The Skinny on Stretching

Whether new or experienced, young or old, there are questions, misconceptions, and variable methods in preparation for endurance activity.  So with all of the information out there, what are best-practices when it comes to the warm-up and stretching?

Static stretching

To start, let’s clear up some misconceptions.  Static stretching (or low-load prolonged holds) do not put your muscles, tendons, or joints at risk.  They are safe movements that, when used correctly, can effectively maintain or increase muscle length.  So, if you are using static stretches prior to running or other endurance activity and that has worked for you; while possibly not optimal, there is no risk in continuing this trend.

Dynamic Stretching

Next, dynamic stretching is not the same as ballistic stretching.  A dynamic stretch is a controlled active movement that takes the muscle through its activity related range of motion, whereas, a ballistic stretch forces tissues through a greater range of motion with bouncing or forced pressure at end range.  Performance of a dynamic stretch does not simply mean taking a static stretch and adding in a bounce to prevent a static hold.   A dynamic stretch is performed by actively taking the muscles or joints through a range of motion that is required for the activity.  An example would be the use of lunges with rotation.  Due to the hip extension and lumbar rotation requirement of running, an effective way to warm up those components of the motion is to perform a lunge with a rotation towards the opposite hip.  This, performed repetitively, allows the hip flexor musculature to appropriately lengthen when the leg travels behind the body during the running cycle.

Why stretch?

So, with that out of the way, why stretch?  Traditionally, the reasoning behind stretching has focused on injury prevention, and more recently, on performance enhancement, yet, the research has not consistently supported these claims.  First, when it comes to injury prevention, a recent comprehensive review of the literature suggests that stretching exercises, whether before or after, does nothing to decrease the relative risk of injury.(1)   This is in agreement with prior reviews of the subject.(2) Additionally, stretching does not appear to have an effect on muscle soreness brought on by exercise.(3)  More important would seem to be overall dosage of the exercise activity, as well as strength and proprioceptive training.

Static, No? Dynamic, Yes?

As for performance enhancement, dynamic and static stretches (in addition to other types of stretching), have been examined to determine their relative impact on performance of activity.  What has been found, is that the negative effects of static stretching (which are often cited as a reason not to stretch before activity), are related to activities of power, strength, agility, and speed.(4)  There is evidence that static stretching has a negative effect on endurance activities, however, due to the populations evaluated and overall paucity of studies, the strength of evidence is not yet strong.(4)  Dynamic stretching, on the other hand, has shown positive effects on activities of power, strength, agility, and speed, while performance of endurance activities has shown no change from a dynamic warmup.(5, 6)     So, overall, what we can glean from this is that conventional wisdom and current practice of dynamic warmup before activity and static stretching for cool down may be little more than old habits dying hard and taking the support for dynamic warmup in the context of athletic activity (ie. sports) and translating that to endurance activity.

Warm up with stretching at least

So, the bottom line is that, whereas many of us may or may not use stretching before or after endurance activities, there really is limited support for their use in this context.  The benefit of stretching may seem more intuitive and common sense, however, the evidence is sufficiently lacking to support its use in the endurance athlete.  That being said, static and dynamic stretches are safe, and while they may not be useful in terms of injury prevention, or performance enhancement, they may be useful to generally prepare for activity or for other, yet to be determined, reasons.  The best support for the use of stretching prior to a run, swim, or bike session may simply be that it is a functional warmup and a way to prepare the muscle for activity.  Conversely, if preparing for a strength or power workout, a soccer game, or a track meet, the evidence does support the incorporation of a dynamic warmup prior to activity.

Hopefully this helps to dispel some of the myths regarding the use of stretching and stay tuned for more on the use of strengthening and plyometrics to prevent injury.  Happy training!