Stretching does not always favor the performance or recovery!

We often hear that it is very important to stretch before and after exercise in order to be more efficient, to reduce the risk of injury, and shorten the recovery time. So how many times have we waited, "I have aches ... It's normal, I'm not quite stretched after my race! ".

What is it really?

The stretch are made general:

Before an effort : the purpose of warming up, preparing the muscle to make the effort and thus, ultimately , to improve performance.
After an effort : in order to recover faster, reduce the duration and intensity of aches, and therefore, ultimately , risk of injury.

Check what says the scientific literature.

Stretching and Performance:

A study (1) conducted a meta-analysis on the relationship between stretching and performance concluded that, on 23 articles reviewed, 22 suggest that there is no benefit to stretch before an isometric force effort or dynamic, or on a test of jump. Sometimes, prior to a stretching effort results in a decrease in performance (speed effort or explosive strength). 1 only suggested improvement on endurance performance, but that was contradicted by other 3 studies.

However, a more recent meta-analysis (2) concluded that warming should include a drawing process to 15 minutes before exercise.

These differences show that the subject of stretching in the sports world is still highly controversial.

In France, Cometti achieved remarkable work of synthesis (3) on the question of stretching, and pushed the athletes and coaches to reflect on their practices by integrating the latest findings. However, it is clear that nothing is yet decided, and that the question of stretching is unusually complex. The sometimes contradictory conclusions reached in numerous studies are mainly due to the variety of protocols implemented in experiments (different forms of stretching, sports or different types of stress ...) which make it impossible to generalize.

Concretely, keep in mind that:

Stretching does not increase muscle temperature, so they are, in isolation, poor way to prepare the muscle to the effort.
They tend to reduce performance on explosive effort (jumping and sprinting).

but:

When included in a warm-up phase, they can limit the risk of injury, and will not negatively impact the performance of certain types of exercise (endurance).

Stretch and recovery:

A study (4) found that stretching before or after exercise did not reduce muscle pain.

It even happens that the recovery time is increased by a stretching session following an explosive force, for example. If the effort has generated micro-tears in muscle, stretching tends to worsen, making the repair more difficult.

In this case, Cometti (3) advocates active recovery, increasing the drainage of "metabolic waste" produced by muscle, without adding any micro-fissures.

When considering the issue of soreness following a force, and their possible reductions with stretching, keep in mind that each researcher from a definition of the concept of "curvature" to it clean. Thus, the conclusions drawn after the various articles are hardly comparable, which explains the observed disparities.

To conclude, in view of the balance profits / risks associated with stretching performed after exercise, it does not seem appropriate to promote their use in order to reduce muscle soreness and recovery time. However, all this is to modulate depending on the sport and the type of effort.

Conclusion:

Thus, if the practice of stretching as a tool heating or recovery to improve performance and reduce muscle soreness is not proved, the fact remains that there is a global consensus on the need stretching for muscle health.

A regular practice of stretching, without being associated directly before or after exercise improves many physiological and mechanical aspects of the muscle, which promotes performance and reduces the risk of injury over the long term (5). Thus, on 9 studies examining the effects of regular stretching (without associating them with an effort), 7 concluded it was beneficial, and 2 it had no impact. None has shown any adverse effects.

MUST therefore stretch, but preferably before or after exercise. We include in the week stretching sessions, which do not interferont with the workouts, but will maintain the mechanical properties of the muscle.

1. Shrier, I. (2004). Does stretching Improve Performance ?: a systematic and critical review of the literature. Clinical Journal of Sports Medicine, 14 (5), 267-273.
   2 Woods, K. Bishop, P. & Jones, E. (2007). Warm-up and stretching in the prevention of muscular injury. Sports Medicine, 37 (12) 1089-1099.
2. http://grenet.free.fr/fjtreize/Entraineurs/Documents/Etirements_Cometti_annote.pdf
3. Wessel, J., & Wan, A. (1994). Effect of Stretching on the intensity of delayed-onset muscle soreness. Clinical Journal of Sport Medicine , 4 (2), 83-87.
4. MacAuley D, Best T, eds. Evidence-Based Sports Medicine . London: BMJ Publishing Group; 2002: 97-116