在促進肌肉肥大的阻力訓練中同時增加離心負荷與安排組內休息對阻力運動表現與荷爾蒙反應的影響

Introduction: It has been shown that cluster set (CS) may allow for use of greater training intensities or greater number of repetitions to be performed during resistance training sessions. However, no study has yet examined whether CS allowing for greater training intensities to be performed with a given repetition can induce greater responses of blood lactate and anabolic hormones. On the other hand, eccentric-enhanced resistance training (refers to DAER) has been shown to produce superior growth hormone responses than traditional resistance training (refers to DCER). However, increases in eccentric loading may result in decreases in number of repetitions completed and possibly lead to reduction in training volume. To date, no study has yet examined the possible effects of combining DAER training with CS training in prevention of decreases in training volume, which may lead to greater hormonal responses after resistance training. Purpose: To examine effects of DCER training, CS training, combining DAER with CS training on metabolic stress (blood lactate) and hormonal responses (growth hormone and total testosterone) during a hypertrophic training protocol. Methods: Fifteen resistance-trained male subjects (23.5 ± 2.1 years, 174.5 ± 4.8 cm, 72.8 ± 6.5 kg) performed bench press followed by back squat exercises on smith machine in following 3 experimental conditions: eccentric/concentric loadings of 70%/70%1RM, 3 sets of 10 repetitions with 120s inter-set rest (DCER training); eccentric/concentric loadings of 80%/80%1RM, 3 sets of 2 cluster sets of 5 repetitions with 30s intra-set rest and 90s inter-set rest (CS training); eccentric/concentric loadings of 90%/70%1RM, 3 sets of 2 cluster sets of 5 repetitions with 30s intra-set rest and 90s inter-set rest (DAER+CS training). Repeated-measures and counter-balanced research design were used. Heart rate and rating of perceived exertion were collected following completion of each set. Blood samples were collected before exercise, immediately and 15 minutes after exercise for blood lactate (LAC), 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: LAC, GH, and T levels significantly increased immediately after resistance exercise in all 3 conditions. However, only significantly higher LAC and GH levels were observed in CS condition when compared with DCER condition. No significant differences were observed in LAC and GH levels after resistance exercise in DAER+CS condition when compared with DECR condition. Conclusions: When performing resistance training, the use of intra-set rest (CS training) may not only complete greater training intensity but also induce greater blood lactate and GH responses during a hypertrophy protocol.