Changes in joint kinematics and kinetics through the implementation of inter-repetition rest protocols in snatch training

Abstract

Background and Study Aim. Inter-repetition rest pertains to a short period of rest between repetitions during strength training. Manipulating inter-repetition rest may influence fatigue accumulation, manifesting alteration in lifting mechanics. This study aimed to examine the effects of different inter-repetition rest protocols on joint velocity and ground reaction force during snatch exercise.
 Material and Methods. Fifteen male (n=15) athletes participated in this study (age = 23.0 ±2.31 years; body weight = 65.32 ± 1.37 kg; height = 168.80 ± 5.64 cm; snatch one repetition maximum (1RM)/bodyweight = 0.78 ± 0.12), performing three sets of 5 repetitions at 85% 1 Repetition Maximum snatch with 10, 30, or 50 seconds of inter-repetition rest implemented randomly across three sessions. Ankle, knee, and hip kinematics and ground reaction force in the three protocols were used for comparison. The participants visited the exercise science laboratory for four sessions between 0800-1700 hrs. These sessions were separated by 72 hours.
 Results. One-way repeated measure analysis of variances (ANOVA) showed a significant effect of inter-repetition rest on the maintenance of kinematic and kinetic variables. The ground reaction force for 10 seconds inter-repetition rest protocol showed a significant drop in force output across repetition (p = .037, p < 0.05).
 Conclusions. The utilization of inter-repetition rest in snatch exercise may reduce neuromuscular fatigue across repetitions, maintaining consistent performance output. Specifically, the 50 second inter-repetition rest protocol reduced the negative effect of neuromuscular fatigue in the kinematic and kinetic variables during snatch exercise.