(8) ACUTE EFFECTS OF TRADITIONAL SET AND CLUSTER SET CONFIGURATIONS ON METABOLIC AND HORMONAL RESPONSES IN RESISTANCE-TRAINED MEN

Purpose: The purpose of this study was to examine the effects of traditional set (TS) and cluster set (CS) configurations on metabolic stress and hormonal responses during a single bout of resistance exercise. Methods: Fifteen resistance-trained male subjects (23.5 ± 2.1 years, 174.5 ± 4.7 cm, 72.8 ± 6.5 kg) were randomly assigned to two experimental conditions: 3 sets of 10 repetitions at 70%1RM with 120s inter-set rest (TS training); 3 sets of 2 cluster sets of 5 repetitions at 80%1RM with 30s intra-set rest and 90s inter-set rest (CS training). During each condition, subjects performed bench press first and followed by back squat exercises on smith machine. Rating of perceived exertion (RPE) and heart rate (HR) were collected after each set during bench press and squat exercises. In addition, blood samples were collected before exercise, immediately and 15 minutes after exercise for blood lactate (BLa), growth hormone (GH) and total testosterone (T) concentrations. A two-way repeated-measures ANOVA (condition x time) and the Bonferroni post hoc were used to analyze the data. Results: Although RPE and HR significantly increased during each set of both bench press and squat exercises, no significant differences were observed between conditions. BLa, GH, and T levels all significantly increased immediately after resistance exercise in both conditions. Furthermore, significantly higher BLa and GH levels were observed in CS training when compared with TS training. No significant differences in T levels were observed after resistance exercise between conditions. Conclusions: When performing a bout of resistance exercise, the use of intra-set rest (CS training) may not only complete greater training intensity but also induce greater blood lactate and GH responses. Practical Applications: Training volume and intensity are two important variables for induce greater anabolic hormonal responses and consequently greater hypertrophy. Therefore, during a hypertoric protocol, the use of cluster set configuration can help lift heavier while maintain similar RPE and HR and induce greater anabolic hormonal responses in resistance-trained men. Acknowledgements: This study was funded by Taiwan’s National Science and Technology Council.