You’ve likely heard that stretching is good for increasing performance. You’ve also likely heard that stretching inhibits performance. So which is it? The answer is not so much that one is inherently good or bad, but rather what element of performance is being assessed.
It wasn’t all that long ago that stretching was recommended before and after any sort of physical activity, and running certainly fell into this category. Then studies came out that stated stretching before a workout would diminish performance due to decreased levels of force production.
This focus of this post is to clear up some of this information to help educate you on this topic as it pertains to training yourself and clients, if applicable.
To understand how stretching ‘works,’ it’s important to be aware of two parts of a muscle, the Golgi Tendon Organ (GTO) and the Muscle Spindle. The main function of the GTO is to sense tension at the muscle/tendon junction and regulate muscle tension accordingly so injury does not occur to the muscle and its associated connective tissue.
Muscle spindles are located deep within a muscle. Muscle spindles sense change in muscle length as well as the range of change in length. Changes in length trigger the stretch reflex (also called myotatic reflex). The stretch reflex resists the increase in muscle length by causing a muscle to contract. The more rapidly muscle length increases, the stronger the stretch reflex is. Therefore, the primary function of muscle spindles is to protect the body from injury due to overstretching.
The goal of stretching is to minimize the stretch reflex so that a muscle can be lengthened.
The combination of a muscle and it’s associated tendon is termed the ‘muscle-tendon unit.’ The stiffer the muscle-tendon unit is, the greater the elastic response. In other words, the greater the stiffness of the muscle-tendon unit, the greater the potential energy source is. This is the genesis of the ‘pre-stretching is bad’ theory.
However, if an individual’s flexibility and range of motion does not match the degree of flexibility required for a particular movement, performance decreases and the potential for injury increases. Therefore, the amount of flexibility and range of motion in a particular area should match the amount of flexibility required for the activity being participated in. Substantially more or less flexibility than is required will negatively impact an individual.
TYPES OF STRETCHES
There are three primary types of stretches that one can do themselves:
Static: An individual performs and holds a stretch at the end range of motion (ROM).
When holding a stretch for a relatively long period (> 40 seconds), the muscle spindles become accustomed to the new increase in length and reduce the signals sent to the spinal cord to tell the muscles to contract.
Dynamic: An individual moves a body part at a controlled speed through a ROM that mimics the motions performed while running.
Ballistic: Similar to the dynamic stretch, but the movement is done rapidly with the goal to stretch past the current ROM limit. Due to the speed with which a ballistic stretch is executed, the stretch reflex is triggered and therefore greatly limits the ability of a muscle to stretch. This stretch is not recommended.
Myofascial Release (MFR) is commonly used to describe a process in which tight muscles have compression applied to them to ‘release’ tightness, thus restoring proper function. Myo is a prefix that means muscle and fascial relates to the fascia, which is a thin, web-like sheath that covers muscles. Therefore, the term myofascial release pertains to the reduction of tightness and restrictiveness of muscles and fascia.
A common tool used by runners for myofascial release is the foam roller. A widely accepted practice surrounding foam rollers is that the more it hurts, the better it is working. This could not be further from the truth. The reality is that too much compression over stimulates the muscle spindles (i..e, nervous system) and causes the muscles to shorten in response as a protective measure against injury. Additionally, too much compression can damage muscles and connective tissue on a cellular level (fibroblasts) and actually increase inflammation rather than reduce it. Just because pressure is applied to a tender area via a foam roller or by other means, the pain and tightness will not necessarily go away. In some cases and as noted above, it can actually make it worse as excessive pressure from the roller can create trauma.
In relation to the thought that pre-stretching reduces force production and therefore performance, when done properly, foam rolling has been shown to decrease muscle and fascia tightness but without a decrease in force production.
APPLICATION TO DISTANCE RUNNING
A lot of the studies citing a decrease in force production via pre-stretching are examining maximal force production, which is not typical for distance runners. Therefore, it could be theorized that pre-stretching is not as much of an issue for distance running as it would be for sport disciplines that predominately require short, maximal efforts (ex: sprinting).
FORCE PRODUCTION vs. RANGE OF MOTION
The discussion of whether or not pre-stretching reduces force production is not all that relevant to distance running. By far, the more important aspect in regard to stretching for distance runners is proper range of motion (ROM). Even if pre-stretching does reduce force production, if a runner does not have adequate ROM, any increase in force production will be negated due to the increased chance for injury and performance reductions due to a lack of range of motion. Even sprinters and athletes in sports that require maximal force production still need to be able to move a limb through it’s full ROM.
As an example, let’s say that a runner has really tight calves (gastrocnemius/soleus). Ankle joint stiffness plays a role in running efficiency – the tighter the calf/Achilles, the more energy is stored when the ankle flexes, and the more energy is released (read: stronger foot push-off) when the ankle extends. Therefore, this runner likely stores and releases a lot of energy from the calf/ankle. However, unless they have full ankle joint ROM, they likely run with reduced hip extension and therefore a compensated running gait that reduces their performance. Lastly, if they do fully extend through their hip with reduced ankle ROM, they place themselves at a high risk of injury.
Therefore, as a running coach, my first concern of a client is range of motion and secondarily, energy return.
Being able to run with full ROM is important for both performance and injury prevention. Therefore, if you or a client has limited ROM at one or more joints, working towards attaining full ROM is strongly advised. It’s not a bad idea to work to increase force production, but it must only be done after full joint ROM is established.
Rick Prince is the founder of United Endurance Sports Coaching Academy (UESCA), a science/evidence-based endurance sports coaching education company that certifies running and triathlon coaches.
To learn more about our Running Coach Certification and to get a code for $50 off, click here!
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