Many athletes ask me about strechings. When to make them ? Have they a real interest or do they avoid stiffness ? Do they reduce the risk of strains or wounds ?
What do the scientific literature have to say ?
1. The strech, a necessity ?
As a reminder, Larousse/the dictionnary defines streching as « the fact of strech ». It’s a muscular elongation. [1]
The appearance/occurrence/onset of streching in athletic’s training has been a progress. Actually, athletes have learnt to better know themselves, their body and their muscles. So this post is not about questioning the interest of streching but bringing a scientific perspective about these last things, even if it means « killing off » preconceptions. Initially, streching was a technique which aimed to increase range of motion and was gradually attributed to wounds’ and strains’ prevention.
2. When to strech ? Do you have to strech after training ?
2.1. Streching : « useful » to prepare the muscle to the effort ?
Streching is aimed to prepare muscles to training or competition. Therefore, it has to increase gradually muscles’ temperature by increasing blood flow. Alter demonstrates that strechings cause interruption on blood flow, which causes an inverse affect/the opposite to the desired effect. [2] Two more studies [3] conclude similar results. Streching would be inefficient on increasing muscular temperature and would cause a muscle cooling.
Finally, streching would not permit a muscular training.
2.2. An other preconception : streching to prevent wounds ?
Since 1993, many studies prove the oppposite [5] [6] [7] [8]. One study even shows that they could increase the risk of wounds. [9]
In 1999 and 2000, Shrier discusses an antalgic effect of streching. [7] [10] The other explanation lies on streching’s tolerance. This last would inhibit the strech reflex, a natural and protective reaction against heavy/brutal strechings which serves to protect the muscle by contracting it. Strechings also provide analgesia by moving the pain threshold, which can be dangerous and promote/encourage tears or other injuries such as strains.
One study shows that passives’ strechings impose muscle’s tensions equivalent to maximal muscular tensions [3], which can create muscular damages.
Finally, streching would not prevent from wounds.
2.3. Streching to improve performances ?
Strechings had a negative effect on athletics performances. Actually, many studies show a negative action on speed [3] [11], contraction force [12], endurance [13] [14] [15] [16].
To provide an explosive force, as in the jump or the sprint, muscle should be stiff. However, strechings decrease this stiffness and the tendinous fibers. Likewise, streching can have an « un-coordinating » effect on agonist-antagonist muscles.
Before sport and during training, strechings seem inefficient for the preparation of the body to the effort, the prevention of wounds and even dangerous for the athlete. However, a shade need to be made for sports requiring important/large/major amplitudes with high flexibility, such as gymnastics, dance, ice-skating… For those sports, strechings should occur at the midpoint of the training.
3. Streching after sport ?
After sport, it’s common in athletes’s speech that strechings would decrease stiffness and improve muscular recovery.
3.1. First, what cause stiffness ?
Stiffness are muscular’s « micro » injuries resulting by an increasing of plasma concentration of creatine kinase (first marker of muscular damage). Unlike preconceptions, stiffness are not caused by acid lactic’s accumulation.
Studies are unanimous and don’t show that strechings decrease this plasma concentration [17] [18]. A summary of the studies about « stiffness and strechings » reveals that there is no significant impact of strechings as well at 24h, 48h or 72h after the effort [19].
We may also add, as seen previously, that passive muscular streching doesn’t allow a right vascularization and leads to a poor drainage of muscular’s wastes.
3.2. Strechings and muscular recovery
Just after have been requested, muscles stay in shortened position. This shortening is caused by a blockage of actin-myosin’s bridges that compose muscular fibers. An immediate streching is then discouraged because of the risk of muscular injuries or of worsening of these injuries. It is recommended to strech 30min after sport to remove and release the lasts blocks and stiffness. This is true if there is no competition in the next few days. [20] [3]
3.3. An interest/a benefit anyway of the streching ?
Of course, streching has an interest to win in flexibility and so elongate muscles. But this work can be done at the end of a non intensive training (because streching could increase injuries)
The streching between trainings should be prioritised. It is advised to do passive’s strechings and « contracted-relaxed » because these are good technics to gain range of motion and improve muscular capacity on a long-term but you have to focus on areas that present a low amplitude.
Conclusion
Before sport, scientific literature doesn’t reveal an interest for streching. Streching can damage the muscle, cool it and also decrease its strenght’s and speed’s capacity. However, a streching is essential [21] and should last at least 20 minutes.
Similarly, after an intense effort, it is discouraged to strech because there is a risk to damage the muscle. However after a mild effort, the streching type « contracted-relaxed » can be done with kindness to inhibit the receptors and have a feeling of well-being. Passive strechings at the end of a training must be done 30min after the effort or just after the shower when the muscles are cooled. Don’t strech yourself if you plan, in the next couple of days, a competition or any other speed activity where performances are expected.
Apart from that, streching participates to the proper functioning of the joints removing the blockages, allowing to maintain and to improve the flexibility. Finally, analgesic effect gives a feeling of well-being.
The 12 elements to respect for streching in sport
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Don’t strech a cold muscle
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Don’t strech a stiffness or painful muscle
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Never strech a damaged muscle
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Don’t resume streching without the opinion of a healthcare professional (doctor, osteopath, physiotherapist…)
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Strechings have to be done slowly, in synchronization with breathing
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Don’t strech an isolated muscle but a muscular chain
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A strech doesn’t have to hurt, you must not exceed your pain threshold which represents streching’s limit of the muscle : « know how to listen to your feelings »
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Strechings must be done in an enabling environment to relaxation.
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Never strech yourself in a cold environment ; make sure that you have a good hydratation before, during and after streching.
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Never strech right after effort but wait 30 minutes.
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Don’t strech after effort if a competition is scheduled in a couple of days.
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To know how to strech properly : you should take advices from a healthcare professional
Bibliography
[1] Larousse, "Dictionnaires de français," [Online]. Available: http://www.larousse.fr/dictionnaires/francais/%C3%A9tirement/31482. [Accessed 25 11 2015].
[2] A. M. J., Science of flexibility, 1996.
[3] K. A. Wiemann K., "Die Bedeutung von Dehnen und Stretching in der Aufwärmphase vor," Leistungssport, vol. 4, pp. 5-9, 2000.
[4] J. ROBE, "L’échauffement en gymnastique artistique (1ère partie)," Clés pour la forme, 2005.
[5] H. R. K. J. Pope R, "Effects of ankle dorsiflexion range and pre-exercise calf muscle stretching on injury risk in Army recruits," Aust J Physiother, vol. 3, no. 44, pp. 165-172, 1998.
[6] H. R. K. J. G. B. Pope RP, "A randomized trial of preexercise stretching for prevention of lower-limb injury," Med Sci Sports Exerc, vol. 2, no. 32, pp. 271-277, Feb 2000.
[7] S. Ian, "Stretching before exercice does not reduce the risk of local muscle injury : a critical review of the clinical and basic science literature," Clin. J Sport Med, vol. 4, no. 9, pp. 221-227, Oct 1999.
[8] K. R. S. A. Zakaria AA, "Effects of Static and Dynamic Stretching on Injury Prevention in High School Soccer Athletes: A Randomized Trial," J Sport Rehabil, vol. 24, no. 3, pp. 229-235, 24 Aug 2015.
[9] D. A. Lally, "Stretching and injury in distance runners," Medicine and Science in Sports and Exercise, vol. 5, no. 26, 1994).
[10] G. K. Shrier Ian, "Myths and truths of stretching,," The physician and sportsmedicine, vol. 28, no. 8, Aug 2000.
[11] B. T. W. N. Ye X, "Influence of prolonged static stretching on motor unit firing properties.," Muscle Nerve, 17 Sept 2015.
[12] J. N. A. G. a. A. C. Kokkonen, "Acute muscle stretching inhibits maximal strength performance," Research Quarterly for Exercise and Sport, vol. 69, no. 4, pp. 411-415, 1998.
[13] J. N. A. G. &. A. D. A. Kokkonen, "Acute stretching inhibits strength endurance performance," Medicine and Science in Sports and Exercise, vol. 5, no. 33, p. Supplement abstract 53, 2001.
[14] B. K. C. R. L. D. S. C. Knudson D, "Acute effects of stretching are not evident in the kinematics of the vertical jump," Journal Strength Conditioning Resaerch, vol. 1, no. 15, Feb 2001.
[15] N. A. S. B. Cornwell A, "Acute effect of stretching on the neuromechanical properties of the triceps surae muscle complex," Eur J Appl. Physiol, vol. 86, pp. 428-434, 2002.
[16] W. M. M. F. C. R. Church JB, "Effect of warm-up and flexibility treaments on vertical jump preformance," Journal Strength Conditioning Research, vol. 3, no. 15, pp. 332-336, Aug 2001.
[17] S. J. Buroker K.C., "Does post exercise static stretching alleviate delayed muscle soreness ?," Physician and sport Medecine, vol. 17, no. 6, pp. 65-83, 1989.
[18] J. Wessel and -A. Wan, "Effect of stretching on the intensity of delayed-onset muscle soreness," Clinical journal of sport medicine, pp. 83-87, Apr 1994.
[19] G. M. Herbert RD, "Effects of stretching before and after exercising on muscle soreness and risk of injury: systematic review," BMJ, vol. 7362, no. 325, p. 468, 31 Aug 2002.
[20] G. Cometti, "1ère partie :« Intérêt des étirements avant et après la performance »," Les limites du stretching pour la performance sportive, p. 7.
[21] G. Cometti, "Newsletter N°6," Centre d'Expertise de la Performance, Oct 2012.
Septembre 03, 2016 | Delaville Arnaud - Ostéopathe DO