120s (G120). The training protocol consisted of 15 reps/set, 3 sets/session, 4 sessions/week for 3 weeks, while training pressure was established as 80% of the arterial occlusion pressure. Cross-sectional area (CSA) from whole quadriceps femoris was measured through magnetic resonance imaging. CSA and 1-RM were assessed at baseline and after training. RPE and pain were evaluated immediately after each set during the initial, middle and last training sessions.

Result

Both G60 and G120 were similarly effective in increasing whole quadriceps CSA (+5.7 ± 3.0% and +5.4 ± 2.5%, respectively; both P < 0.0001) and 1-RM (+9.7 ± 14.1% and +9.4 ± 13.5%, respectively; both P ≤ 0.05), with no significant between-group differences (all comparisons P > 0.05). RPE and perceived pain significantly reduced for G60 and G120 across training sessions (both P < 0.0001), but no between-group differences were shown (P = 0.98 and P = 0.52, respectively).

Conclusion

Both short and long inter-set rest intervals induce comparable neuromuscular and perceptual responses to LI-BFR.