Previously in this blog I reported on a U.S Track and Field Association study that indicated that stretching before exercise does not decrease the risk of running-related injuries (see this blog, Sept. 8, 2010). Now a review of 12 stretching-related studies reveals that stretching before exercise does not reduce perceived muscle soreness, either, in the days following exercise.
None of the studies of the effects of stretching on exercise-induced injury or soreness are considered scientifically ideal, however. Ideally, such studies would be randomized (subjects assigned randomly to either the stretch or no-stretch group) AND double-blind (neither the investigators nor the subjects would know which group each subject was in until the study was over). Unfortunately, subjects in exercise studies always know whether they are stretching or not, and therefore a double-blind study design is impossible! It’s conceivable that subject bias about the value of stretching affected the subjects’ judgment of their own post-exercise level of soreness. Until we have a truly objective measure of “soreness”, there’s no other way to conduct such studies. It’s the best we can do for now.
But from what we can tell so far, there’s no compelling evidence that stretching before exercise is either good or bad for you. Do it (or don’t do it) as you wish.
Reference: Henschke, N. and C.C. Lin. Stretching Before and After Exercise Does Not Reduce Delayed-onset Muscle Soreness. Br. J. Sports Med. 45:1249-1250, Dec. 2011.