The effects of 4 and 10 repetition maximum weight-training protocols on neuromuscular adaptations in untrained men

The purpose of this study was to identify and compare the strength, cross-sectional area, specific tension, and anthropometric changes elicited by 4 repetition maximum (RM) and 10RM weight-training protocols in untrained subjects. Twenty-four men (24.17 +/- 1.76 years) volunteered to participate and were randomly assigned to either the 4RM group or the 10RM group. Training was performed 3 times per week for 10 weeks; free weights were used to exercise the forearm extensors and flexors. The 4RM group performed 6 sets of 4 repetitions to failure and the 10RM group performed 3 sets of 10 repetitions to failure. Strength (1RM) was measured at 0, 6, and 10 weeks, and muscle cross-sectional area (determined through magnetic resonance imagery), specific tension (kilograms per square centimeter), and relaxed- and flexed-arm girth (corrected for skinfolds) were measured at 0 and 10 weeks. Significant (p < 0.05) increases in both forearm extensor and flexor 1RM strength, muscle cross-sectional area, specific tension, and flexed-arm girth occurred in both groups. The 4RM and 10RM loading intensities elicited significant and equal increases in strength, cross-sectional area, specific tension, and flexed girth. These results suggest that 4RM and 10RM weight-training protocols equated for volume produce similar neuromuscular adaptations over 10 weeks in previously untrained subjects.