Does Stretching Prior to Exercise Reduce the Risk of Injury?
We are all told that we should stretch before undertaking vigorous exercise but does scientific research support this. Pre-workout stretching seems to be a logical thing to do as tight muscles/tendons probably have a greater susceptibility to strain during exercise (when compared with relaxed-flexible soft tissues). However if we stretch are we less likely to get injured? The research evidence is contradictory.
Some studies have found support for the hypothesis, others no difference (and some that stretching prior to a work-out can actually increase the prevalence to injury!). For example in a study of 1543 athletes who ran in the Honolulu Marathon, 47% of all male runners who stretched regularly were injured during a one-year period while only 33% of male runners who didn’t stretch were hurt (1).
Even when the research accounted for the fact that the strongest predictor of a future injury is a past injury and excluded runners who had taken up stretching after a previous injury, the stretchers had a 33% greater risk of injury. The stretchers did not run any more miles than the non-stretched individuals.
However, this study also concluded that stretching after workouts reduced the risk of injury. The conclusion was made that stretching must be carried out when muscles are warm (and thus less resistant to being stretched out) to be protective.
In a similar stduy (2) 159 runners were instructed how to warm up, cool down and stretch effectively while a second group of 167 similar runners received no instruction at all. Over a few months, the injury rates of the two groups were identical so the instructed warm-up, cool-down and stretching provided no protective benefit.
However, other studies have found that stretching may be beneficial. A study of military recruits who practised a series of static stretches before and after training were compared to a control group who performed no stretches (3). The stretching group demonstrated a significantly lower rate of muscle-related injuries but no difference in the rate of bone or joint injuries.
In a review of the literature, Thacker et al (4) stated that “There is not sufficient evidence to endorse of discontinue routine stretching before or after exercise to prevent injury among competitive or recreational athletes”.
(2) van Mechelen W, Hlobil H, Kemper HCG, et al. Prevention of running injuries by warm-up, cool-down, and stretching exercises. Am J Sports Med 1993;21:711-19.
(3) Amoko et al. “Effect of static stretching on prevention of injuries for military recruits.”
(4) Thacker et al. “The Impact of Stretching on Sports Injury Risk: A Systematic Review of the Literature”. Medicine & Science in Sports & Exercise. 36(3):371-378, March 2004.