Effects of inter-set stretching on acute hormonal and metabolic response: a pilot study

Purpose
The present study aimed to compare the acute hormonal and metabolic response following a resistance training (RT) session with and without inter-set stretching.

Methods
Overall, 13 men with minimum 1 year of experience with RT were randomly allocated to 2 groups: traditional RT group (TRT; n = 6; age: 22.5 ± 4.7 years; body weight: 83.1 kg ± 5.7 kg; height: 179.8 ± 6.9 cm; BMI: 25.73 ± 1.17 kg/m2) and stretching RT group (SRT; n = 7; age: 23.4 ± 4.3 years; body weight: 82.3 ± 11.7 kg; height: 177.7 ± 11.0 cm; BMI: 26.02 ± 2.5 kg/m2). The RT protocol consisted of 6 bench press sets to failure at 80% of 8 repetitions maximum, with a 1-minute rest interval between sets. During the rest interval, the TRT group remained resting, while the SRT group was submitted to shoulder anterior chain muscles stretching.

Results
The results revealed a higher increase in lactate (32%) and total leukocytes (17%) immediately following exercise in the SRT group as compared with the TRT group (p < 0.05). An increase in total testosterone and cortisol was observed in both groups, without differences between them (p > 0.05). There was a progressive decrease in the total number of repetitions completed along sets, without differences between groups.

Conclusions
The use of agonist stretching between sets increases the acute metabolic response during an RT session, which could be useful to intensify RT in trained participants.