Flexibility and running economy

[Ryan]

I think I remember a study from about 10 years ago that said the same thing but, if that's the case, here we go again. There are reasons to be skeptical about the results (for example, 8 participants - 4 men, 4 women is hardly a large survey and could create skewed results) but here it goes.

The significant relationship demonstrates that the less flexible distance runners tended to be more economical, possibly as a result of the energy-efficient function of the elastic components in the muscles and tendons during the stretch-shortening cycle.

PubMed abstract

Of course, I learned from experience that, at some point, less flexibility can become a problem when the elastic gets stretched a bit too tight.

[GTF]

Years ago, when he was still competing at a high level, Mark Plaatjes consulted with local exercise physiology guru Andy Pruitt regarding some sort of tightness or injury.  Pruitt questioned him about his notable lack of flexibility and Plaatjes said that it was intentional, that the tension created was desired -- just like a tight spring, tight muscles are more explosive.  That was just Plaatjes's view at that time, though.  Pruitt related this at a stretching clinic to illustrate that there are varying views on the subject, though Pruitt's overall message was that stretching is good. 

The level of useful flexibility would vary based on one's event.  Sprinters, while needing to maintain explosiveness, need to be flexible enough to get extension to take full advantage of that explosiveness.  As a rule, milers have longer and more explosive strides than marathoners do.  Look at the stride of Alberto Salazar or the Japanese marathoners, it is a shuffle that appears compact to the point of restrictive.  How flexible a runner ends up being would seem to be determined largely by how they train.  Running 200m repeats at mile race pace, and the stride that requires, would likely do more to effect the appropriate level of flexibility than stretching for ten minutes prior to the workout would.  A strong core also plays a role in level of flexibility.

The stretching I do is not necessarily to effect increased flexibility but for better recovery.  During exercise, the muscles contract around the blood vessels and stretching helps to pull the muscle so that the vessels are less restricted and wider vessels means nutrients can be carried to and waste products can be carried away from muscles at a greater rate, improving muscle repair rates.  The stretching follows the form of going to the point of resistance, to take the muscle back to its original shape and not to overstretch and further damage muscle.

[Double]

I dislike stretching therefore I don't do it.  If I have an issue on the rise, I will give it attention until it passes.  Based on that alone I see the value.  I don't have a theory or stance on stretching, but one would be hard pressed to convince me it is worthless.  Who pulls a muscle starting out on a routine jaunt?

[GTF]

Scott Simmons, one of the brightest coaches in the US and one who keeps abreast of the science, made me realize the utility stretching can have for recovery.  I do not do a very extensive routine and I can tell the difference if I have skipped it for more than one run.

[Ryan]

GTF, I do think there is a point to that. We have to maintain some flexibility in order to fluidly move through the range of motion required for our training and racing. Any flexibility beyond that is probably unnecessary and, according to this study, possibly counterproductive.

As for post-run stretching, I've found the same thing as you. I have a routine, though I wouldn't call it anything more than what I found works through trial and error. Honestly, I don't hold the stretches long enough for what they say should help. I do think it helps me some with retaining a necessary range of motion but, beyond that, I simply know that I feel better the next run if I stretch.

[r-at-work]

  The stretching follows the form of going to the point of resistance, to take the muscle back to its original shape and not to overstretch and further damage muscle.

this is how my massage therapist explained the stretching she suggested I do... her theory is that since I'm not mechanically perfect, running tightens up some muscles more than others and tends to throw off my stride and the compensation excalates what might be progress towards an injury... so I have a short set of stetches that try to undo the tight muscles... I also have a set of strengthening exercises to try and build up some muscle to balance out my running muscles...

how do I know this works... just like everyone else, it's anecdotal, when I do both I have fewer injuries/set backs...
-Rita

[GTF]

More on stretching and mobility (as opposed to flexibility):
http://masterstrack.com/blog/002983.html

[r-at-work]

thanks GTF, that's the kind of stuff I've been trying to incorporate in my training... no stretching cold muscles before running, starting out with a mile or so REALLY easy jog before picking it up or starting track work outs... I do sets of yoga-like stretches & some core work every evening and small free weights every other evening... helps to relax me, loosen up whatever muscles got tight during the day and serves as an inventory of what I might need to keep an eye on the next day...

it's great to get 'proof' for what has seemed to work for me!

-Rita

[GTF]

Right, it is good to get confirmation that what one is doing is not just some eccentric tangent, that there is a sound basis for it.  On the same token, I am continually looking to challenge my regimen and refine what I do, provided a sound basis for doing so.  This past summer, when I started up hard workouts again, I started to get away from the typical pre-workout (post-warmup) stretching.  I had still clung to a couple of dynamic (leg swing) stretches, however.  Going forward, I will not even do those and just save all the stretching for after the running is done.  No more pre-race stretching, either.