At some point in your athletic career, you’ve probably wanted, or you will want, to increase the size of your muscles. This is particularly important for young athletes beginning a weight training program or for those looking to compete at a higher level against bigger and stronger opponents.
The standard method of hypertrophy training—the process of increasing muscle size—has proven to be quite effective [more on hypertrophy training here]. However, according to new research, stretching may be a powerful way to increase the effects of hypertrophy training.
A recent article in the Journal of Strength and Conditioning suggests that stretching between sets forces muscles to work when they contract against the stretch. The more a muscle works, the more it will increase in size. This is the rationale behind hypertrophy training, which uses high reps, light weight and short rest time to work muscles to fatigue. In theory, combining hypertrophy training with stretching between sets should result in greater size gains because of the additional work performed by the muscle.
While the theory appears plausible, it remains to be seen whether static or active stretching works better. Also, more research is needed on the effects of stretching on exercise form. Before implementing inter-set stretching in your training program, wait for more definitive info on how best to do it for increased muscle size.