Tight hamstrings in runners: why lifting beats stretching

You're listening to the Restoring Human Movement podcast, where movement experts discuss the latest evidence-based practices to help you and your clients move with mastery. Hey everyone, this is Dr. Mandy for the Restoring Human Movement podcast. I am your handy running person, distance running, ultra running, trail running. Thank you for joining the movement movement. I just got back from a workout and I'm an ultra runner, so I don't have a race on the calendar. Frankly, I'm pretty lazy about workouts right now. But just got back and actually did some stretching, which I don't usually do. And it got me thinking about the kind of pros and cons of stretching, especially for trail and ultra athletes, and some common beliefs and myths that I hear from my patients.

So today we're going to be going over the two most common beliefs that I see about stretching and injury. And then we're going to go over some pros and cons. But just so you know, this is mostly my anecdotal experience, meaning what I see in clinic and in practice and what I've experienced myself as an ultra and distance athlete. And if you are in love with stretching, you absolutely love it, can't get enough of it, and it doesn't hurt you and it feels good. Keep doing it. Just because I don't stretch very often doesn't mean you have to do the same thing I am. Everybody's bodies are created differently.

So you should listen to your own and act accordingly. All right, jumping straight into the two most common beliefs that I see regarding stretching and injury. And belief number one, by far the most common, is that stretching will solve somebody's injury. In my experience, this is mostly not true. This will not solve most injuries and often actually makes it worse depending on what your injury is. So for example, if you strained your hip flexor, say you were doing some sprints, you're like me, you haven't done sprints in many years, and all of a sudden your hip flexor feels like it's a little bit torn, stretching will not help, especially not in the hip flexor that you just maybe tore.

In part because a strain of a tendon or a muscle is a overstretch injury. So you basically put your muscle or tendon into a stretch position that it was not prepared to take, and usually that requires some load to actually tear or strain the area. There are grades of tear. We will not go into it. There are plenty of our own podcasts that do, or you can look up grades of tear. But regardless, it's mostly an overstretch injury, and most of the time it has a fair amount of load going through the structure. And so seems to play out logically, if you stretch an overstretch injury, it's not going to make it feel better, and it will probably make it feel worse.

Now the hard part about that is the day after you strain something, it feels really stiff. It's your body's way of protecting the area that's strained, and so naturally you want to stretch it, but don't in that immediate phase. The other common injury that I see where people stretch it and it feels worse afterwards is any sort of nerve irritation. Nerves actually do stretch a little bit, but they stretch much less than muscles or tendons or even most ligaments, and they don't tolerate it as well as those other structures, in part because nerves are more sensitive to changes like that, and everybody's hit their funny bone and gets the tingles down their hand, and maybe you didn't even hit it that hard.

That just shows that the irritability threshold of a nerve is different than, say, bumping your quad muscle on the side of the table at the same amount of force. With that, though, it's very similar to strains in the sense that a nerve irritation will feel stiff most of the time. So most commonly this shows up in hamstring stiffness, at least anecdotally. I see a lot of distance runners and ultra runners especially, not entirely sure why this is biased towards ultra runners, but lots of ultra runners come in and they're like, yeah, my hamstrings just feel kind of stiff all the time, and sometimes they hurt, and sometimes that pain kind of radiates down.

Maybe it's on one side, maybe it's on both, and then they tell me, well, I've been doing a lot of stretches for it because it feels stiff, and it hasn't helped at all, and sometimes when I stretch, it actually feels worse afterwards, but then it stiffens up again, so I keep stretching it. At some point, I have to ask them, well, why are you doing that over and over if it's not helping? And it always comes back to, well, it feels stiff. Sometimes stiffness is the body's way of protecting the area, so if you're insulting the area by stretching it again, and it keeps re-stiffening, it's going to keep protecting the area because you're doing something to piss it off.

This is a prime example where knowledgeable treatment or strength training even, or rest, or relative rest, can be a lot more effective than stretching, and stretching can actually be counterproductive. Now, this is difficult through traditional methods of musculoskeletal injury care, so I've been treated by athletic trainers and other chiropractors, other rehab chiropractors, too. I've been treated by people who do a lot of stretching, I've been treated by PTs, gone through most of the traditional gambit of injury care, and it's a very easy logic trap to get into where something stiff. It feels stiff to another person even, like, hey, I'm lifting up your leg and your leg doesn't go very far. We should fix that. And then they do a lot of stretching.

So people get trapped even when the practitioner has the best intentions in mind and they see this functional thing that needs to change. And so they do the thing that they think will help it, and in fact, it either keeps it around or makes it worse. This seems to be very, very common if you're working with someone who doesn't really understand the demands of ultra running or trail running. Also, just a quick aside here, I am a real person, not just the podcaster behind the microphone. So I work when trail runners, distance runners, ultra runners mostly. And so if you need help, shoot us an email or contact us below. All the information's in the description.

So in summary, as a response to the belief that stretching will solve an injury, I mostly say, no, it won't. The only way that it can, that I've seen, and I've experienced this myself, it didn't solve it, but it did help it, is a chronic kind of ache in a joint. So this is not an acute injury where you're bombing downhill and all of a sudden your hip hurts the next day. This is, hey, my knee's been hurting for about a year and it's not really responding to much, but when after I stretch, it feels a little bit better. Again, it's probably not going to solve it. I've heard some stories where some people feel like it solves it. That's great. But for most, it doesn't solve it, but it may actually make it feel better. But make sure that it is not a strain, make sure that it is not tendon or nerve irritation, and then you can try it more safely and see if it helps you out. The other most common belief I see, and this is all over the internet, depending on what circles you are following on social media, is that stretching will prevent injury. So not just treat injury, but prevent it, which would be fantastic. If that were the case, I would be out of a job. Everyone would be feeling good and taking yoga classes or Pilates classes and would never be injured, which, I mean, I like my job, but that would be great, right?

Stretching can help not get you into an injury cycle, but anecdotally, this only really seems to go so far. So for people who are regular, you know, can touch your toes, can't put your foot behind your head, it doesn't seem to make a huge difference. And then for folks who are hypermobile, so they bend a lot or they have conditions like Ehlers-Danlos syndrome, anything that means that your passive tissues, like your ligaments and cartilage and things like that, move a lot more than the normal person. Stretching actually hurts them a lot, even though they, again, feel like they need to stretch, in part because they already have so much passive laxity in their body that adding more through stretching decreases the stability range of their joints and muscles. The people who can benefit from stretching in terms of a preventative measure are the folks who have been super, super stiff for a super long time, and all of a sudden they're having fallout from a direct, hey, I don't have the range of motion to perform the task at hand. So the classic example in trail running, you're a 60-year-old dude, you've been trail running since you were 20 or younger, you never stretch, you don't do any strength training, none of that stuff, and you're trying to do a fast race where there's a lot of downhill involved.

So if you have no range of motion in your hips and you never really have, and those structures are just stiff in general, and all of a sudden you're bombing downhill, your hip might hurt because you're exposing it to a range it's not used to. That being said, if you stretch some beforehand chronically, so you're stretching for multiple weeks at a time, that can help loosen up the structure, and even though you are putting load through it when you're running downhill, it may tolerate the stretch better because you've prepared it to access that range. All of this being said, and this is both my own bias and where the science seems to be pointing right now, stretching does not prevent injury as much as other measures. So fueling is huge. We've talked about that over and over again, avoiding REDS, relative energy deficiency in sport, fueling after workouts, sleeping enough, super cliche, but it is true, and then managing your training load. So this is where working with a coach can really help, but it's the classic adage, don't do too much too soon. So injuries can pop up very classically when you're running 10 miles a week, and all of a sudden you sign up for 100 miler, and you need to get up to 45, 50, and you do it in like three weeks. That one's fairly obvious, but it also can apply to intensity. So for myself, for example, today I did a workout where I was getting down towards 520 pace, and I haven't done that in a couple of years. I used to do it all the time when I was running track in NCAA, but I haven't done that in a while, and so what I am not going to do is keep doing workouts like that two or three times a week. This was my first one in years. The too much too soon adage is not just for mileage. It also goes for intensity. So if you are reintroducing workouts into your routine, don't go ham. In terms of strength training, strength training is often overlooked in runners. They think it's going to make them bulky, which newsflash here. It will not, as assuming you are doing the right type of strength training, and even if you're doing quote-unquote the wrong type, i.e. you're trying to do the same type of strength training that guys who are trying to bulk are doing, even if you're doing that, you're not going to bulk as much as them because you're putting your body through so much cardio. It actually changes the enzymatic response to hypertrophy, which is a whole different thing. You can look at some of Keith Baar's work, that's B-A-A-R. He's studied some of this in particular in terms of how to sequence your strength training and your cardio to access the most or least hypertrophy. But either way, strength training can help with injury prevention. Again, I'm very biased towards this, but you need to have stability in multiple planes of motion and be able to handle loads of varying degrees, varying speeds, of varying dynamicness, I suppose. So you need to be able to hop over the rock when it comes at you 80 miles into a race, and you need to be able to handle tight switchbacks even when you're tired. Those sorts of things really help mitigate the, hey, I just fell off the switchback, or even it helps mitigate the, hey, I have this knee pain after doing a ton of switchbacks and I don't really know why. Having the stability, your body's own support to support the passive structures like the stuff in your joints that can't really contract or help support in an active way is really important.

So strength training, strength training, strength training. I am super biased towards this, but I'm biased towards it for a reason. We're going to wrap this up fairly soon, but just quick pros and cons of stretching pros, it feels good. It's very nice to mentally relax and recenter after a run, especially a hard workout. And generally, if you're not pissing off an injury, like I said, like nerve irritation or an overstretch injury, it's nice to feel less stiff, especially if you're somebody who works in a sedentary job. There is an aspect of use it or lose it. So this doesn't go to the full extreme of, say, you haven't trained for a year and all of a sudden you're completely out of shape. But stretching, if you don't stretch all the time, you will probably become less stretchy. And at some point that will plateau on the bottom to your body's natural unstretchiness. For some people, that's an okay range and it doesn't really affect them. And for some people, they're really stiff and they would benefit from some stretching as long as it's not hurting anything. Some cons of stretching. Some studies, these are a few, and it does become more relevant for speedier runners, people who are trying to do shorter track races or really, really fast stuff. Some studies show that it decreases running economy or running efficiency. Think of if you're trying to be a spring and you stretch out the spring and you get it to the point where you stretch it out so much that the spring is actually longer than it was before. A similar kind of thing happens in your muscles and tendons. So your muscle is the part that shortens or contracts and your tendons are just kind of along for the ride. So the muscles in the middle, tendons on each side. Tendons can't contract, but they can stretch in accordance with how long or short the muscle is.

So if you're trying to be an efficient spring, like you want your muscle to shorten and create force quicker, stretching it out isn't necessarily going to help because then your muscle has to overcome more passive length in the tendons. This is on the margins, so take it with a grain of salt. But for folks who may be listening that are doing events 400 and below, this will be much more relevant for you. And then this is also relevant for folks who like doing a lot of plyometrics. Runners, I know a lot of people are starting to get into both running and HIIT workouts or CrossFit. If your goal is to do plyometrics and do them quickly and do them well, stretching to an extreme degree might not be helpful for your energy return there. And then the big con, again, biased, is that stretching can take away time that you could be strength training for injury prevention much more effective. Or you could be running more if you're somebody who needs to be increasing your volume or eating and recovering and sleeping. For me personally, I stretch once in a blue moon. And by that, I mean maybe once or twice in a month, honestly. But I have found over time that I am moving away from the don't stretch, it doesn't do anything mindset. And I am finding it nice in part because of that mental aspect of being able to center yourself after a workout. But I have become stiffer over the years since I was stretching more in the past. And I would like to not be like that. And that's in part because some of my job requires me being looser. Like I'm picking up people's legs and stuff and squatting down in fun positions and all that. And that requires some amount of laxity and passive stretch in my joints in order for my body to stay healthy through all of those movements throughout the day. So I am starting to come around to some stretching. I still don't think it does a ton for any of my old injuries. But I will say when I had kind of a knee ache thing going on, it did help to stretch out my quad over time. And so I can't be a total hater of stretching, I guess. But all this to say, if you find benefit in stretching, go for it. If you find benefit in the sense of it doesn't hurt anything, go for it. But if you're using it as your only measure to treat an injury or prevent an injury and it doesn't seem to be doing that, you need to explore other options, at least in conjunction with stretching, if not instead of stretching. If you need help with that, shoot us an email. Info is below. And if you totally disagree with me, that is fine. But I would love to hear your opinion and get your take on why you love or hate stretching. Check out the rest of our podcast below. We have tons and tons and tons of episodes by now on all things injury, some stuff you probably have never heard of before, and a lot of stuff you have, but going into more detail and nuance than other platforms.