Stretching Doesn’t Do What You Think It Does
A Physical Therapist’s Perspective
Everyone knows that stretching is good for you, but most people are wrong in WHY they think it is good for you. As a PT and frequent gym-goer, I often hear that stretching is good because it helps lengthen the muscles. This is completely wrong. I think it is time to debunk some of the myths surrounding stretching. After reading this page, you will have a better understanding of what does and does not happen when you stretch. You might even be able to enlighten those around you in yoga class or at the gym.
What Stretching Doesn’t Do
1) Stretching does not yield an increase in muscle length.
2) Stretching before physical activity does not reduce the risk of injury.
3) Stretching does not reduce exercise-related muscle soreness.
What Stretching Does
1) Stretching increases joint range of motion (ROM).
· Studies have consistently shown that regular stretching can increase the range of motion a joint has. Studies have also shown that this increase is not due to a change in the passive mechanical properties – meaning the muscle isn’t getting longer! For example, if you consistently stretch the hamstring muscles, you will be able to reach farther down to the floor, but not because the hamstring muscle has increased its length. You get closer to the floor because of an increased neurological tolerance to stretch. This means that the nerves in your body get used to the stress placed throughout the stretched muscle, which allows you to push further into the tension (thus improving ROM).
2) Stretching improves muscle and tendon health.
· Studies have shown that stretching prior to physical activity does not reduce the risk of injury. However, some studies have shown that regular mobility training over the course of several weeks can reduce the rate of injury to musculotendinous structures (meaning the tendon or muscle itself). If you hope to reduce your risk of injury, you will likely need to do consistent, regular stretching over time (approximately 3-6 weeks), not just prior to exercise. Additionally, several studies show that dynamic stretching is better at improving ROM and reducing injury than static stretching.
3) Stretching can only mask the level of muscle soreness following exercise
· Delayed onset muscle soreness, aka DOMS, is the feeling of pain or stiffness that you get after a recent bout of physical activity. When you are working out, your muscles are placed under stress that causes microscopic damage and tearing. These microtraumas subsequently start the body’s repair process, where biochemical inflammatory markers are increased as the muscle attempts to heal itself. Yes, this means that your childhood coach telling you that soreness was due to lactic acid buildup was wrong. The process of muscle fiber damage and repair leads to soreness that often lasts 24 to 48 hours. Studies have shown that stretching has no impact on the DOMS process and cannot speed it up. In fact, there is minimal literature stating that we can reduce DOMS in any way. However, studies have shown that stretching can temporarily reduce the amount of pain you experience and, therefore, may help in the short term.
Bottom Line:
· Stretching can improve your range of motion by increasing the body’s tolerance to tension being placed on the stretched area. It does not leave you with a longer muscle.
· Stretching before exercise does not reduce the risk of injury during activity. However, some studies show that regular mobility training may decrease the risk of musculotendinous pathology.
· Stretching does not improve muscle soreness (DOMS) following strenuous exercise.
· Dynamic stretching may be more beneficial than static stretching. Static stretching should not be performed when the athlete is cold or prior to activities.
Disclaimer: The information listed on this page is not to be used as medical advice. If you have any questions or concerns regarding stretching, mobility or musculoskeletal pain please seek out professional attention.
References:
1) Ben, M. and Harvey, L. A. “Regular stretch does not increase muscle extensibility: a randomized controlled trial.” Scandinavian Journal of Medicine & Science in Sports, (2010) 20: 136-144.
2) Behm DG, Blazevich AJ, Kay AD, McHugh M. “Acute effects of muscle stretching on physical performance, range of motion, and injury incidence in healthy active individuals: a systematic review.” Appl Physiol Nutr Metab. 2016 Jan; 41(1):1-11. doi: 10.1139/apnm-2015-0235. Epub 2015 Dec 8.
3) Dupuy O, Douzi W, Theurot D, Bosquet L, Dugué B. “An Evidence-Based Approach for Choosing Post-exercise Recovery Techniques to Reduce Markers of Muscle Damage, Soreness, Fatigue, and Inflammation: A Systematic Review With Meta-Analysis.” Front Physiol. 2018; 9:403. Published 2018 Apr 26. doi:10.3389/fphys.2018.00403
4) Masatoshi Amako, Takaaki Oda, Kazunori Masuoka, Hiromichi Yokoi, Paolo Campisi. “Effect of Static Stretching on Prevention of Injuries for Military Recruits,” Military Medicine, Volume 168, Issue 6, June 2003, Pages 442–446, https://doi.org/10.1093/milmed/168.6.442
5) Roberta Y.W. Law, Lisa A. Harvey, Michael K. Nicholas, Lois Tonkin, Maria De Sousa, Damien G. Finniss. “Stretch Exercises Increase Tolerance to Stretch in Patients With Chronic Musculoskeletal Pain: A Randomized Controlled Trial,” Physical Therapy, Volume 89, Issue 10, 1 October 2009, Pages 1016–1026.
6) Hirata K, Yamadera R, Akagi R. “Can static stretching reduce stiffness of the Triceps Surae in older males?” Med Sci Sports Exerc. 2019 Oct 23