AIM:There is an emerging body of knowledge indicating staticstretching(SS) acutely and adversely affectsmuscleperformance. The purpose of this study was to determine if SS using more representative stretch durations affectsmuscleperformance and to establish if changes inmuscleperformance were influenced by the duration of stretch.
METHODS:Following 2 familiarization sessions, 16 recreationally trained males and females participated in 2 randomly ordered experimental sessions. In each session maximal effort hamstring performance was assessed prior to and immediately after 1 of 2stretchingprotocols. During one of the protocols participants were required to hold each stretch for 15 s while stretch duration in the second protocol was 30 s. Both protocols consisted of 3 repetitions of 2stretchingexercises. A Kincom isokinetic dynamometer was used to assess hamstring performance during isometric, concentric, and eccentric actions.RESULTS:For each of the threemuscleactions a repeated measures ANOVA revealed a significant main effect of time (pre- vs poststretch, P<0.05) but no interaction effect (time x SS protocol). Furthermore, the stretch-induced deficits inmuscleperformance were consistent acrossmuscleaction type.
CONCLUSIONS:SS incorporating stretch durations typical of those employed pre-exercise were sufficient to impairmuscleperformance and the duration of stretch did not influence the degree of force loss. Inclusion of SS, even with short stretch durations, in preparation for strength activities is not appropriate. (Brandenburg JP.Duration of stretch does not influence the degree of force loss following staticstretching.Journal of Sports Medicine & Physical Fitness. 46(4):526-34, 2006 ).