They recommend 2—3 days of stretching per week 2—4 repetitions of multiple stretches per day. Personal trainers sure buy into it. But not especially valuable to most athletes. Even many athletes who supposedly need extra flexibility. People love the idea of being flexible, but good luck defining specific benefits for most of them.
Read on to watch me try and fail. Flexibility is not an easy achievement to unlock. It may depend on your genes. Many other people feel defeated by the challenge as well. I have done yoga every day for more than 20 years. It is still just as uncomfortable now as it was when I started.
I can handle it for those minutes, but more is just too hard. I can still do the full version, but only for a minute or so. One would hope after so many years, doing it daily, I would become more flexible! But not even a little bit — I do the yoga for other reasons. However, for many people, a diligent effort over a period of weeks will probably increase your range of motion.
How much of an effort? When someone increases their flexibility, what exactly changes? How does it work? Turns out flexibility is much more complicated than rocket science. Do we get flexible because tissues actually get physically longer , like pulling taffy? Hint : never bet against neurology. Beliefs about flexibility and the optimal means of stretching have often proceeded from assumptions that have never been tested and from an almost religious zeal regarding the perceived benefits of stretching by a few.
Hold it right there! For how long exactly, though? And how often? How hard? What works best? Is five seconds of light stretch every other day for a couple weeks enough? Probably not. Or should it be five minutes of brutally yanking on your muscles three times a day for three months? The bottom line:. Here is a vivid example of how poorly understood this all is.
This is an excerpt from one of the text books I used in school in the late 90s, a weighty and authoritative tome, a bible of therapeutic exercise granted, out of date now, but this is the text I originally learned from :.
Several authors have suggested that a period of 20 minutes or longer is necessary for a stretch to be effective and increase range of motion when a low-intensity prolonged mechanical stretch is used.
Twenty minutes?! Almost no one is stretching for that long. Imagine trying to stretch for injury prevention: 20 minutes for each of even just 10 important muscles would be more than three hours.
In practice, most people stretch only a small selection of tissues quite briefly, seconds only, and erratically. Only the most diligent of us can actually sustain a daily habit for long.
The evidence suggests that holding a stretch for 15 seconds is better than 5… but only a little bit. In , a nicely done experiment by Marshall et al showed that regular hamstring stretching substantially increased range of motion in normal university kids. More extreme goals and methods deserve some focused attention…. Acrobats, gymnasts, yogis, contortionists, and martial artists have clearly been pushing the limits for centuries, sometimes achieving uncanny mobility.
But these are highly motivated athletes with specific and exotic performance goals and stretching regimens that would definitely intimidate the rest of us, and with good reason: they often injure themselves along the way. Indeed, it may even be necessary to injure joints — to traumatize their capsules and ligaments — in order to get them to move that far.
Even these unusual athletes are not chasing flexibility alone, and most athletes have much higher priority training goals. Fitness and health are not equivalent. Flexibility is good for a few specialized tasks … and really not much else.
It is obviously useful for gymnasts, for instance. Is this a good idea? Is this child gymnast going to be more flexible? Oh, yes, I think she will be! Will she perform better? Not necessarily: she might be better off doing strength training at the limits of her range — which will not only increase her range, but improve her control at the limits of her range. Blatantly not. And she has a middle-aged guy sitting on her back.
But, if you believe anything you read about it, overstretch sounds more dangerous than frayed-bungie-cord jumping. Ballistic stretching is a notorious old-school type of dynamic stretching that is widely believed to be useless and risky — a belief that is rich with irony.
In a world that is drowning in optimistic nutrition and fitness myths, how did this trivial idea turn into a punching bag for stretching enthusiasts? Something to scoff at? One of the only relevant studies I have ever seen actually found that a large dose of ballistic stretching actually produced much less soreness than static stretching 98 and, yes, stretching can make you sore. All of these citationless warnings are prominent in Google search results in mid They are not expert.
There is a grain of truth here, but only a grain: there is such a thing as a protective stretch reflex, but it primarily responds to rapid and unexpected stretch in the mid-range. This is covered more below in the section about how flexibility works. But no ordinary ballistic stretching intensity is hazardous enough to justify all the paranoia. In fact, if anything, I suspect that some movement at the end of the range is a cautious thing: a way of testing and exploring how the end of the range feels, of generating more raw sensory data for your nervous system to work with.
Even when they have normal range of motion in every joint. Why are people so keen on being bendier? What is it you want to do with that super power? There are several elastic superheroes. I think this speaks to our genuine craving for greater range of motion. We love that fantasy.
But the reality is that hardly anyone actually needs to be more flexible. Even abnormally poor flexibility is usually no big deal, as long as you are otherwise healthy. A couple examples:. For stretching with a flexibility goal to matter, we have to identify a common and meaningful functional limitation that can be overcome by increasing range of motion. There are lots of examples that are rare and trivial … or common and trivial … or rare and meaningful … but not both common and meaningful.
As of , Mr. This is an anecdote from someone who trained with him leading up to when he broke that record:. He was extremely inflexible. After an easy morning run 16km in 1hr10mins , I stretched with the group. Most of them were fairly flexible in the hamstrings ie. Eliud was miles off. He was nowhere near touching his toes! Matt Fox for SweatElite. When people have good aerobic capacity — when they are fit enough to efficiently distribute oxygen to all their cells — they are measurably more functional and healthier in all kinds of other ways too.
If stretching is an important part of fitness, then it too should be linked to all kinds of other good stuff. Stretching barely registers any effect on any measure of health and function. More flexible people do not die less or fall down less as they age. What actually changes when we become more flexible? Almost everyone — especially non-experts, and that includes almost all clinicians — assumes that the tissue changes.
The muscles and tendons must be different. Must this, must that. Even the stretching researchers and experts have oversimplified. There have been many ideas and many arguments. Here are some of the major specific candidates that have been explored over the years…. The idea is that stretching tinkers with these variables. Stretching may indeed change these properties, but only slightly and temporarily. Significant and lasting changes in viscoelasticity have not been observed. Every muscle is a honeycomb of fascia, and the stuff blends seamlessly into tendons at the ends of the muscle.
We call it plasticity because plastics are the best well-known example a material that can be easily, permanently changed into a new stable shape. There are many different mechanisms for plasticity. And, yes, connective tissue has some plasticity — pull on it hard enough for long enough, you can definitely permanently change it, like pulling taffy.
But doing so usually involves either injury, or extreme patience and persistence — well beyond the reach of most stretching habits.
Connective tissue is a lot tougher than taffy. This is more like pulling steel cable. Like spider silk, many superlatives apply to the properties of connective tissue. The power to deform it in a reasonable time-frame, without injury , has never been convincingly demonstrated in an experiment.
It sounds kooky, but we know that animals do in fact grow new sarcomeres when muscle is immobilized in a lengthened position. Strange as it is, this certainly seems like a plausible mechanism for increasing flexibility. The muscle also quickly loses the sarcomeres it gained. Perhaps this reflex is partly what limits range of motion, and perhaps it can be trained to be less restrictive. Sounds reasonable, no?
It primarily has a braking function: that is, it activates mainly when load is rapidly and significantly increased, something we need to do countless times per day as a part of normal activity. The biomechanical properties of muscle do not seem to change with improvements in flexibility — which seems a bit nuts, and is a bit of a brain teaser.
Brains decide when enough is enough, based on how the stretch feels. Your brain commands you to stop when it thinks the stretch is getting dangerous. And how does it enforce that? Inhibition of the muscles pulling you further into it — a kind of self-paralysis. Yes, this is my second LoTR reference in one section. Your brain is the boss of you.
The next section will dig deeper into how this actually works, and the evidence for it. In the last section, several possible ways that flexibility increases were explored and mostly dismissed, leaving only the sensory theory of flexibility. This is how Cynthia Weppler and S. Peter Magnusson explained it in their paper, framing it as the last theory standing:.
Increases in muscle extensibility observed immediately after stretching and after short-term 3—8 week stretching programs are due to an alteration of sensation only and not to an increase in muscle length.
And they do present considerable evidence supporting it. Any attempt to go further is simply shut down. Your body probably has excellent reasons for strictly limiting elongation.
We humans do not control our own brains. Hell, we can barely keep our minds on a leash. Familiarity breeds contempt. If your brain is concerned about you — and it always is, often more than you are — what better way to reassure it than to simply spend time at the edges of your range of motion, with nothing bad happening?
It appears that our brains can be tediously convinced to tolerate more elongation of soft tissue. To some degree. Just as stretching has Team Tolerance, so does athletic performance in general. We are used to thinking in terms of being held back by a variety of physical limits: we can only run so far or jump so high because the spirit is willing, but the flesh is weak. The evidence is now extremely strong that brains play a major role in regulating our effort, progressively shutting us down — for our own good — as we approach the edges of what is safe , rather than what is possible.
The brain uses all kinds of sensory cues and biological parameters — heat, thirst, pain — to keep us from exercising ourselves right off a cliff. But most experts accept that the only question is how much brains set limits.
If tolerance is a thing for several other aspects of performance, it probably is for flexibility too. It is part of a broad pattern of evidence converging on the potency of the brain in regulating almost everything. If you actually deformed your muscles and tendons enough to really preztel yourself, they might get too long and loose to be useful and functional in general. Tolerance tidily accounts for how they can both allow extreme elongation, while retaining the ability to return to a normal, functional state.
It sounds preferable. More on this below. In , Folpp et al did a nice simple experiment: they studied the effects of a month of daily minute hamstring stretches in 20 people. They measured how far the hamstrings stretched with a specific force applied, and that barely budged: one degree more movement after a month of stretching. But, adding more force, the subjects could tolerate eight degrees more stretch. So, to be clear, their hamstring muscles responded to the same force in exactly the same way despite lots of stretching.
But if more force was applied, they could go eight degrees further than when they started. In , Blazevich et al tested calf stretching: several people stretched their calf muscles twice per day for three weeks.
They were compared to people who did not stretch. Measurements included changes in muscle and tendon mechanics, muscle activity, and spinal motoneuron excitability. Increases in end ROM were underpinned by increases in maximum tolerable passive joint moment stretch tolerance. If you do some upper body stretching, your lower body will get a little more flexible.
Not much, but enough to measure in a controlled test. Increased flexibility may simply be an increased tolerance for the discomfort of excessive muscle elongation. It seems unlikely that Weppler and Magnusson had the last word in , although that paper seems well regarded. The sensory theory of flexibility has held up quite well, and it has many supporters. It is likely to be less wrong than anything else. Is not! The study of flexibility I cited above is good example of stubbornly defending plasticity in a more scholarly style.
I see a lot of this kind of thing from Team Plasticity these days: weak arguments that seem to miss the point. But they are not completely without evidence to support their position. This is the best example I am aware of, and the only one that I consider to be a solid point against Team Tolerance:. It just remains the best non-eliminated explanation. But of course it is possible that flexibility can increase in more than one way.
How about this? It may have a lot to do with why massage feels good. But stretching is probably not good for the reasons most people are stretching — not much good, anyway, and certainly not much in any ways anyone has figured out how to measure.
Undoubtedly, some specific stretching techniques are good for specific purposes … but quite different from the stretching goals that most people actually have in mind, if they have any clear goals at all.
My concern is not that stretching itself is useless, but that people are stretching aimlessly and ineffectively, to the exclusion of evidence-based alternatives, such as a proper warm-up or mobilizations. But for most people, most of the time?
As a time-consuming therapeutic exercise ritual? Stretching simply has a lousy effort-to-reward ratio. In the next few sections, I will respond to some of the common objections and questions that readers often have. Unfortunately, none of them can agree with each other. Yes , it is, and yes , it does — but probably not the benefits that people normally attribute to stretching.
Even flexibility is suspect. I advocate this kind of stretching elsewhere in my writings. The difference is in intention. The intention of stretching in the context of good qigong, yoga or martial arts is to focus the mind, to stimulate vitality through a combination of mental and physical exercise.
The intention is everything — without the intention, you might as well not bother with these activities. Most westerners stretch without the foggiest notion of this underlying complexity. And stretching in yoga also involves some risks. Too often people perceive yoga as an entirely wholesome and harmless activity, but in fact over-stretching injuries and muscle strains are actually common. As with dancing or martial arts, there are many ways to hurt yourself practicing yoga. We already know that stretching does not do all the basic stuff we used to hope it was doing, especially injury prevention.
Is it good for anything else? Did you find this article useful? I am a science writer in Vancouver, Canada. Full bio. See you on Facebook or Twitter , or subscribe:. More info. This article had a long history of unlogged updates — a decade or so — before I finally started logging them in Updates shown here are the most recent only. May 3, — New section: No notes.
Just a new chapter. May 3, — Rebooted: Over the last couple weeks, this article has been upgraded and expanded in many ways.
It is now about 33, words long, which gives it the dubious distinction of being the first PainSci article to match the length of the shortest PainSci book. So…the change must exist in another system. This theory was built around the idea that stretching could retrain the nerve receptors in muscle and ultimately change how they function reflexively. Changing reflexes seems unlikely — but stay with me for a moment. This feedback is then used to protect the muscle by engaging more fibers to increase the contraction or by shutting the muscle off to prevent rupture.
That was the theory at least. This was why ballistic or bounce stretching has been discouraged for years!
Drum roll please… Well, the experimental evidence did not support a neuromuscular reflex change as the cause of any of these assertions. Stretch reflexes have been shown to activate primarily during very rapid and short stretches of muscles that are in a mid-range position not an end-range position like a stretch. They also only produce a muscle contraction of very short duration — not a long, resting muscle hold.
This theory proposes that increases in muscle extensibility are due to a modification of sensation only. Basically, what you feel while stretching changes, so you are able to stretch further. No mechanical change, no re-programming of your reflexes! Even better — the current studies support that increases in muscle extensibility observed after a single stretching session and after short-term 3- to 8-week stretching programs are due to modified sensation.
The simple description is that when you stretch, you experience the sensation of stretching. During that time the body begins to perceive less and less of the stretch aka desensitization as the sensation your muscle is providing is not new or useful information. Initially you notice them on your feet, but then after a few minutes, you no longer feel the socks. Ok, so now what? What motions are you targeting?
Think of stretching as functional. Does it matter which muscle is the most limiting? Where is your baseline? Take a photo so that you can set reasonable goals. Be honest with yourself so you stick to your routine! Pushing past this will likely work against you, since too much pain will cause a guarding response from the muscles that is counterproductive. Have answers to those questions?
Give it a numerical rating mild range please and stay constant. Not so fast. Studies about the benefits of stretching have had mixed results.
Some research shows that stretching doesn't reduce muscle soreness after exercise, and other studies show that lengthening the muscle and holding the stretch immediately before a sprint may slightly worsen performance. However, research has shown that stretching can help improve flexibility, and, consequently, the range of motion of your joints. Stretching also increases blood flow to the muscle. You may learn to enjoy the ritual of stretching before or after hitting the trail, ballet floor or soccer field.
Before you plunge into stretching, make sure you do it safely and effectively. While you can stretch anytime, anywhere, proper technique is key. Stretching incorrectly can actually do more harm than good.
Don't consider stretching a warmup. You may hurt yourself if you stretch cold muscles. Before stretching, warm up with light walking, jogging or biking at low intensity for five to 10 minutes. Even better, stretch after your workout when your muscles are warm.
Consider skipping stretching before an intense activity, such as sprinting or track and field activities. Some research suggests that pre-event stretching may actually decrease performance. Research has also shown that stretching immediately before an event weakens hamstring strength.
Also, try performing a "dynamic warmup. Focus on major muscle groups. Concentrate your stretches on major muscle groups such as your calves, thighs, hips, lower back, neck and shoulders.
Make sure that you stretch both sides. Keep up with your stretching. Stretching can be time-consuming. But you can achieve the most benefits by stretching regularly, at least two to three times a week. Skipping regular stretching means you risk losing the potential benefits.
For instance, if stretching helped you increase your range of motion, your range of motion may decrease again if you stop stretching. Bring movement into your stretching. Gentle movements, such as those in tai chi or yoga, can help you be more flexible in specific movements. These types of exercises can also help reduce falls in older adults.
Remember the "dynamic warmup": If you're going to perform a specific activity, such as a kick in martial arts or kicking a soccer ball, start out slowly and at low intensity to get your muscles used to it. Then speed up gradually.
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