Effect Of Single Vs Multiple Sets Of Resistance Exercise On Muscle Strength

Abstract

Most studies reported that performing resistance training with multiple sets per training session is more effective for increasing strength as training with a single set. However, only few studies compared the effects of single vs. multiple sets on strength between small vs. large muscle groups, and upper-body vs. lower-body muscle groups. PURPOSE: The purpose of this study was to determine the effect of single sets vs. multiple sets, during the early phase of adaptation, on different muscle group strength in untrained subjects. METHODS: Twenty six apparently healthy, untrained male participated in the study protocol. The volunteers were randomly assigned into one of two groups: 1) elbow flexion single set and knee extension three sets (E1-K3; n=13; 22.5 yrs), or 2) elbow flexion three sets and knee extension single set (E3-K1; n=1 3; 23.4 yrs). Subjects trained 2 days per week for 6 weeks and each workout consisted of 1 close chain knee extension exercise and 1 elbow flexion exercise. Training intensity varied between 8 repetition maximum (RM) and 12RM. Unilateral knee extension and elbow flexion strength were tested for both groups at 60°/s on a Biodex System 3 isokinetic dynamometer. Strength was expressed as peak torque (PT). Statistical evaluation of the data was measured using a 2 × 2 analysis of variance [group (E1-K3 and E3-K1) x time (pre and post)]. The probability level of statistical significance was set at p < 0.05 in all comparisons. RESULTS: The increase in PT of the knee extensors muscles from week 0 to 6 was significantly higher in the E1-K3 group (10.29%) than in the E3-K1 (3.78%) group, while no difference existed in PT gains between E1-K3 (7.75%) and E3-K1 (7.44%) of the elbow flexors muscles. CONCLUSIONS: It was concluded that performing three sets of strength training is superior to one set for increasing strength of the knee extensors muscles. It was also concluded that single-set training protocols for the elbow flexors muscles might be sufficient for untrained individuals in the early phases of a strength-training program.