Stretching is an essential part of our life. It can be intentional stretching when the muscles are pulled on to elongate them. Or it can be an automatic and unconscious stretching, like when we wake up or stand up after prolonged sitting. Runners stretch before hitting the distance, ballet dancers stretch before relever or plie, yogis stretch because every asana demands some level of flexibility, and office workers stretch to relax the tension in their muscles.

You stretch to acquire flexibility and improve your range of motion. We tend to believe that stretching eliminates the possibility of injury. We stretch to decrease muscle soreness or to prevent it after exhausting exercises. We think only about the benefits of stretching. What we don’t know, or tend to disregard, are the side effects of stretching.

We overrate its advantages and bestow stretching with significant benefits.

In this article we’ll focus on one kind of stretching,- Static Stretching (SS) during which you hold your muscles without movement for a certain amount of time – usually from 30 to 60 seconds – until you feel the relief of tension. We do SS to become more flexible, to prevent injury, to relieve pain, decrease soreness in muscles, and to warm up our bodies.

But can SS really help? If Yes, at what cost?

How Stretching Works! A little bit of anatomy…

Have you heard of the Stretch Reflex? According to Merriam Webster Dictionary, Stretch Reflex is

“A spinal reflex involving reflex contraction of a muscle in response to stretching [1].”

• In other words, stretch reflex is a neural response to the change in muscle length.
• Once your nervous system notices your muscle is being stretched, it automatically contracts the muscle to protect it from overstretching and subsequent injury [2].
• Stretch reflex is an essential part of a system that protects muscles from injury. When the muscle receptors sense a change in muscle length, they send a signal to the spinal cord and muscles are contracted to avoid injury and prevent your muscles from extreme elongation.
• When resisting, your nerves are screaming to stop stretching beyond your normal range of motion. It’s like a battle between your conscious mind to go further and your body’s automatic response to resist stretching.

What happens when you stretch longer than 30 seconds:

• Your stretch reflex becomes weaker and leaves muscles lengthened for some time. When muscles become stretched, it makes it difficult for them to contract. The weakening of muscles can decrease physical performance.

“The straining muscle becomes less responsive and stays weakened for up to 30 minutes after stretching, which is not how an athlete wants to begin a workout.[3]”

• Your muscles stay elongated only for a short period of time: this is the time you feel flexible with an enhanced range of motion.  
• But! After some time, the stretch reflex will kick in, the effect of loose muscles will disappear, and the tension in muscles will return.

• A Sense of Tolerance: Stretching will make you flexible by increasing tolerance to the feeling of pulling on muscles. When performed on a daily basis, the slight pain from stretching becomes tolerable and you even get satisfaction from it. This is a habit. Our nervous system learns and becomes accustomed to our daily movements. Your muscles can become unhealthy with micro injuries from overuse and overstretch of muscle fibers. Also, keep in mind that if you stretch longer than 30 seconds, you begin to stretch your ligaments!

 

Let’s debunk some popular myths about Static Stretching!

To begin with, SS is a controversial topic to discuss and scientists still don’t have a clear answer to the potential benefits and threats of SS. However, the research clearly shows that:

1. Stretching is NOT Good for Warm Up

Three Studies Show that Stretching Decreases Muscle Strength

Research conducted by scientists, the University of Northampton, showed that stretching for 30-45 seconds produced no significant effect on muscle productivity during exercises [4]. In addition, they showed that SS can reduce muscle strength and physical performance.

• Another study from the University of Nevada demonstrated that static stretching reduced athletes’ performance: muscle strength appeared to be 30% less in runners after SS [5].
• Research conducted by scientists at the Motor Control and Human Performance Laboratory proved that pre-exercise SS significantly inhibits muscle performance: 104 studies on stretching were analyzed with different age, sex, or athletic level, and the result showed that SS before a workout impaired strength performance [6].

Consequently, stretching muscles before an intense workout make them weaker; thus reducing physical performance. Muscles become more tense.

2. SS doesn’t Reduce Delayed Onset Muscle Syndrome

During a workout, the muscle lengthens and contracts under tension and tissues are damaged, resulting in micro tears. These micro tears can heal within 48 hours, but if you continue pulling on muscles, the injury will become more severe. The nagging pain you have after the workout is called Delayed Onset Muscle Syndrome, or DOMS. It is commonly believed that SS can reduce DOMS; however, the research shows the opposite.

• According to the research published in Scandinavian Medical Journal, SS doesn’t prevent Delayed Onset Muscle Syndrome. 7 untrained women, aged 28-46, performed eccentric exercises until exhaustion. Despite static stretching before exercising, all participants had pain in their quadriceps which intensified up to 48 hours after the exercise [7].

• A study conducted by the George Institute for Global Health reports that a review of 12 studies clearly shows that muscle stretching, regardless if conducted before or after practice, doesn’t produce a significant reduction in DOMS [8].

3. SS Doesn’t Reduce Injury

There is a popular myth that “longer” muscles are less likely to get strained. By stretching before physical activity, the idea goes, you increase your range of motion, become more flexible, and are less likely to be injured. However, studies don’t confirm this popular opinion.

• A study conducted by CAQ Sports Medicine showed that the risk of injury in runners over a three-month period with pre-stretching activity was the same as for those who didn’t stretch. Stretching didn’t prevent injury to the 1,200 subjects who stretched and who didn’t [9].
• Another study conducted by the Amager Hospital Department of Orthopaedic Surgery in Copenhagen showed that injuries cannot be prevented by static stretching. 1,020 soldiers engaged in an exhausting exercise program, with one group doing 5 stretching exercises before the performance and the other doing nothing [10]. At the end of the program, there were 223 injuries, with 50 of them in the group which performed stretching and 48 who did nothing.

4. Static Stretching Can Cause Injury and Lead to Stiffness!

• Hypermobility of joints
• Back and neck injury
• Muscle strain and sprain

SS can lead to hypermobility – excessively mobile and unstable joints. When you push over your body’s normal range of motion, your muscles are not stretching, but, rather, it is your ligaments getting into the process. Ligaments attach bones to bones, and when they are overstretched the bones become hypermobile and lack stability.

Loose muscles and ligaments cause more friction between bones and can lead to wear and tear of the joints. Once ligaments go lax, they never go back to their original length [11]! Stiffness can increase because ligaments become extremely loose and fail to work efficiently. Muscles are forced to take on the responsibility, carry more weight, and become overstrained.

In addition, overstraining muscles causes micro-injuries, which can lead to muscle and ligaments tears.  Small tears in the connective tissues can lead to flexibility combined with extreme stiffness. This is a common problem for yoga practitioners.

5. SS Doesn’t Relieve Muscle Pain and Stiffness…

“If you want to untie a knot, you must look at the cord carefully then gently undo the tangle. Yanking on the cord will only make the knot tighter [12]”.  Thomas Hanna

Stiffness is a sensation and is a particular state of soft tissues; it is not the same as being inflexible or having a limited range of motion. This unpleasant feeling is a reaction to:

• Infections;
• Inflammation, like from the inflammatory joint disease Rheumatoid Arthritis;
• Muscle overstrain or, on the contrary, lack of activity;
• Stress;
• Sleep problems;
• Poor nutrition, lack of vitamins and minerals;
• Unhealthy connective tissues, such as Myofascial Pain with Trigger Points, a chronic condition that affects the fascia (connective tissue that covers the muscles).

Imbalanced Posture is a major culprit of muscle pain. If you are sitting in a slouched position with your head shifted forward in front of the computer for 8 hours a day,

this position becomes a natural habit for the body. When you move, your shoulders stay slouched, and your head moves forward.

This increases tension in your neck muscles, which support your head. Muscle tightness running through the neck to the upper back leads to painful spots in your tissues – muscles knots.

Having improper posture means that some of your muscles are over lengthened and weakened, while others are kept tense to keep your balance. Consequently, when you stretch muscles that are tight to make you stable, you’re causing more problems for your body.

Imbalanced posture can also cause pain in your legs, caused by the lack of stability in the core. This is very common for people who have tight hamstrings. SS isn’t a Solution! Muscles are kept tensed and short by the brain and sensory-motor system. If elongation is the desired result, then SS cannot help because the effect of pulling on muscles doesn’t reach the brain.

 

Summing up…

Despite the fact that Stretching is an essential part of our life, we shouldn’t overrate its benefits! We all have an innate desire to stretch, to extend our bodies, to feel the pleasure of being more flexible. But the cost of more flexibility and increased range of motion will be paid by your connective tissues, which will become unhealthily flexible and tense.

Finally, SS isn’t the best way to warm up your body before exercising, to prevent Delayed Onset Muscle Syndrome – DOMS or to prevent injury. It doesn’t relieve pain and release tension but can, on the contrary, cause more pain and more stiffness.

 

References:

[1] Merriam Webster Dictionary. Stretch Reflex.

[2] Michael D. Mann, “Muscle Receptors,” in The Nervous System in Action, University of Nebraska Medical Center (UNMC). 15th March 2009. 

[3]  McHugh Malachy, “Stretching: the Truth,” New York Times.

[4] Kay AD, Blazevich AJ. “Effect of Acute Static Stretch on Maximal Muscle Performance: A Systematic Review.” Med Sci Sports Exerc. 2011 Jun 8. PubMed #21659901

[5] Mojock CD, Kim JS, Eccles DV, Pantlon LB. “The Effects of Static Stretching on Running Economy and Endurance Performance in Female Distance Runners During Treadmill Running”. Journal of Strength and Conditioning Research 2011; 25(8): 2170-2176.

[6]  Simic L, Sarabon N, Markovic G. “Does pre-exercise static stretching inhibit maximal muscular performance? A meta-analytical review.” Scand J Med Sci Sports. 2013 Mar;23(2):131-48. doi: 10.1111/j.1600-0838.2012.01444.x. Epub 2012 Feb.

[7] Lund H, et al. “The effect of passive stretching on delayed onset muscle soreness, and other detrimental effects following eccentric exercise.” Scand J Med Sci Sports. 1998 Aug;8(4):216–21.

[8] Herbert RD, de Noronha M, Kamper SJ. “Stretching to prevent or reduce muscle soreness after exercise.” Cochrane Database Syst Rev. 2011;(7).

[9] Shrier I. Stretching before exercise does not reduce the risk of local muscle injury: a critical review of the clinical and basic science literature. Clin J Sports Med. 1999 Oct;9(4):221-7.

[10] Brushøj C, Larsen K, Albrecht-Beste E, et al. “Prevention of overuse injuries by a concurrent exercise program in subjects exposed to an increase in training load: a randomized controlled trial of 1020 army recruits.” Am J Sports Med. (April 2008), 36(4): pp. 663–670.

[11]  Birney, Bernadette. “Joint Hypermobility Syndrome: Yoga’s Enigmatic Epidemic?.” Yoga International.

[12] “Pandiculation – The Safe Alternative To Stretching,” Essential Somatics.