Dynamic stretching doesn’t hurt (or help) running performance


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- Alex Hutchinson (@sweatscience)


Back in 2010, researchers at Florida State published a study showing that trained distance runner became about 5% less efficient and covered 3% less distance in a time trial if they did static stretching before the run. This was significant because, after a long series of studies showing that stretching compromises strength and power, it was one of the first to look at endurance performance.

Now the same researchers have published another study, in the current issue of Journal of Strength & Conditioning Research, this time looking at “dynamic” stretching instead of static stretching. Other than the stretching routine, the protocol is exactly the same. The runners spend 15 minutes stretching (or sitting quietly, during the control condition), then run for 30 minutes at 65% VO2max for a running economy measurement, then run as far as they can in the next 30 minutes.

This time, stretching had no significant effect on the distance covered in the time trial: stretchers covered 6.1 +/- 1.3 km, non-stretchers covered 6.3 +/- 1.1 km. On the other hand, the dynamic stretching did increase range of motion in the sit-and-reach test just as much as static stretching (from 32.3 to 37.6 cm). So the basic conclusion: if you’re really into stretching before a run, dynamic stretching will allow you to work on your flexibility without hurting your running performance.

One subtlety, which you pick up if you look at the individual results:

The dynamic warm-up routine takes a fair amount of energy (more details on that below). So you might wonder: for the less fit runners in the group, is it possible that they’re just tired out? The researchers do allude to this possibility:

[I]t is interesting to note that our top 2 performance runners both increased their performance under the dynamic stretching condition with the top runner seeing the largest increase in distance covered in the dynamic stretching condition of 0.2 km. Furthermore, the 2 runners in our study who covered the shortest distance performed better during the nonstretching control condition with the worst performance runner seeing the largest decline in performance after the stretching condition (i.e., 0.6 km). It is possible that elite endurance runners need a warm-up protocol of greater intensity and duration than do recreationally trained runners.

Looking back at the data, it actually looks to me like the top runner was better in the non-stretching condition, but maybe that’s just an artifact of the line thickness they used in the graph. Either way, the differences are pretty small in all cases. To me, the moral of the story is: if you’re an endurance athlete, you may have many reasons for why and how you stretch, but “going faster” shouldn’t be one of them.

As an addendum, here’s the stretching routine the study used:

A total of 10 different movements were used and completed in 15 minutes by performing 2 sets of 4 repetitions of each movement. The dynamic stretching movements were performed in the following order:

(a) Toe and Heel Walks: In these exercises, the subjects walked on their toes for 4 steps followed by walking on their heels for 4 steps to stretch the entire calf complex.

(b) Hip Series: The subjects performed a dynamic stretch of the hip flexors and extensors by placing their hands on a wall with their arms fully extended so that their body was at a 45 angle. In this position, each subject lifted his leg off the ground while bringing the knee to the chest and stepping over a hurdle placed laterally before returning to the starting position.

(c) Hand Walks: The subjects stretched their calves and hamstrings by beginning in a pushup position and walking their feet as close to their hands while keeping their heels flat. As soon as the subjects’ heels came off the ground, they walked with their hands back to a pushup position.

After the hand walks, the subjects performed a series of walking lunges, including (d) rear lunges, (e) lateral lunges, (f ) forward lunges, (g) a knee pull to a lunge, and (h) an ankle pull to a lunge to focus on the quadriceps and gluteus maximus.

(i) Walking Groiners: The subjects began this movement in a pushup position and then brought 1 foot next to the same side hand as to perform a groiner. Instead of holding this position, the subjects walked their hands out to return to the starting position before performing the action on the opposite leg.

(j) Frankensteins: The subjects stood with their feet together and their arms extended straight out in front of them so that their arms were parallel to the ground. While walking, the subjects were instructed to kick 1 leg up to touch the opposite hand to focus on the hamstrings. Every time a step was taken, a kick was made.


21 Replies to “Dynamic stretching doesn’t hurt (or help) running performance”

  1. I find that if I skip dynamic stretches before running (I only do the lunge matrix), I spend the first 3-4 kms having to work out the kinks. It’s a well invested 5 minutes to me, making the run enjoyable from the start.

  2. Good stuff. I always looked at dynamic stretching as a way to warmup and increase flexibility. The fact that the top two performers increased their distance after dynamic stretching I think makes sense since a warmup would benefit them the most due to their higher fitness level.

  3. @Thor: That’s the theory. But there’s very little evidence to back it up:

    The problem with the few studies that appear to show a benefit for pre-exercise stretching is that they fail to distinguish between warming up (i.e. gentle jogging and dynamic exercises that increase the temperature of muscles and thus cause them to become looser) and stretching (trying to extend the maximal range of motion of certain muscles). It’s not clear why the latter should make any difference to injury rates: most running injuries occur well within the normal range of motion, not while the runner is trying to do the splits. Other activities like ballet and playing goal in a hockey game have different constraints, of course!

  4. I don’t get the description of the “hand walk”. Either I completely misunderstand or you must have reversed it somehow? It can’t be possible to keep your heels to the ground while in a pushup position, right?

  5. So I always have issues with studies like this because they don’t reflect what actually happens.

    First, the question needs to be asked if dynamic stretching even matters when running so slow (65%VO2max). Secondly, in terms of performance, does it matter after you’ve spent 30min running already? Seems like the 30min of running is more than enough to “prep” you for a hard finish.

  6. @Steve: For sure, a study like this only really tells us what happens in these particular circumstances for this particular type of runner. But I think there’s some useful info to be gained:

    “First, the question needs to be asked if dynamic stretching even matters when running so slow (65%VO2max). Secondly, in terms of performance, does it matter after you’ve spent 30min running already?”

    Well, when they ran this exact protocol with static stretching, there WERE significant decreases in performance. So if we’re going to advocate dynamic stretching (which, in general, I do), then we need to put it through the same tests we applied to static stretching. This study confirms that, as we hoped/expected, you can do dynamic stretching without significantly hurting your subsequent running performance.

    It would be a mistake to take this study as proof that dynamic stretching never helps performance (and my blog heading is probably a bit misleading there). There have been plenty of studies showing that dynamic stretching can help performance in strength/power tasks. I would expect it to be helpful before, say, racing a mile, where you have to be ready to go hard right from the gun. Probably 5K too, but less so, and with declining importance as you go to longer distances. By the time you get to, say, a half-marathon, I’d guess that the most important role for dynamic drills is just the mental benefit of sticking to a familiar routine.

    In other words, I agree with you that this particular protocol isn’t likely to detect any benefits from any sort of stretching routine. But it can detect harms (as the static study showed), so it’s a useful check.

  7. Back to the injury prevention aspect, I don’t know about running but I thought there were several studies now showing reduction in ACL and other injuries soccer players when following a dynamic warmup program. This goes all the way up to FIFA, with its 11+ program http://f-marc.com/11plus/ To back up your point, it for sure a combination of warmup plus soccer specific movements.

    As a former soccer coach, it drives me absolutely crazy when I see coaches making their kids do static stretching before a game! By now I would think there is no excuse at any level for a coach not knowing that static stretching before exercise is harmful. Even at running races these days, I see very few people doing all the static stretching that was common to see just a few years ago. Personally, before a race I just go through the same dynamic warmup I would for a soccer match since that is what I know. Is it any better than just a pure warmup with some strides? That I cannot say.

  8. @alex

    Yeah, I’ve got no idea about the “hand walk.” I just tried it, and I can’t get my heels flat during any portion of it!

  9. Whether injury prevention or not, static stretching is appropriate is used correctly. If an individual has overactive (tight) muscles that are causing some movement compensations then you use static stretching along with self myofascial release to help correct those compensations and follow up with dynamic movements. Yes, static stretching may decrease performance but when used appropriately (like stated above) you do not get the negative effects associated with it in relation to performance.

  10. I think that there is probably a lot of truth to the researcher’s theory that the fitness of the participants has a big impact on the effects of the warm-up.

    I run group training sessions, and follow a very similar warm-up protocol. Afterwards the fitter individuals are primed and ready to go, whereas some of the less fit individuals will be pretty fatigued already.

    In the context of the training session, this doesn’t really matter as the goal is not performance, but were I getting them ready for a competition I think it would be necessary to have them all do different drills of different durations depending on their individual needs in order to get the best possible performance.

    Studies such as these are important, but I think warm-ups are always going to be one of these areas where a bit of n=1 experimentation is necessary to find out what works best for the individual.

    P.S. I think the “hand walk” is quite possibly the same as an “inch-worm” if that makes things any clearer 😉

  11. Yeah, that hand walk thing must be a mis-print. I can’t imagine anyone being in a pushup position with the heels flat – anatomically impossible.

  12. What always amazed in all the discussion about stretching before workouts / cardio is: why not simply warm up with an activity that mimics the actual activity? For example, swift walking for five minutes before jogging.

  13. @alex
    The handwalk-we use this form of dynamic stretching at ballet. I think it likely means, yes, basically pressup position and then walk the feet forward to meet the hands(effectively jacknifing the body) at this point the hamstrings become so tight that the heels begin to lift off the floor. The heels cant be on the floor right thru walking – you have to move your feet forward and it would be impossible – it is towards the end of the movement when the butt is in the air and the body is bent double that it becomes hard to keep heels pressed down :-)Its a very strong hamstring stretch

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