Once again I find myself dumbfounded by another misleading article on flexibility and it’s so-called “dubious” benefits. The title of the article is “Why Stretching Doesn’t Make You More Flexible”, which is an obvious “shock” statement meant to get your attention because it contradicts conventional thought. I read the article on a popular news website The Huffington Post, but the article was originally written for LiveScience.com and then reposted on Huffington.
The article is targeted toward a general audience, but simplifying the science doesn’t include changing the premise and using selective information that is incomplete or doesn’t substantiate a coherent argument. The author begins the article saying that certain people (athletes, yogis, etc.) stretch to help their performance. But then she postulates, “But does stretching really prevent tight hamstrings and stiff shoulders?”. This changes the premise to “prevention”, as opposed to that of “increasing flexibility”. These are two different purposes and the “prevention” idea is never addressed. And one amazing thing about this article is that all of the experts she quotes and refers to say that stretching does increase flexibility, so the title is contradicted throughout.
In the article, she quotes two different yoga instructors and one scientist. Although the author tries to confuse the issue by claiming scientists don’t know how or why stretching improves flexibility, the explanations presented by the experts are actually pretty clear on how the body adapts to stretching to make you more flexible. Basically, as anyone who has tried stretching can attest, when you first begin a stretch it hurts, but the more you practice it, the less it hurts and you can lengthen the muscle more. One of the biggest mistakes made by the author is that she equates the action of “lengthening a muscle”, which is what you do when you stretch it, with the actual “length of muscle tissue”. She correctly states that, “Muscle tissue attaches at fixed points in the bone, so the entire muscle complex can’t get permanently longer.” But the length of a muscle is NOT a measure of your flexibility. Flexibility is a measure of the ease with which a muscle can move from a contracted state (shortened) to a fully extended state (lengthened). The study results referred to in the article are measuring only data on the length of the muscle, not it’s elasticity or flexibility.
Because she doesn’t let go of the premise that flexibility and length of a muscle are one and the same, she then states, “So, if muscle fiber doesn’t get longer as a result of stretching, why does stretching seem to increase people’s flexibility?” I italicized the word “seem” because it implies that the increase in flexibility is not real. This is so disingenuous, and goes back to the whole misleading title selected for the article in the first place. The fact is the nervous system is part of the body and muscles have nerves and changes in pain reflexes is not in our minds, but actually part of the very real adaptation process of training, and fortunately, this is adequately explained later in the article.
In the last few paragraphs of the article, the author tries to give some guidance on the best way to stretch – PNF vs static stretching, briefly referring to one study showing PNF helped gymnasts. However, she completely fails to properly describe what PNF is, saying it involves tightening (contracting) the muscle at the same time as you try to lengthen it. That is not how PNF works, which involves a short period of contraction (2-3 seconds) of the restricted muscle, and then relaxing that muscle and contracting the opposing muscle. This is repeated several times for noticeable improvement in ROM. For a more thorough description of PNF see this Wikipedia link. I believe as this author is working for an educational/information website, it is important to note the serious misinformation in this article. Lastly, the author incorrectly states that loading a muscle with more force at a greater level of extension “tells the nervous system that the muscle can be strong and safe at that level of extension”. While she claims this information was told to her by the yoga instructor, I believe she misunderstood her. More force at greater levels of extension will cause the nerves to tell the muscles to reflexively tighten even more to protect them from over stretching or pulling. The greater the range of extension in a joint, the more reflexively will the nerves tell the body to tighten up to protect itself. PNF, like all good stretching techniques, needs to be done gradually and patiently, without using too much force or pushing to the end ranges of motion.
I do hope I have helped stem the flow of bad information about stretching and please keep stretching regularly. Your body will thank you!!!
There are more articles on stretching in my blog. Please check it out and comment if you want.