Effect of Inter-Repetition Rest vs. Traditional Strength Training on Lower Body Strength, Rate of Force Development, and Muscle Architecture

Abstract

The purpose of the study was to investigate the effect of seven weeks inter-repetition rest vs. traditional strength training on lower body strength, rate of force development (RFD), and vastus lateralis (VL) muscle architecture. Sixteen male participants were assigned into two groups: the inter-repetition rest (IRRG) and the traditional (TG) group. Both groups performed the leg press exercise with four sets of six maximum repetitions (RM) for two training sessions per week. IRRG added a 20 s inter-repetition rest period between single repetitions. Before and after the training period, 1-RM in leg press, isometric leg press RFD, and peak force (PF), VL muscle architecture, vastus intermedius (VI) thickness, and quadriceps’ cross sectional area (CSA) with ultrasonography, were measured. Two way ANOVA for repeated measures was used for statistics. One-RM strength increased similarly for both groups (p < 0.05), while percentage increases in RFD were greater for IRRG compared to TG (p < 0.05). Isometric PF was increased similarly for both groups (p < 0.05). VL and VI thickness as well as CSA of the quadriceps increased similarly in both groups, while VL fascicle length increased more following IRRG compared to TG (IRRG: 4.8 ± 6.1% vs. TG: −3.9 ± 5.4%, p = 0.001). These results suggest that 20 s inter-repetition rest during strength training may effectively increase lower body explosive strength and muscle fascicle length without compromising muscle hypertrophy.

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

“…Specifically, the longer rest allowed resynthesis of phosphocreatine, which is important in execution of explosive actions [28]. The results of this study somehow coincide with previous studies indicating the maintenance of kinetics from longer IRRs [7,8,13,22,23]. For example, Lawton, Cronin [7] demonstrated greater power output (21-25%) during bench press with longer IRR when compared with the continuous set protocols [7].…”

“…Power, force output and velocity have been demonstrated to decrease with each repetition during high-intensity RT [4][5][6][7][8]. For example, Izquierdo et al [9] posted decreased velocity across repetitions to failure in squat and bench press exercises.…”

Biological Determinants of Track and Field Throwing Performance

“…Muscle architecture characteristics, namely the muscle thickness, the fascicle angle and the fascicle length ( Figure 3 ), have been considered as important factors contributing to muscle power production [ 66 , 67 , 68 ]. Muscle thickness and fascicle angle have been linked with muscle hypertrophy and strength [ 69 , 70 ]; thus, it is anticipated that athletes with greater muscle mass such as throwers may possess higher muscle thickness and fascicle angles. In addition, athletes with greater muscle thickness and fascicle angle may produce greater muscle strength and power compared to athletes with lower muscle thickness and fascicle angle [ 71 ].…”

Practical Application of Traditional and Cluster Set Configurations Within a Resistance Training Program

“…Although the authors in this study provide interesting data that support the use of cluster sets during the strength-power phase, it is still unknown whether trained athletes can gain the same benefits. In addition, Zaras et al (138) used leg press as their training intervention, which has been reported to be less effective for improving jump performance (134) and maximal strength (85) than free-weight exercises for the lower body, such as the squat. As such, more research on whether other training modalities (e.g., weightlifting movement and their derivatives) using cluster sets elicit greater increases in rapid force-generating capacities and athletic performance in trained individuals is needed.…”

“…In summary, traditional sets may be the primary option to be chosen for designing resistance training programs for the hypertrophy phase when considering the scientific literature that reports greater muscle hypertrophy after resistance training using traditional sets (30). However, not all longitudinal studies agree with this argument (5,138). Cluster sets may have the potential to induce greater muscle hypertrophy as they allow for the use of greater training loads.…”