Stretching ? of course… but when ?

Since our childhood, coaches have been making kids stretch before any physical activity. As I played hockey on a competitive level for 10 years, I can confirm that our coach used to make us stretch only before a practice or a game because our bodies were ”cold”. Before every practice, we had about 10 minutes of stretch before we began. As we grow older and create our own opinion about things, we end up questioning ourselves on when the stretching exercises should be properly performed. Is it better to stretch before of after exercises but also why… There is no correct answer to these questions existing in actual the literature. Further research need to be done, but we are able to see a certain tendency in today’s literature.

First of all, we can ask ourselves what exactly is a stretch. By definition, a stretch is a movement that creates more space between the insertions of the muscle to put that muscle under tension. Each muscle has two parts: the muscle belly, which is the part that can contract, and the tendon which is composed by collagen fibres. That second part does not contract but is the link between the muscle belly and the bone. When we maintain a gentle stretch on a muscle, there is a relaxation of the Golgi Tendon Organs (GTO) which are located in the muscle belly. On another hand, when we do a quick stretch on a muscle, that stimulates the neuromotor fibres within the muscle belly, which provokes a stretching reflex. This last reflex is used to help contracting a muscle that is very weak or inhibited. If we are facing a tensed muscle or a spasm, a continuous gentle stretch would help recover the muscle’s full length, prevent retraction, and reduce muscle tension. When we practice sports, continuous stretches are often used and we will focus on this type of stretch for today.

Now we will consider when the continuous stretching should be performed. As mentioned, in some sports it is common to stretch before beginning the activity. Some of the older beliefs lead people to believe that stretching before an activity would reduce the risk of injuries. According to various researches, it would not be recommended to stretch before performing an activity. Indeed, according to a meta-analysis (Gremion, 2005), the stretches do not have any protective effects if performed before the exercise. To use stretching exercises prior to an activity does not reduce the risk of injury, bone lesions or soft tissue injuries. Several things have a strong correlation with the risk of injury, for example individual shape, age or general stiffness.

A study from Kovacs even demonstrated that a stretching exercise performed before an important effort requiring strength, speed, and endurance, can reduce up to 30% of the athlete’s performance. The decline of the performance can last up to 60 minutes after stretching (Kovacs, 2006). It is important to look at these results with an open mind; for an injured person it may be beneficial to stretch before an activity. In brief, a general warm up before performing an exercise is a prerequisite. That warm up can be composed of lightweight ballistic stretching, for example a soccer player who balances the leg from front to the rear to warm the muscles. In 2012, there are still many people that aren’t able to differentiate a warm up from stretching.

Then, one can question the relevance of performing a stretch while performing an activity. My researches on this issue remain inconclusive. There is currently no research which proves the beneficial or adverse effects of stretching during an exercise. I, as well, do not recommend intense stretching while performing an activity. It is possible to assume that the answer to the question should we stretch while performing an activity is similar to the previous one on stretching before the exercise. The stretch creates, among other things, a higher risk of injury through a misalignment of the sarcomeres fibres and a high risk of muscle ischemia. However, again, a person who has an injury could perform of light stretch while exercising to maximize the rehabilitation.

Also, in several sports, stretching is neglected after the activity. One realizes in seeking through literature that there is more evidence on the benefits of stretching after an activity. Thus, it is recommended to always stretch after a physical exercise. It is important to stretch the muscles within 15 minutes after the end of the activity in order to leave enough time for the motor units to reduce their activity. The stretches should last between twenty to thirty seconds and be repeated three to six times per muscle group. This will allow the muscles, which shrink sometimes from strengthening, to regain their full length (Fortin, 2007). A stretch which lasts for less than 20 seconds is considered a loss of time. With less than twenty seconds, the components of the muscle do not have the time to deform and stretch to their full length. On the other hand, there would be no additional benefits if we maintain a stretch for a minute compared to thirty seconds. Therefore, stretching helps to keep the flexibility of the muscle, to reduce tensions and to relax an individual. It is also important to note that the literature does not show that stretching will prevent pain and stiffness post-exercise.

Finally, one has to consider that the level of controversy is still high in the literature regarding the benefits of stretching and when it should be performed. Stretching exercises have an important role in maintaining the optimum length of a muscle or a group of muscles. When a person does not stretch or stretches poorly, he might develop several injuries, such as chondromalacia patella, tendonitis, plantar fasciitis, muscle tears, etc. Remember that many injuries are due to muscle imbalance and that they can be prevented by using a proper program mixing strengthening and stretching.

Anick Bernier

Physical therapist

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