Flexibility is defined as the intrinsic properties of body tissues that determine maximal joint range of motion (ROM) without causing injury (1). Typically tests such as the sit and reach have been used to measure and assess athletes flexibility. Flexibility has been incorporated in the fitness world going back to the creation of the President’s Council on Physical Youth Fitness (2), and a recent study of personal trainers showed that a full 80% prescribe static stretching (3). However, should there be an emphasis on flexibility like there is? Does flexibility drive athletic performance?
The answer is no. Research has demonstrated that static stretching:
- Reduces vertical jump height (4)
- Causes neurological impairment (5)
- Puts the athlete at a greater risk of injury (6)
- Decreases dynamic strength of muscle (7)
- Doesn’t prevent injuries (8)
- Results in more severe injuries (9)
- Acutely reduces muscle force (10)
- Doesn’t correlate with athletic performance (11)
- Doesn’t determine who plays and who doesn’t (12)
Unfortunately, like many antiquated and outdated methods in the fitness world, static stretching has endured despite the overwhelming research showing it to be a poor choice. Notably, in several of the same studies, body composition and muscular strength WERE strongly correlated with athletic performance. The vast majority of athletes spend hours upon hours at practice, games, tournaments, and private lessons honing their sport skill. What most are missing though as they advance up the levels of their sport, is not some minute aspect of their mechanics they need to tweak, but the speed, power, and strength necessary to compete on the elite level. And to achieve that, they’ll need consistent, hard training that doesn’t rely on outdated fitness tropes like flexibility, but what actually gets results.
References
1. Holt J, Holt LE, Pelham TW. Flexibility redefined. In: Bauer T, editor. Biomechanics in Sports XIII. Thunder Bay: Lakehead University; 1996. p. 170-4.
2. Institute of Medicine. Fitness measures and health outcomes in yout. Washington, D.C.: The National Academic Press; 2012.
3. Waryasz GR, Daniels AH, Gil JA, Suric V, Eberson CP. Personal trainer demographics, current practice trends and common trainee injuries. Orthop Rev. 2016; 8 (3): 6600.
4. Rosenbaum, D. and E.M. Hennig. The influence of stretching and warmup exercises on achilles tendon reflex activity. Journal of Sport Sciences, 13, 481-490. 1995.
5. Hough, Paul A, Ross, Emma Z, Howatson, Glyn. Effects of Dynamic and Static Stretching on Vertical Jump Performance and Electromyographic Activity. Journal of Strength and Conditioning Research; p 507-512. March 2009.
6. Kokkonen, J., A.G. Nelson, and A. Cornwell. Acute muscle stretching inhibits maximal strength performance. Research Quarterly for Exercise and Sport. p 69, 411-5. 1998.
7. Knudson, D., K. Bennet, R. Corn, D. Leick, and C. Smith. Acute effects of stretching are not evident in the kinematics of the vertical jump. Research Quarterly for Exercise and Sport (Supplement). p 71, A-30. 2000.
8. Thacker SB, Gilchrist J, Stroup DF, Kimsey CD Jr. The impact of stretching on sports injury risk: a systematic review of the literature. Med Sci Sports Exerc. 2004; 36 (3): 371-8.
9. Konopinski MD, Jones GJ, Johnson MI. The effect of hypermobility on the incidence of injuries in elite-level professional soccer players: a cohort study. Am J Sports Med. 2012; 40 (4): 763-9.
10. Kay AD, Blazevich AJ. Effect of acute static stretch on maximal muscle performance: a systematic review. Med Sci Sports Exerc. 2012; 44 (1): 154-64.
11. Holland GJ. The physiology of flexibility: a review of the literature. Kinesiol Rev. 1968; 1: 49-62.
12. Shields CL, Whitney FE, Zomar VD. Exercise performance of professional football players. Am J Sports Med. 1984; 12 (6): 455-9.