Loaded Inter-set Stretching for Muscular Adaptations in Trained Males: Is the Hype Real? (Aug, 10.1055/a-1529-6281, 2021)

The study examined the effects of adding a loaded stretch in the inter-set rest period (ISS) compared to traditional resistance training (TR) on muscular adaptations in resistance-trained males. Twenty-six subjects were randomly assigned into two groups (ISS: n=12; TR: n=14) and underwent an 8-week training regimen. Subjects in ISS underwent an additional loaded stretch for 30s at 15% of their working load from the prior set during the inter-set rest periods. Muscle thickness of the pectoralis major at the belly (BMT) and lateral (LMT) portions, One-repetition maximum (1RM) and repetitions-to-failure (RTF) on the bench press exercise were measured at baseline and post 8 weeks of training. Additionally, volume load and perceptual parameters for exertion and recovery were measured. Both groups had similar total volume load and average perceptual parameters (p>0.05). There was a main time effect (p<0.01) for all but one dependent variable indicating that both groups responded similarly across time [(BMT: ISS=2.71.7mm; TR= 3.0 +/- 2.2mm), (LMT: ISS=3.2 +/- 1.6mm; TR=2.8 +/- 1.7mm, (1RM: ISS=6.6 +/- 3.8kg; TR=7.5 +/- 5.7kg). Repetitions-to-failure did not change in either group (RTF: ISS=0.0 +/- 2.1 repetitions; TR=0.0 +/- 2.3 repetitions, p>0.05). Our results suggest that addition of a loaded ISS does not affect muscular adaptations either positively or negatively in resistance-trained males.