The Effect of Self-Paced and Prescribed Inter-Set Rest Strategies on Performance in Strength Training

Purpose: To assess pacing strategies using prescribed and self-selected inter-set rest periods and their influence on performance in strength trained athletes. Methods:Sixteen strength-trained male athletes completed three randomised heavy-strength training sessions (five sets, five repetitions) with different inter-set rest periods. The inter-set rest periods were: 3 minute (3MIN), 5 minute (5MIN) and Self-Selected (SS). Mechanical (power, velocity, work and displacement), surface muscle activity (sEMG) and subjective (Rating of Perceived Exertion -RPE) and readiness to lift (RTL) data were recorded for each set. Results:SS condition inter-set rest periods increased from sets 1 to 4 (207.52s > 277.71 s; p=0.01). No differences in mechanical performance were shown between the different inter-set rest period conditions. Power output (210 W; 8.03%) and velocity (0.03 m.s-1; 6.73%) decreased as sets progressed for all conditions (p<0.001) from set 1 to set 5. No differences in sEMG activity between conditions were shown, however vastus medialis sEMG decreased as the sets progressed for each condition (1.75%; p=0.005). All conditions showed increases in RPE as sets progressed (set 1: 6.1; set 5: 7.9) (p<0.001). Participants reported greater readiness to lift in the 5MIN condition (7.81) compared to the 3MIN (7.09) and SS (7.20) conditions (p<0.001). Conclusions:Self-selecting inter-set rest periods does not significantly change performance compared to 3MIN and 5 MIN conditions.. Given the opportunity, athletes will vary their inter-set rest periods to complete multiple sets of heavy strength training. Self-selection of inter-set rest periods may be a feasible alternative to prescribed inter-set rest periods.