Comparison of the effect of rest interval between sets and set – repetition configuration during bouts of eccentric exercise on muscle damage and inflammatory markers

Abstract

Background and Objective: Various studies have demonstrated that different rest Intervals has a significant effect on hormonal, metabolic and cardiovascular responses. This factors can lead to different muscle damage responses. Materials and Methods: 40 untrained subjects (25.4 ± 0.068 years, height 1.74 ± 0.97 cm and weight 30.8 ± 8.48 kg) in three sessions of eccentric resistance exercise with 24 hours rest between each session Participated in this study. Subjects were divided into 4 groups, A group:  5 sets of 10 repetition with the interset rest interval 1 minutes, B group: 10 sets of 5 repetition with the interset rest interval 3 minutes, C group: 10 sets of 5 repetition with the interset rest interval 3 minutes and D group: 5 sets of  10 repetition with the interset rest interval 3 minutes that performed 50 eccentric contractions with 85% of one repetition maximum. Each set includes 10 or 5 contractions that lower a person’ s weight in 3 s and at least 2 s to reach the next contraction without weights placed in full flexion Around 1- or 3-min rest was given between each set. The experimental protocol was repeated for three consecutive days. The range of motion, the arm circumference, soreness and Alpha necrosis tumor factor were measured immediately before , immediately after and 24 hours after training. Results: Variance analysis with repeated measure demonstrated,  non-dominant arm circumference(P= 0.44), soreness (P= 0.76) and alpha necrosis tumor factor (P= 0.37) in different time points in 4 groups significantly increased and the range of motion (P= 0.44) decreased, but no significant difference in all dependent variables were found in 4 groups at different time points (P <0.05). Conclusion: Mechanisms of muscular damage caused by consecutive eccentric activities is independent of manipulating resistance exercise components (rest and the number of set-repetition) and possibly related to the muscular pressure entering to the muscles.