Running is a safe and effective form of exercise that results in endless amounts positive health benefits. There are often questions though on how someone should warm-up prior to the run and historically this has been a no-brainer to answer. Many of us were taught that you need to do a proper warm-up prior to running and that required us to thoroughly stretch the lower body prior to hitting the road or the trail. But does the evidence back this up? Does stretching truly prevent running injury or increase performance?
The short answer no. There have been a large number of reviews since the late 1990’s that attempt to answer this question and found that there is no reduction in injury risk with static stretching immediately before running. In fact, some reviews have suggested that there might be a slight increase in injury risk due to reduction in performance measures. Why the reduction? One theory is that stretching temporarily reduces pain with end of range positions and could cause us to overstretch without realizing during exercise. Further, authors suggest that static stretching doesn’t seem to help with running tasks since we don’t need to reach end of range positions, but might be more helpful when you need maximal flexibility (think gymnastics or dancing).
“there is no reduction in injury risk with static stretching immediately before running”
How does stretching affect running performance? Again, there isn’t great news for static stretching immediately before running. There seems to be a reduction in various measures of performance - speed, strength, jumping ability and endurance. Why are there potential reductions in performance measures? Stretching may temporarily reduce the stiffness of tendons in the lower body and some stiffness is actually advantageous for runners! Think of having a stiff versus a loose trampoline spring, which one would provide more bounce? Likely the stiffer the spring. Again a certain degree of tightness is actually helpful for running providing more spring and forward propulsion in runners steps.
“Think of having a stiff versus a loose trampoline spring, which one would provide more bounce?”
Well now the question becomes: what should we do prior to running? What is an effective warm-up? Doing some dynamic exercises may be more helpful in increasing blood flow to the muscles that are being utilized during running. This could be done using slow controlled mid-range movements such as squats, lunges, calf raises, high knees, butt-kickers, etc. Another effective warm-up is to simply go for a slow (sub-maximal) jog prior to going on your normal run. For example, if your normal pace is 5 minutes per kilometre, you could start with a short run at a slower pace - 6 minutes per kilometre - and then start at your normal pace. Always keep it simple, the most important thing is to get your body moving and warm prior to any exercise routine.
For all runners, very effective strategies that reduce the risk of injury come in the form of good training load monitoring and muscle strengthening exercise which has been written about in more detail here. Does that mean we completely discard static stretching? I would argue not. To be clear, the above recommendations are specifically for stretching immediately prior to running. There is reason to believe that having a general stretching routine is helpful for reducing injury risk to muscle, ligaments and tendons. One such protocol suggests stretching key muscle groups for 30 seconds at a time, which I believe is a good starting point if you are wanting to start a stretching program.