Rest interval between resistance exercise sets: length affects volume but not creatine kinase activity or muscle soreness.

PURPOSE: To compare differences between two different rest interval lengths between sets on the volume completed, muscle damage and muscle soreness during a resistance exercise bout.

METHODS: Twenty-eight healthy sedentary men (18 ± 1 y old) volunteered to participate in this study and were divided into the 1 min (1RI; n = 14) or 3 min (3RI; n = 14) rest interval length between sets. They were submitted to maximal voluntary isometric contraction strength (MVC) and then performed a resistance exercise protocol constituted for three sets of biceps curl at 40% of MVC with 1 min (1RI group) or 3 min (3RI group) interval length between sets. Each bout was performed to voluntary fatigue and the workout volume completed was calculated. Subjects provided blood samples before each bout, and at 24, and 48 h following exercise to evaluate serum CK activity. Muscle soreness was analyzed through visual analog scale, which was presented to subjects before first bout, immediately after exercise protocol and at 24, and 48 h following exercise.

RESULTS: The results demonstrated that the subjects with longer rest intervals provide greater workout volume as expected, but there were no differences in serum CK activity and muscle soreness between groups.

CONCLUSION: Training with high-volume, low-intensity resistance training, exercising with short rest intervals does not appear to present any additional challenge to recovery in untrained subjects.