To stretch or not to stretch for improved strength is a question that endures. Some support the practice; others don’t. A new study may have put the debate to rest.
Published in the Journal of Strength & Conditioning Research (2012; doi: 10.1519/JSC.0b013e31828054b7), the study aimed to determine what impact—if any—stretching would have on strength production. The researchers employed three procedures: a warm-up plus static stretch before each session; a stretch prior to each training set; and no stretch at all throughout the session. Thirty participants were divided among the three groups for 10 weeks. The strength component featured eight exercises performed at an 8-repetition maximum. The researchers measured strength levels and basal serum insulin-like growth factor 1 (IGF-1) before and after the intervention.
Final data revealed strength improvements across all exercises for the no-stretch group, but only in some exercises for both stretching groups. The no-stretch group also showed increases in IGF-1 postexercise, whereas the others did not.
The authors concluded that strength can improve with a prestretch, an in-workout stretch or no stretch at all—but in this study, the most significant impact on both strength and IGF-1 occurred among the no-stretch group.