Stretching has long been advised by running coaches to help increase performance and decrease the chance of injury. This post will take a look at the whether this is sound advice.
At the most basic level, the goal of stretching is to increase the range of motion (ROM) of a joint. Therefore, if an athlete does not have the appropriate amount of range of motion for a particular joint, stretching is likely a good idea. Keep in mind that the appropriate range of motion is based on the joint, as well as the sport. For example, the appropriate ROM of the hip joint for a gymnast is much greater than that of a runner, cyclist or triathlete. This is an important point because many athletes believe that the more ROM an individual has, the better. How many times have you heard that being able to touch your toes is a sign of ‘good’ flexibility? Based on this thought process, being able to perform a split would be ideal for runners. This thinking is not asinine because we are conditioned from a young age to believe that the more flexibility one has, the better their fitness and overall conditioning is (remember the ‘Sit and Reach’ test?).
FUNCTIONAL RANGE OF MOTION
As noted above, the correct range of motion of a joint(s) is largely based on the sport or activity being performed. In respect to running and more specifically, the legs – hip extension is an important performance factor. Therefore, having enough ROM to allow for proper hip extension to occur is beneficial for runners, while having too much ROM is detrimental.
In this sense, you can see that the ideal ROM of a joint exists at the top of a bell curve. Too much or too little ROM will decrease performance and may increase the chance for injury.
LENGTH – TENSION RELATIONSHIP
One of the more common misnomers is that the goal of stretching is to get a muscle as ‘loose’ as possible. As mentioned above, the goal is to increase the ROM of a joint – not to ‘loosen’ a muscle. In contrast, a ‘tight’ muscle has historically been viewed as bad, primarily because it is associated with a limited amount of ROM.
However, the goal of an athlete and especially a runner is to have a tight muscle(s), while still being able to move a joint through the proper range of motion. Let’s look at the Achilles tendon unit, which is made up of the calf muscles and Achilles tendon. The ankle joint is a source of energy for a runner, as this is where the ‘push-off’ aspect of the stride comes from.
A good example of the Achilles tendon unit (or any muscle-tendon unit) is a rubber band. If the rubber band is too short, the ROM will be limited and if the ROM is forced, the rubber band could snap. Conversely, if the rubber band is too long, the tension on the rubber band will be minimal to non-existent when pulled to a set point. This will greatly minimize the potential energy stored in the rubber band and in regard to the Achilles tendon complex, it greatly reduces force production during the ‘push-off’ phase of the gait.
- The goal of stretching should be to increase ROM of a joint, not to make a muscle as loose as possible.
- The correct ROM of a joint should be dictated based on the ROM necessary to perform an activity (i.e., running).
- Too much or too little ROM of a joint will likely decrease performance.
If stretching before running feels good, go for it, but it should be done minimally. However, a warm-up jog that warms up the muscles is likely more beneficial. Myofascial release (i.e., foam rolling), has been found to decrease muscle activation (tightness), while not negatively impacting force production prior to exercise.
Stretching post-run is likely more beneficial than stretching pre-run, but as noted above, the stretches should only be done to the degree of the required sport-based ROM.