Athletes stretch mostly to warm-up, prevent and treat injuries, and to boost performance mainly through flexibility. Only one of those popular reasons for stretching has ever held up to scientific scrutiny, and even that one is only half true: stretching will indeed make most people more flexible, if you work hard enough at it, but flexibility is mostly worthless to the average athlete, and even most elite ones.
Stretching has a place of honour in athletics, sports medicine, and fitness — it is an activity everyone loves to love — and yet it is arguably the most over-rated thing you can do with a body.
For a bird’s eye view of stretching, see Quite a Stretch. For information about stretching as a form of self-treatment for pain, see Stretching for Pain (and Pleasure). For more about the science of stretching and flexibility, see Stretching for Flexibility.
But for the science of stretching in sports and fitness… just keep scrolling.
What a sensible article, and about time somebody exploded the stretching myth! I remember as a schoolboy in South Africa forty years ago always being told to run slowly to warm up for our various rugby, cricket, and soccer games — nobody ever told us to stretch, and over the past ten or so years I’ve been puzzled to see this come in as dogma. As a runner of marathons for years and a GP with injured patients, I’ve never been able to figure out how on earth stretching the heck out of muscles, ligaments, and nerves could (a) warm them up or (b) do the slightest bit of good, and have sometimes been given “the jaundiced eye” when I’ve suggested such to my patients.
~ Peter Houghton, MD, Vancouver (reader feedback)
When challenged, stretching enthusiasts — both casual and hardcore — have surprisingly hard time explaining why they are stretching. Everyone just “knows” that it’s a good thing, and they haven’t really thought about why. It’s dogma, practically a religion.
When pressed for reasons, most people will cough up a few predictable stretching goals. Here are the four hopeful reasons for stretching that I hear every day:1
- flexibility, of course
- warm up and injury prevention
- prevention/treatment of exercise soreness
- treatment of sports injuries and chronic pain
And a fifth which I only hear occasionally, but it’s still out there:
- “performance enhancement” (e.g. faster sprinting)
All of these overlapping goals for stretching have serious problems. Either they have long ago been proven to be impossible,2 or they never made sense to begin with, or both, or worse. Certainly none of them is a slam dunk. They will all be critically analyzed below.
Bonus reason to stretch!
It feels good, obviously. This is the neglected bonus reason for stretching I can get behind.
You cannot “warm up” your muscles by stretching them: it’s like trying to cook a steak by pulling on it. Instead, the best way to warm up is probably to start by doing a kinder, gentler version of the activity you have in mind (i.e. walk before you run). The metabolic activity involved in muscle contraction does literally warm up your muscles, an inevitable side effect of all the activity that actually makes warm up effective for injury prevention.
Nothing about static stretching is more clear than this failure. Your basic quick (static) stretch warmup is one of the most studied topics in all of musculoskeletal health care and exercise science. For instance, a huge 2011 review of all the research found “overwhelming evidence that stretch durations of 30-45 seconds … imparted no significant effect” and even some evidence of harm.5
Um, harm? Slight harm, yes: a 2014 test found that a nice pre-run stretch causes “a reduced capacity of the skeletal muscle to produce explosive force.” Yikes. As Alex Hutchinson put it for Runner’s World, “I can’t see anything good about something that makes me go slower but feel like I’m trying harder.”6 And there’s more like that.7
Metaphorically, “warming up” also refers to readiness for activity or body awareness. You are “warm” in this sense when you are neurologically responsive and coordinated: when your reflexes are sensitive and some adrenalin is pumping. Warmup for its own sake (i.e., without following it up with more intense exercise) is fairly pointless — the goal is to prevent injury and enhance performance. And those goals may be realistic. For instance, research has shown that a warmup routine focused on these goals actually does provide decent insurance against the number and severity of both accidents and over-use injuries.89
So, warmups in this second sense is probably helpful … but does stretching warm you up in this sense? No, probably not much — certainly no more than a bunch of other exercises you could do — and quite possibly not at all. One of the most-studied warmup regimens (including one of the studies just cited), FIFA’s “The 11+” programme, notably does not include stretching. The most compelling evidence that stretching doesn’t warm you up is the evidence that shows that it doesn’t prevent injury or enhance performance (discussed below). Static stretch is somewhat stimulating to tissue, but in ways that are quite different from most actual activities.
A large study of girls’ soccer teams showed warming up can cut injury rates by about a third. Notably, the warmup that was studied, FIFA’s “11+” warmup, did not include stretching!
Because of all this, stretching to warm up does not even qualify as “official” exercise dogma anymore — most professionals actually gave up on it many years ago, and it is passé even in the opinion of a great many more informed joggers and weekend warriors. It simply doesn’t work, and it’s hard to imagine a common fitness practice more thoroughly contradicted by the evidence and by many professionals. And yet …
And yet I still see it all the time in the wild. I live and play on Vancouver’s famous “sea wall” — one of the best and most popular running routes in the world. I am able to constantly observe runners in their natural habitat, doing what runners do, and a great many of them participating in structured training programs and running groups, clearly being instructed by experts and coaches.
And they stretch to warm up. In droves. So despite the evolution of professional opinion, this practice clearly still needs to be debunked. There are still far too many people out there stretching before they run and play sports, trying to “warm up” almost exclusively by standing still and elongating muscles!
Once again, the best way to prepare for an activity is probably just to start it slowly.
Another extremely popular idea about stretching is that it prevents a specific type of soreness: the deep soreness that follows a hard workout. That phenomenon is called “delayed-onset muscle soreness” (DOMS) or sometimes just “post-exercise soreness.” Many people believe that stretching can help DOMS. Some seem to believe it like it’s their religion, and it’s amazing how determined people can be to ignore evidence that contradicts it.10
Recently (2016), decades after this faith first got entrenched, science finally coughed up a specific reason why it might be based on something: evidence that stretching reduces inflammation in connective tissue.11 (Exercise in general is anti-inflammatory,12 and maybe this is partly why.) Surely this is relevant! It sure sounds like great science factoid to explain why people think stretching helps soreness after exercise. Practically a slam dunk! It is interesting evidence for sure, and I’ll return to it later.
But there are many problems with leaping to that conclusion.13 It’s a classic mistake to assume that a scrap of biological relevance translates into a clear benefit in the real world. Unfortunately, the evidence strongly suggests that stretching does not prevent DOMS. Many studies have shown that nothing short of amputation can prevent DOMS141516 — and certainly not stretching.17 Whatever effect stretching has on inflammation in connective tissue, it does not add up to a DOMS cure.
The commonly accepted idea that increased ROM and stretching prior to activity prevents injuries has been challenged and found to be on the shakiest of scientific foundations, or to come from such a paucity of data that no reasonable conclusions can be drawn.
~ Flexibility, by William Sands, p. 389
According to the evidence, stretching probably does not prevent injury. As I mentioned above, this has been suggested by a combination of recent literature reviews and large clinical studies, some of which I have already cited. Here’s some more.
In 2005, the Clinical Journal of Sports Medicine published a review of the scientific evidence to date, and found that the (admittedly limited) evidence “showed stretching had no effect in reducing injuries.”18 Neither poor quality nor higher quality studies reported any injury prevention effect. Regardless of whether stretching was of individual muscles or entire groups, there was no reduction in injury rates.
More experimental research has been done since. For instance, a 2008 study published in the American Journal of Sports Medicine showed “no significant differences in incidence of injury” in soldiers doing preventative exercises.19 Half of them participated in an exercise program including 5 exercises for strength, flexibility, and coordination of the lower limbs, and 50 of those soldiers sustained overuse injuries in the lower leg, either knee pain or shin splints. The other 500 soldiers were doing nothing at all to prevent injury in the lower limbs — no specific stretching, strengthening or coordination exercises — and only 48 of them had similar injuries. There were “no significant differences in incidence of injury between the prevention group and the placebo group,” and the authors concluded that the exercises “did not influence the risk of developing overuse knee injuries or medial tibial stress syndrome in subjects undergoing an increase in physical activity.”
However, what is clear is that the exercise regimen certainly included static stretching, and it certainly did not work any prevention miracles for some of the most common athletic injuries from the knees down. If stretching performs that poorly in such an experiment, how good can it possibly be at preventing other injuries? Probably not very.
Here in Vancouver — a running Mecca — researchers at Simon Fraser University have done an unusually large study of pre-run stretching, with more than 2700 participants. They found “no statistically significant difference in injury risk between the pre-run stretching and non-stretching groups.”20 Injury rates for all kinds of injuries were the same, with or without stretching. It’s almost as though stretching made no difference at all. But make up your own mind!
I’m never surprised by such findings, because I’ve never heard a sensible explanation for how stretching can generally prevent injury. Usually, advocates have a vague notion that “longer” muscles are less likely to get strained: even if garden-variety stretching made muscles longer (which is doubtful in itself), and even if we knew exactly what kind of stretching to do (we don’t), and even if we had the time to stretch every significant muscle group, the benefits would still be relevant to only a small fraction of common sports injuries. An ankle sprain, for instance, or a blown knee — two of the most common of all injuries — probably have nothing to do with muscle length.
Not convinced yet? A 2014 review of exercise therapy for injury prevention in the British Journal of Sports Medicine was completely negative about stretching21 — even though the authors were obviously a bit too optimistic about everything else!22 “Consistently favourable estimates were obtained for all injury prevention measures except for stretching.” Ouch.
There may be some injury prevention powers to stretching — muscle strains seem like the most likely candidate23 — but probably quite specific and missed by many basic, general pre-event stretching regimens.24 For injury prevention, I can think of Sports Injury Prevention Tips that are probably more effective/efficient than stretching.
That which prevents injury often treats it as well, and vice versa, and that’s the basic rationale for stretching as a treatment for injury. People believe that stretching prevents injury, so they believe that it can treat it as well — in a better-late-than-never way. Unfortunately, we already know that stretching doesn’t prevent injury, so it’s unlikely that it can treat it either.
But there are some more elaborate rationalizations for stretching as a treatment, chiefly that it corrects something.
Exercise is the closest thing there is to a general miracle drug,2526 and strength training is one of the best types of exercise, practically like magic: healthier and more efficient than most people realize.27 It’s also widely accepted as a major part of injury rehab, and stretching goes along for that ride. Although it’s not taken anywhere near as seriously as strengthening, millions of athletes, trainers, coaches, and healthcare professionals still consider it to be a staple of rehab.
Tedious and specific “corrective” or “therapeutic” exercises are a tired cliché of rehab and physical therapy, both strengthening and stretching. It’s what everyone (athletes and non-athletes alike) imagines their training montage will look like if they are ever hurt.
Unfortunately, corrective exercise isn’t a great reason to build strength, and its an even poorer justification for stretching. This style of rehab is largely based on the flawed and even harmful assumption that there is something in-correct about injured patients — fragile, weak, uneven — which must be fixed by sufficiently expert and precise exercise prescription.
For instance, there is often an alleged “imbalance” that consists of both overstretched and weak muscles that need to be toughened and tightened up, and tight and overworked muscles that need to be loosened and stretched.28 It’s surprising how much that single idea has boosted the perceived importance of stretching in the rehab equation.
Stretching obviously doesn’t have much to contribute to load management. At best, it could be considered a form of light exercise that could be used for some stimulation in the early stages… but you could and probably should mostly just stick to dynamic joint mobility drills and very easy strength training instead.
If there’s any other justification for stretching in rehab, it has to live in the much smaller neighbourhood of rehab that isn’t all about load management.
Protecting or restoring range of motion after injury
This is the most reasonable reason to stretch for rehab: not because it helps the injury itself to heal, but to prevent any related loss of range of motion, or to restore it. As explained in detail in a separate article, there is no doubt that stretching can improve range of motion. But more ROM does not have clear value in general. Many factors restrict its importance even further in a rehab context.
Stiffness is the sensation that inspires stretching in rehab, but injury stiffness — the stiffness that typically afflicts the joints near an injury — usually has nothing to do with “tight” muscles and tendons. It’s mainly just a neurologically imposed inhibition of movement, a kind of pain, a warning about movement rather than a lack of it. To the extent that it actually does involve any shortening of muscle, it’s probably either minor and temporary and things will get back to normal on their own… or it’s more serious and cannot actually be affected by stretching in any case.30
I think there are some clinical scenarios where a little stretching to maintain or restore post-traumatic ROM is probably worthwhile, but they are minor and rare.
Specific stretching for specific injuries
If not to maintain and restore range of motion, why else would you stretch an injury? What else could stretching do for an injury? Most people imagine that it’s about restoring balance: fixing things that are “too tight” and holding back recovery in some way, probably by constantly irritating the injury. In many cases, this hypothetical restriction is considered the root cause of the injury in the first place, which must be addressed to allow healing to proceed.
Stretching itself is not generally rehabilitative, because a limited range of motion does not usually cause or sustain injuries. Every kind of injury has to be considered separately, because there are all kinds of specific ideas about why one should stretch to fix different injuries. But if you go through a list of injuries and their presumed mechanisms, not many of them cannot clearly be blamed on anything that stretching can fix. Maybe none.
For instance, people believe that the reason they get iliotibial band syndrome, one of the two common kinds of runner’s knee is because the iliotibial band is “too tight.” Unfortunately, that almost certainly isn’t the problem, and the IT band is much too tough a structure to stretch in any case.31
A calf-stretching gadget, one of many on the market that are sold with claims that they can treat plantar fasciitis. Science isn’t so sure.
But the arguments for and against stretching for ITBS are completely different than they are for, say, muscle strains or low back pain. Different kinds of injuries, different arguments about stretching. My plantar fasciitis book goes on for three chapters about the possible role of stretching in treating that condition, but the bottom line is that it either doesn’t work, or not all that well.32
Over time, I will expand on a few other major examples. For now, suffice it to say that
There are a handful that might be in the “promising” category, where it’s probably worth giving it a try. It’s not like stretching is expensive or risky. But even in those cases, it’s always arguable that dynamic joint mobility drills and strengthening would be better choices. For instance, in the case of muscle strain (tear), stretching may help cue the healing mechanisms in your muscle to lay down new connective tissue in a tidy way, and there’s even evidence to support that33 … but so will gentle contractions. Simply using the muscle almost certainly does the same thing, or does it better.
You can go back and forth like this with almost any injury, but the bottom line is that stretching has never been found to make a significant difference in anyone’s rehab.
Ironically, stretching can actually cause some of the injuries it is thought to prevent or treat. Although stretching is mostly a safe activity, especially if practiced with a modicum of caution, there are (at least) four potential types of stretching hazards:
- Stretching as a warmup may modestly impair athletic performance, as discussed above. Not a huge concern, but not exactly what people want from their stretching either.
- Traumatic injury (sprains and strains) from over-stretching, fairly common in yoga, dance, martial arts, and so on. People just overdo it.
- Traumatic injury to people who should never stretch (but may not know it) because of medical vulnerabilities directly related to flexibility, mainly the hypermobility spectrum disorders and connective tissue diseases (e.g. Ehlers–Danlos syndrome, Marfan syndrome).
- Unexplained body pain may be worsened by attempts to stretch, for a variety of reasons, probably mostly related to aggravating pre-existing conditions.
Hypermobility and Ehlers-Danlos syndrome
Some people are much more flexible than average — pathologically flexible. “Hypermobility spectrum disorders” (HSD) are a group of conditions defined by joint hypermobility — unexplained joint looseness.34 Ehlers–Danlos syndrome (EDS) is a closely related group with known genetic causes35 that includes hypermobility along with fragile tissues that heal poorly, especially skin, with many consequences. All of these conditions together are quite common, and chronic pain is a routine complication.36
Most people don’t need to stretch, but people with HSD/EDS really should not stretch … and they may not know it. HSD/EDS is often undiagnosed and mistreated; it is clinically important and yet often non-obvious. So lots of people are probably suffering without having any idea why or that they shouldn’t be stretching. Consider this story from a 75-year-old reader:
Upon continued strong urging by my physical therapist, I engaged in “glute” and “quad” stretches — quickly to my detriment and horror. MRI survey confirmed gluteal minimus and medius tendinitis and partial thickness tendon tears.After a year of seeking help and ineffective treatment I was just this month diagnosed by a rheumatologist with hypermobility joint syndrome.
This condition does not seem to be on the “radar” of most docs or PT’s. As a kid, I delighted in acrobatics, some said I was “double-jointed”; and in high school and college, modern dance (which included acrobatics). I was still dancing and hiking up until a year ago, but this injury has been devastating!
Now I understand the problem, so my rehab routine is strengthening within a normal range of motion. Feel-good, easy whole-body stretching only. Swimming has been a great help, along with careful exercising with weights at the gym.
It’s awful that this patient, with a long history of hypermobility, was convinced to overstretch by “strong urging” from a healthcare professional. This is a perfect example of clinical ignorance of hypermobility and the consequences of unjustified enthusiasm for stretching. Most people, even healthcare professionals, are simply oblivious to how common and serious hypermobility is — but it’s highly relevant to the value and safety of stretching.
Hypermobility is a common vulnerability that is directly related to stretching. There are many other medical conditions that have nothing obvious to do with stretching, but can be aggravated by stretching. A simple example: back pain has many possible causes, several of which might be aggravated by stretching, even severely.
And yet people routinely attempt to self-treat back pain with stretching, more or less oblivious to the possibility that it will do more harm than good in some cases.
Here’s the story of my own ill-fated attempt to treat some neck pain with stretching:
The most flexible athletes are not necessarily the most successful.
~ Flexibility, by William Sands, p. 389
You don’t hear this argument for stretching as often as your hear the others. And yet it comes up, especially with runners, and with athletes who play sprinty team sports. It’s a common practice to stretch when you’re off the field. The habit is probably usually rationalized as an injury prevention method, but many of those athletes will also insist that it enhances their performance — that the muscles “spring back” from the stretch and make them run faster.37
I’ve already mentioned a huge 2011 scientific review by Kay et al that found “overwhelming evidence” that pre-exercise stretching has “no significant effect.” That was not a surprise. What is a little surprising is that the same review showed the opposite of a benefit — that pre-exercise stretching might reduce muscle strength.38 I wouldn’t take the danger too seriously, but it certainly emphasizes the lack of benefit: if anything, it swings the other way. Yikes!
Similarly, research has shown that stretching does not improve sprinting … but it gets worse. What really happens to your sprint if you stretch first? It turns out that, all other things being equal, the athlete who didn’t stretch is actually going to leave you behind! An Australian research group in Perth did this experiment in early 2009. They rounded up a few athletes and tested their sprinting with and without a stretching regimen between sprints.39 The results of the tests were clear: “There was a consistent tendency for repeated sprint … times to be slower after the static stretching.” In other words, if you want to perform in a sprinty sport, you might not want to stretch right before getting your cleats dirty.
There are many possible mitigating factors here.40 However, the complexities only emphasize the absurdity of the legions of people who have an oversimplified faith that stretching is important. The evidence is clear that stretching is generally pointless for enhancing performance, and possibly worse. Scientific reviews keep reporting the same conclusion.41 Maybe eventually this news will reach amateur athletes? But don’t hold your breath.
In the face of so much discouraging evidence, it makes sense to assume that sport itself provides all the “stretching” one needs. The late Mel Siff:
It is almost heretical to question this stretching doctrine, yet it is important to disclose that there is no research which proves categorically that there is any need for separate stretching sessions, phases or exercises to be conducted to improve performance and safety. To appreciate this fact, it is useful to return to one of the clinical definitions of flexibility, namely that flexibility refers to the range of movement of a specific joint or group of anatomical tissues. Moreover, flexibility cannot be considered separate from other fitness factors such as strength and stamina. There is no real need to prescribe separate stretching exercises or sessions, since logically structured training should take every joint progressively through its full range of static and dynamic movement. In other words every movement should be performed to enhance flexibility, strength, speed, local muscular endurance and skill, so that separate stretching sessions then become largely redundant.
~ Facts and fallacies of fitness, by Mel Siff, p. 123
Siff’s sensible minimalism — from 1988 — stands in stark contrast to a much more common and marketable “flexibility first” approach, an approach that just happens (coincidence, I’m sure!) to give coaches, trainers and therapists something to be expert about: the idea that athletes must make a point of increasing flexibility first (by whatever stretching method), and then train for the strength and coordination to exploit this marvelous new range of motion. That picture is quite likely to be exactly backwards.
A lot of stretching happens in an athletic context for the reasons discussed above, but they all have something in common. The underlying, general assumption, almost always unstated, goes like this:
Stretching is a major component of fitness, on par with strength and endurance.
That idea breaks down into specific claims that don’t hold up under scrutiny, but no matter how effective that debunking, almost everyone who like stretching will continue to assume that it’s different for “serious” athletes or athletes who seem to need more flexibility: gymnastics, dance, martial arts, circus arts, and so on. And yet it’s likely that even for those functional goals stretching is not actually anywhere near as important as we have believed, and maybe not even important at all. If all this information is taken to heart, it should be clear that a “serious” athlete might actually want to avoid stretching. They have a lot of other training to do that is definitely more important — and which will also achieve flexibility.
Until fairly recently, there were few major examples of elite athletes rejecting stretching, but that’s changing. The best recent example I know of is that the Australian Ballet has purged stretching; instead, it’s all about training for strength training throughout the full joint range. The Australian Ballet has written about their experience with this: same or better performance, fewer injuries. Wow.
Dogma is powerful. When there’s a long tradition of doing things a certain way, it can be extremely difficult for people to accept that it might not be necessary. For years, I have regularly gotten angry email from martial artists, always sneering smugly about how I obviously know nothing because, clearly, elite martial artists know that they have to stretch. Maybe. I doubt it, and I can see which way the wind is blowing on this, but I honestly don’t know.
I do know the power of dogma. I know how many times in sports history traditional practices have been overturned and replaced by updated beliefs that were required to break new records.
And in fact I do have some personal experience with martial arts, and I know that not every martial artist is flexible or thinks they need to be. My most memorable example was a grizzled old practitioner of Aikido — the most formidable martial artist I ever met, and also the least flexible. He seemed flexible, but it was all in how he used the rather stunted range of motion he had. He worked within his limitations like an artist — a martial artist — and you would never even haved guessed he was so stiff unless you spent time with him in training.3 We never stretched much in that dojo, and an MMA club — with some very competitive members — also never did any stretching.
As the years tick by, I predict that there will be more and more stories about elite athletes who no longer stretch — but still kick ass.
Why is it that many Kenyans don’t stretch? Why was legendary coach Arthur Lydiard not a fan of stretching? Why does Galloway say, “In my experience runners who stretch are injured more often, and when they stop stretching, the injuries often go away”?
~ Bob Cooper, Runner’s World Magazine4
I am a soccer referee, and mostly by happy accident began substituting what you call “mobilizing” for various stretches prior to my matches, and I find this does an excellent job of stimulating the muscles, whereas after only stretching I still seem to be tight for the first several minutes. Then I read this article, which corroborates what I have found in practice!
~ Carlos Di Stefano, soccer referee (reader feedback)
About Paul Ingraham
I am a science writer in Vancouver, Canada. I was a Registered Massage Therapist for a decade and the assistant editor of ScienceBasedMedicine.org for several years. I’ve had many injuries as a runner and ultimate player, and I’ve been a chronic pain patient myself since 2015. Full bio. See you on Facebook or Twitter.
Specifically about stretching:
- Stretching Injury — How I almost ripped my own head off! A cautionary tale about the risks of injury while stretching
- A Stretching Experiment — What happens when you stretch your hamstrings intensely for several minutes a day in a steam room?
- IT Band Stretching Does Not Work — Stretching the iliotibial band is a popular idea, but it’s very hard to do it right, and it’s probably not worth it
- Stretching for Pain (and Pleasure) — Is stretching a treatment for chronic pain?
- Stretching for Flexibility — You can increase your flexibility by stretching, for whatever it’s worth… but what is it worth?
- Mobilize! — Dynamic joint mobility drills are an alternative to stretching that “massage with movement”
- Quite a Stretch — Stretching science has shown that this extremely popular form of exercise has almost no measurable benefits
- The Unstretchables — Eleven muscles you can’t actually stretch hard (but wish you could)
- Why Do Muscles Feel Stiff and Tight? — Maybe your range of motion is actually limited, or maybe it just feels that way
- Post-Exercise, Delayed-Onset Muscle Soreness — The biology & treatment of “muscle fever,” the deep muscle soreness that surges 24-48 hours after an unfamiliar workout intensity
- The Tyranny of Yoga, Meditation, and Mindfulness — Do you really need to try them? How much do they matter for recovery from conditions like low back pain?
- Strength Training for Pain & Injury Rehab — Why building muscle is easier, better, and more important than you thought, and its role in recovering from injuries and chronic pain
Injuries where stretching might play some role in rehab… or where its role particularly needs debunking:
- plantar fasciitis
- Achilles tendinitis
- muscle strains
- patellofemoral pain
- IT band syndrome
- tennis elbow
This article was originally part of a much larger article dating back to the first version in August 2000. Twenty years later, I split that big ol’ article up in August 2020, giving this sub-topic new life on its own page.
Aug 7, 2020 — Editing: Content is like-new after being extracted from stretching mega-article and converted into a stand-alone article on the sub-topic of athletic goals for stretching.
April — More content: Added some examples of stretching being rejected by elite athletes. [Updated section: Last word: Stretching is not a ‘pillar’ of fitness.]
January — New section: No notes. Just a new chapter. [Updated section: Reason #4: Stretching to recover from injury.]
2017 — New section: Discussion of four ways that stretching may cause harm, especially for medically vulnerable people. [Updated section: In fact, stretching can actually cause injuries.]
2017 — Science update: Added preliminary discussion of evidence on the prevention of muscle strains. (More to come on this topic.) [Updated section: Reason #3: Stretching to prevent injury.]
2017 — Revised: A heavy edit for clarity and brevity. [Updated section: Reason #2: Stretching to prevent soreness (or speed recovery from it).]
- I spent a decade in clinical practice as a massage therapist, routinely asking my patients about their stretching beliefs and habits, among many other things. These days I am a full-time writer on these topics with a global audience, so I heard vastly more about stretching from readers by email than I ever heard from my patients back in the day. I have a great bird’s eye view of popular opinions about stretch. Professionals send me a lot of mail as well, so I get a lot of exposure to their opinion’s. Are they more educated about stretch? You’d sure hope so, but that hasn’t really been my impression, to be honest — it really seems like everyone is just repeating things they heard other people say. Professionals just hear and repeat even more.
- More evidence on this is coming, but meanwhile there’s an interesting general principle at work here that is worth pointing out: these goals are proven to be impossible either straightforwardly by an evidence of absence, or less obviously but almost as certainly by a preponderance of evidence of minor efficacy. Proof of the existence of a trivial benefit damns with faint praise, and proving that something barely works is literally almost the same as proving that it doesn’t work at all. This is chronic problem with many allegedly effective treatments and therapies: they may work a little, but they fail to impress. Stretching suffers from this problem in spades.
- His wrist ROM was especially memorable: it was like his hands were welded onto the end of his forearms. He once showed me how far he could bend his wrist back, which was not at all. Aikido uses a lot of wrist locks, so his sturdy and inflexible wrists made him almost impervious to those … but with no detectable functional deficit either.
Cooper, Bob. “The Rules Revisited.” Runner’s World. September, 2009. p. 59.
- 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 ❐ Researchers looked at more than 4500 studies before choosing about 100 to look at more carefully. The found “overwhelming evidence” of “no significant effect,” and that is certainly no surprise for anyone who had been watching stretching science over the years.
- Damasceno MV, Duarte M, Pasqua LA, et al. Static Stretching Alters Neuromuscular Function and Pacing Strategy, but Not Performance during a 3-Km Running Time-Trial. PLoS One. 2014;9(6):e99238. PubMed #24905918 ❐ PainSci #53972 ❐ The conclusion reproduces and builds on similar evidence. It wasn’t a huge negative effect, but absolutely in the wrong direction! An epic fail for stretching.
- Lowery RP, Joy JM, Brown LE, et al. Effects of static stretching on 1-mile uphill run performance. J Strength Cond Res. 2014 Jan;28(1):161–7. PubMed #23588487 ❐
There’s more to say about this one, and Alex Hutchinson did, but here’s the nasty nugget: pre-run stretching caused an eight percent drop in performance in a one-mile uphill run. Yikes!
- Soligard T, Myklebust G, Steffen K, et al. Comprehensive warm-up programme to prevent injuries in young female footballers: cluster randomised controlled trial. BMJ. 2008;337:a2469. PubMed #19066253 ❐ PainSci #56160 ❐ In 2008, Norwegian researchers compared injuries in over a thousand female footballers who participated in such a warmup for a season, to another several hundred who didn’t. The athletes with the warmup had fewer traumatic injuries, fewer overuse injuries, and the injuries they did have were less severe. Static stretching was not part of the warmup. “Active stretching” was … but “active stretching” is what I would call “mobilizations” — doing moving lunges, for instance — as opposed to the kind of static or passive stretching that most people think of when they think of stretching.
- Soligard T, Nilstad A, Steffen K, et al. Compliance with a comprehensive warm-up programme to prevent injuries in youth football. Br J Sports Med. 2010 Sep;44(11):787–93. PubMed #20551159 ❐ PainSci #54998 ❐
Researchers found that injury rates were significantly lower in soccer (football) teams that diligently performed warmup exercises (“The 11+”, a warmup program recommended by FIFA, which notably does not include stretching). On the one hand, there was not much difference between a little warming up (low participation) and a bit more warming up (average participation). But players and teams that did an especially good job of warming up (“twice as many injury prevention sessions”) got solid results: “the risk of overall and acute injuries was reduced by more than a third among players with high compliance compared with players with intermediate compliance.” That extra enthusiasm went a long way!
A related example
When I was studying to become a massage therapist, our most scientifically literate instructor dared to share a recent research paper with the class (something no other instructor ever did, which is an ugly truth about my training). The study suggested that massage therapy has no effect on the phenomenon of delayed-onset muscle soreness (Tiidus). This was heretical! Most of the class reacted angrily to this attempt to tip over one the sacred cows of massage therapy, and the hapless instructor was nearly shouted out of the classroom.
What amazed me most about that was that the belief the students were defending was new to them, based only on what they’d heard from instructors in their first year of classes. And yet it was already essential to their self-image as budding health professionals, a “fact” that they planned to use to promote their services someday. It doesn’t take much for dogma to settle in!
This incident made quite an impression on me, and is partly responsible for my own journey from credulity to skepticism.
- Berrueta L, Muskaj I, Olenich S, et al. Stretching Impacts Inflammation Resolution in Connective Tissue. J Cell Physiol. 2016 Jul;231(7):1621–7. PubMed #26588184 ❐ PainSci #52915 ❐
In a previous experiment, these researchers claim to have found evidence that stretching successfully treated inflammation and pain in rats. In this follow-up experiment, they looked more closely at the biology, measuring markers of inflammation: inflammatory lesion thickness, neutrophil count, resolvin (RvD1) concentration. They believe this shows a “direct mechanical impact of stretching on inflammation-regulation mechanisms within connective tissue.” It’s intriguing science for sure, but replication in humans is needed before we get too excited about it.
- Peterson AM, Pedersen BK. The anti-inflammatory effect of exercise. J Appl Physiol. 2005 Apr;98(4). PainSci #52512 ❐
- It’s just one study. We don’t actually know that what Berrueta et al found is for real, and we won’t know until it has been replicated. More importantly, this was a demonstration of an effect on connective tissue, not muscle — and while muscle is full of connective tissue, DOMS is much more of an issue with muscle than connective tissue, and it is far from guaranteed that an effect on connective tissue has anything to do with DOMS.
- 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. PubMed #9764443 ❐
From the abstract: “There was no difference in the reported variables between experiments one and two. It is concluded that passive stretching did not have any significant influence on increased plasma-CK, muscle pain, muscle strength and the PCr/P(i) ratio, indicating that passive stretching after eccentric exercise cannot prevent secondary pathological alterations.”
- Cheung K, Hume P, Maxwell L. Delayed onset muscle soreness: treatment strategies and performance factors. Sports Med. 2003;33(2):145–64. PubMed #12617692 ❐
From the abstract: “Cryotherapy, stretching, homeopathy, ultrasound and electrical current modalities have demonstrated no effect on the alleviation of muscle soreness or other DOMS symptoms.”
- Weber MD, Serevedio FJ, Woodall WR. The Effects of Three Modalities on Delayed Onset Muscle Soreness. Journal of Orthopaedic & Sports Physical Therapy. 1994;20(5):236–42. PubMed #9512831 ❐
Forty women were subjected to intense training of the biceps and brachilias muscles, until they were sore, and then treated with one of four treatments for DOMS: massage, TENS (electrical stimulation), and ergometry (basically light exercise, to stimulate metabolic activity), and rest. Treatment were given immediately after and then 24 and 48 hours after. There was no difference in the results for any of the women.
- Herbert RD, de Noronha M, Kamper SJ. Stretching to prevent or reduce muscle soreness after exercise. Cochrane Database Syst Rev. 2011;(7):CD004577. PubMed #21735398 ❐
Does stretching help either before or after exercise to reduce soreness? Nope. This large review of eleven small scientific studies, and one huge one, wrapped up with a clear thumbs down:
The evidence from randomised studies suggests that muscle stretching, whether conducted before, after, or before and after exercise, does not produce clinically important reductions in delayed-onset muscle soreness in healthy adults.
The evidence was “low to moderate,” with “moderate to high” risk of bias, which means most of the researchers were probably hoping to find that stretching does help DOMS … but even with that likely bias, they still didn’t find what they were looking for.
The big study was technically positive, finding an average drop in soreness of four points on a 100-point scale, which is basically meaningless. The variation between the results for individuals is undoubtedly greater than that.
- Hart L. Effect of stretching on sport injury risk: a review. Clin J Sport Med. 2005 Mar;15(2):113–113. PubMed #15782063 ❐
OBJECTIVE: Effect of Stretching on Sport Injury Risk: a Review To assess the evidence for the effectiveness of stretching for the prevention of injuries in sports.
DATA SOURCES: MEDLINE (1966 to September, 2002), Current Contents, Biomedical Collection, Dissertation Abstracts, the Cochrane Library, and SPORTDiscus were searched for articles in all languages using terms including stretching, flexibility, injury, epidemiology, and injury prevention. Reference lists were searched and experts contacted for further relevant studies.
STUDY SELECTION: Criteria for inclusion were randomized trials or cohort studies of interventions that included stretching compared with other interventions, with participants who were engaged in sporting or fitness activities. One author identified 361 articles reporting on flexibility, methods and effects of stretching, risk factors for injury, and injury prevention, of which 6 articles fulfilled the inclusion criteria for meta-analysis.
DATA EXTRACTION: Three independent reviewers blinded to the authors and institutions of the investigations assessed the methodologic quality of the studies (100-point scale) and reached consensus on disagreements. Details of study participants, interventions, and outcomes were extracted. Weighted pooled odds ratios were calculated for effects of interventions on an intention-to-treat basis.
MAIN RESULTS: Reduction in total injuries (shin splints, tibial stress reaction, sprains/strains, and lower-extremity and -limb injuries) with either stretching of specific leg-muscle groups or multiple muscle groups was not found in 5 controlled studies (odds ratio [OR] 0.93; 95% CI, 0.78 to 1.11). Reduction in injuries was not significantly greater for stretching of specific muscles (OR, 0.80; CI, 0.54-1.14) or multiple muscle groups (OR, 0.96; CI, 0.71-1.28). Combining the 3 ratings of methodologic quality, median scores were 29 to 60/100. After adjustment for confounders, low quality studies did not show a greater reduction in injuries with stretching (OR, 0.88; CI, 0.67-1.15) compared with high quality studies (OR, 0.97; CI, 0.77-1.22). Stretching to improve flexibility, adverse effects of stretching, and effects of warm up were not assessed by appropriate intervention studies.
CONCLUSION: Limited evidence showed stretching had no effect in reducing injuries.
- 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. 2008 Apr;36(4):663–670. PubMed #18337359 ❐
- Pereles D, Roth A, Thompson DJ. A Large, Randomized, Prospective Study of the Impact of a Pre-Run Stretch on the Risk of Injury in Teenage and Older Runners. USATF.org. 2011 Jun 15. PainSci #55243 ❐
- Lauersen JB, Bertelsen DM, Andersen LB. The effectiveness of exercise interventions to prevent sports injuries: a systematic review and meta-analysis of randomised controlled trials. Br J Sports Med. 2014 Jun;48(11):871–7. PubMed #24100287 ❐ PainSci #53226 ❐
- They thought strengthening looked good, but based their very positive-sounding conclusions on only four studies of dubious quality and relevance.
- 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. PubMed #26642915 ❐ PainSci #52916 ❐
This wide-ranging review concluded that “studies indicate a 54% risk reduction in acute muscle injuries associated with stretching.” This is at odds even with previous reviews by some of the same key authors. For instance, while McHugh et al were optimistic in 2010, they based their optimism on speculation and characterized the evidence as limited: “For example, there is a good rationale for why stretching could impact the risk of sustaining a muscle strain injury, but the effect of stretching on muscle strain injuries has not been adequately researched in sports with a high incidence of muscle strains.” That was just six years prior, with almost no relevant new evidence in the interim.
Nearly identical evidence. One review calls it inadequate. The other says stretching prevents muscle strain.
So I guess this question is not settled. 😜
- For instance, if stretching reduces the chances of tearing a muscle, you’d need to stretch the muscles most likely to tear, which are the big muscles of the thighs: quadriceps, hamstrings, and adductors (groin). Hamstrings are likely to be included in most stretching regimens. Quadriceps are often included, but not always. Adductors are often missed or given minimal attention. If stretching reduces the risk of muscle strains, you’d have to make a point of stretching all three — and that’s only the most common strain locations.
- Academy of Medical Royal Colleges. Exercise: The miracle cure and the role of the doctor in promoting it. AOMRC.org.uk. 2015 Feb. PainSci #53672 ❐
This is the primary authoritative source of the quote “exercise is the closest thing there is to a miracle cure.”
- Gopinath B, Kifley A, Flood VM, Mitchell P. Physical Activity as a Determinant of Successful Aging over Ten Years. Sci Rep. 2018 Jul;8(1):10522. PubMed #30002462 ❐ PainSci #53004 ❐
If you want to age well, move around a lot!
We already know that physical activity reduces the risk of several of the major chronic diseases and increases lifespan. “Successful aging” is a broader concept, harder to measure, which encompasses not only a reduced risk of disease but also the absence of “depressive symptoms, disability, cognitive impairment, respiratory symptoms and systemic conditions.” (No doubt disability from pain is part of that equation.)
In this study of 1584 older Australians, 249 “aged successfully” over ten years. The most active Aussies, “well above the current recommended level,” were twice as likely to be in that group. Imagine how much better they’ll do over 20 years …
- Research shows strength training is a much more efficient form of exercise than most people realize, and almost any amount of it is much better than nothing. You can gain strength and all its health benefits fairly easily. For more information, see Strength Training Frequency: Less is more than enough: go to the gym less frequently but still gain strength fast enough for anyone but a bodybuilder.
- The “Upper-Crossed Syndrome” (UCS) sounds impressively technical. It is the apex of clinical storytelling about posture in therapy culture, and the prototypical “muscle imbalance” theory, and yet it basically just means slouching: head and shoulders forward, mostly, with several complicated assumptions about its causes and consequences. With UCS, your muscles are presumed to be like dysfunctional ship’s rigging: some are weak and loose (“inhibited”), while others are too strong and tight (“facilitated”). Viewed from the side, you can draw diagonal lines between these groups that cross. (There’s a Lower-Crossed Syndrome as well.) Dr. Janda was a pioneer and did good work with the information he had at the time, but he was probably mostly wrong about UCS; muscle imbalance theories like UCS have not done well over the last couple decades. For more information, see the upper-crossed syndrome section of my posture article.
- Tumminello N, Silvernail J, Cormack B. The Corrective Exercise Trap. Personal Training Quarterly. 2017 Mar;4(1). PainSci #52905 ❐
The authors decisively but gently tip over the most sacred cow of personal training and therapy: corrective exercise, which is grounded in the assumption that there is something in-correct about patients — fragile, weak, or uneven — which must be fixed by sufficiently expert and precise exercise prescription. Exaggerating the importance of defect-correction is actually dangerous for the patient (nocebic): “When clients are told such things about themselves from an authority figure (as they might be during some corrective exercise evaluations), that this potentially makes one’s clients less resilient and more prone to injury and pain.” Translation sans diplomacy: *stop #%&^ telling patients they are fragile and weak!*
The corrective exercise trap is also about overconfidence in the value of allegedly advanced rehab exercise, when the evidence is overwhelming that corrective exercise is no better than general exercise. “The danger here” — the trap! — “is that many fitness professionals might end up making their training process more about a formalized evaluation procedure and less about good personal training.”
- If an injury causes more stubborn loss of ROM by the mechanism of contracture or derangement of the bone or cartilage in a joint, stretching is going to be futile.
- Ingraham. IT Band Stretching Does Not Work: Stretching the iliotibial band is a popular idea, but it’s very hard to do it right, and it’s probably not worth it. ❐ PainScience.com. 2631 words.
- Radford JA, Landorf KB, Buchbinder R, Cook C. Effectiveness of calf muscle stretching for the short-term treatment of plantar heel pain: a randomised trial. BMC Musculoskelet Disord. 2007 Apr;8:36. PubMed #17442119 ❐ PainSci #52975 ❐
This trial of stretching for plantar fasciitis made an effort to blind the participants. That is, the 92 study subjects didn’t know what treatment was being tested, reducing the likelihood of bias in reporting on the results. This was achieved by adding sham ultrasound to both the treatment and control groups, a good strategy. After two weeks, unfortunately there was no difference between the groups: “a two-week stretching program provides no statistically significant benefit in ‘first-step’ pain, foot pain, foot function or general foot health compared to not stretching.”
It could have been a larger, longer study, sure, but 92 feet is quite a decent sample size for studies of this kind of thing. And although stretching benefits might ramp up over time, that’s probably wishful thinking, and you’d certainly hope to see clearer signs of progress after two weeks of diligent stretching.
- Malliaropoulos N, Papalexandris S, Papalada A, Papacostas E. The role of stretching in rehabilitation of hamstring injuries: 80 athletes follow-up. Med Sci Sports Exerc. 2004 May;36(5):756–9. PubMed #15126706 ❐
About 40 Greek athletes who stretched more intensively recovered faster than those who stretched more lackadaisically (and the effect is probably not limited to the Hellenic people). How much faster did they recover? They regained their range of motion about 22% sooner (5.6 days instead of 7.3), and their “rehabilitation period” was about 12% shorter (13.3 days instead of 15 days). The researchers reported that this was of “great importance in treating muscle strain injuries.” I’m not quite so thrilled by those numbers: getting back in the game about 36-hours sooner is not nothing, but I wouldn’t call it greatly important. One could easily argue that a wee improvement in healing time isn’t worth the risk of injury, or even the tedious routine of stretching. One could also argue that they really should have compared stretching to other kinds of rehabilitative exercise, and the difference probably would have disappeared.
- HSD is a bucket diagnosis for people with symptomatic hypermobility, but without a clear diagnosis of a connective tissue disorder, like EDS or Marfan syndrome.
- “The essential difference between HSD and hEDS lies in the stricter criteria for hEDS compared to the HSD.” But it’s very tricky, and those criteria all very new (see the 2017 EDS International Classification). Ironically, as of 2017, the one sub-type of EDS that does not have an identified genetic cause is the hypermobile EDS (hEDS).
- Scheper MC, de Vries JE, Verbunt J, Engelbert RH. Chronic pain in hypermobility syndrome and Ehlers-Danlos syndrome (hypermobility type): it is a challenge. J Pain Res. 2015;8:591–601. PubMed #26316810 ❐ PainSci #52758 ❐ Hypermobility is “highly prevalent among patients diagnosed with chronic pain.”
- There’s actually an entire stretching book that is largely based on this idea — but that book is conspicuously full of armchair science, and no actual evidence that the ideas are true.
- From Kay et al: “The detrimental effects of static stretch are mainly limited to longer durations (≥60 s) which may not be typically used during pre-exercise routines in clinical, healthy or athletic populations. Shorter durations of stretch (<60 s) can be performed in a pre-exercise routine without compromising maximal muscle performance.”
- Beckett JR, Schneiker KT, Wallman KE, Dawson BT, Guelfi KJ. Effects of Static Stretching on Repeated Sprint and Change of Direction Performance. Medicine & Science in Sports & Exercise. 2009 Jan 5.
- The most obvious wrinkle is that the negative impact of static stretching on sprinting might be short term — were the runners slowed down for only ten minutes? Twenty minutes? As much as sixty? Another important consideration is that the potential therapeutic effects of stretching — still remarkably unproven at this late date in history, but still hypothetically possible — could conceivably outweigh the relatively small cost of being slowed down. For instance, if (big if) stretching significantly reduced the risk of a muscle strain, would that risk reduction be worth the cost to sprinting speed? Probably! If.
- Baxter C, Mc Naughton LR, Sparks A, Norton L, Bentley D. Impact of stretching on the performance and injury risk of long-distance runners. Res Sports Med. 2017;25(1):78–90. PubMed #27912252 ❐