Older studies in animal models suggested that extreme static stretching elicited substantial increases in muscle hypertrophy. Trainee’s have since been trying to find different ways to apply static stretching techniques for the purposes of building more lean tissue or improving resistance training performance. The inter-set period has been an area of focus for the implementation of various stretching protocols. However, it is well established today that excessive stretching of the agonist muscles between sets can results in substantial decrements in performance, such as force output, number of repetitions performed, etc. For example, static stretching the pectoral muscles between sets of bench press will decrease power and endurance of the subsequent set. However, it remains unclear whether static stretching of the antagonistic muscle group offers any benefits.
A recent study published in Research in Sports Medicine evaluated the performance effects of antagonistic muscle group static stretching between sets of a resistance training exercise. A group of 10 male subjects with resistance training experience repeated two workouts in a randomized order. Both workouts consisted of 3 sets of 10RM (repetitions to failure) of the wide-grip seated row with 2 minutes rest between sets. For the experimental condition, the subjects underwent 40 seconds of pectoralis major static stretching (antagonist muscles during the row) directly before each set. The outcome variables that were recorded included the number of repetitions performed per set and surface electromyography (muscle activation) of the latissimus dorsi, biceps brachii and pectoralis major muscles.
The results showed that for the control condition (no stretching of the antagonist between sets), number of repetitions performed dropped by ~7% between sets 1-2 and by ~13% between sets 2-3. This was significantly different from the stretching group who only saw decrements of ~4.5% and ~9.4% between sets 1-2 and 2-3, respectively. EMG analysis showed the agonist muscle activation was significantly greater in the stretching group compared with the control group while antagonist muscle activation (pectoralis major) was not different between groups. This study demonstrates that 40 seconds of static stretching between sets off-sets performance decline (repetitions to failure) and increases agonist muscle activity. This may result in superior training adaptations such as size and strength gains when performed over a longitudinal training program.
Miranda, H., Maia, M. D. F., Paz, G. A., & Costa, P. B. (2015). Acute effects of antagonist static stretching in the inter-set rest period on repetition performance and muscle activation. Research in Sports Medicine, 23(1), 37-50.