Any discussion around stretching before exercise among a fitness crowd is sure to garner some strong opinions.  Those opinions range as far as:

Stretching prevents injuries–>Stretching doesn’t matter.
Stretching  improves performance–>Stretching makes you weaker and slower.
Stretching makes you more flexible–>Stretching doesn’t change muscle length.

Should you stretch before exercising?  Such a simple question…and why are we all so divided on the conclusion?

It’s important to have some context to understand how and why the pendulum has swung so drastically in the past several decades.

In the 1980’s and 90’s research demonstrated static stretching (sustained stretches held in a position) done immediately before intense exercise resulted in a diminished performance output.  This was ground breaking, and further studies in  support of this narrative continued to build momentum.  It was found across several studies that the average performance decrease (speed, strength or power) was about 3-5%.  Seemingly small, but in competitions won by the slimmest of margins, could make or break an athlete.

By the 2000’s if you were looking to maximize explosive power, such as sprinting, jumping or lifting and you were caught static stretching prior to your event, you would likely get a tongue lashing for doing it all wrong.  Static stretching was essentially vilified.  The pendulum had swung in full force away from static stretching towards dynamic warm ups.  Dynamic warm-ups warm up tissue through progressive movement building towards the movements required of the exercise.  It often involves a combination of basic strength, balance, co-ordination/agility and mobility work.  Essentially it’s warming up through movement, instead of holding positions.

The effect wasn’t entirely wrong.  Dynamic warm-ups proved to be a superior approach to preventing acute muscle injuries such as hamstring or groin strains.  It also proved to be superior in maximizing tissue blood flood resulting in improvements in power output.  The warm up plan was certainly better off with a shifting emphasis towards a dynamic warm up.  This should be the centrepiece of your pre exercise plan.

But the disdain towards static stretching was unwarranted.  Recent research has demonstrated that only trivial negative side effects to strength and power occur if the accumulated stretching duration does not exceed 60 seconds.  Most professional athletes generally stretch for around 12-17 seconds per muscle group on average, however many research studies required the participants to stretch for more than a minute per muscle group (often as high as 3-4 minutes!).  In addition, research often required prolonged stretches, immediately followed by the variable being tested.  This seldom happens in the real world as stretching will often be followed by further warm up or some time lag before the competition starts.  Essentially the research methodology did not align with how stretching was being utilized in the real world.

A 2018 study by Blazevich et al   performed a more real world stretching methodology using a randomized cross-over design to test 5 second static stretching, 30 second static stretching, dynamic stretching or no stretching embedded within a full warm up.  The full warm up included a low intensity warm up, one of the 4 test conditions and was followed up by a specific practice progression to maximum intensity.  In the end, no effect was observed on the test condition with respect to vertical jump, sprinting or a change of direction task.  Essentially none of the static stretching or dynamic stretching conditions impacted performance.  The participants however did feel like they were more likely to perform better when any of the stretching conditions was part of the comprehensive warm up.

The simplest argument in support for stretching before exercise is the increases in range of motion it affords to the related joints.  There is an improved capacity to move through said range of motion if it has been stretched prior to exercise.  (This can happen with a dynamic movement of course as well).  However static stretching may provide an option to explore and prepare for more extreme ranges of motion.  Think of shoulder flexibility for a throwing athlete or hip mobility for a sprinting or jumping athlete.  Changes in range of motion from short hold static stretches (<60 seconds) seem to be related to increased tissue capacity and not actual changes in tissue architecture.  As an aside, long duration (60-180 second), higher frequency (5 days a week) stretches are required to affect change in tissue length/structure.

But does an increase in range of motion from pre-exercise static stretching prevent injuries?  Quite frankly this challenging domain of research which is inconclusive on this important point.

One prominent stretching researcher, Anthony Blazevich from Edith Cowan University in Australia, has found that pre-exercise stretching allows the muscle to exert more force when at longer lengths.  Considering most muscle and tendon injuries occur when the muscle is being stretched vigorously, there would seem in principle to be some injury prevention potential here.

The psychological benefits of static stretching cannot be ignored as well.  Many people subjectively feel more ready to exercise if they have done some static stretching.  That in and of itself is reason enough to stretch before you hit it.  Preparing the mind is just as important as preparing the body for what’s to come.

So where does that leave us, should you stretch before you exercise?  Ultimately if stretching feels good for you before any exercise session, you should proceed with the confidence that it is not the performance sucking devil it has been advertised to be.

Our recommendation for a warm up order if you want to incorporate static stretching before exercise:

-general light intensity movement to increase blood flow for a couple minutes
-static stretching <60 seconds per muscle group
-dynamic warm up catered to the movement demands of your exercise/sport/training session

Overall, our evaluation of personal experience, clinical experience and the scientific literature says stretch away!  And tell all the stretching haters to go away (or to read this article).