I have been wondering about the role of flexibility in distance running, but as far as I know there are no good studies on it. There is some evidence that suggests that good runners are less flexible than not so good ones, but it really does not say much. I've given the matter some thought and decided that a good step towards understanding the role of flexibility will be to look at a large enough sample of guys that run 800 under 2:00 and 5000 under 15:00 and have them do some simple range of motion tests. My reasoning - 800 meter speed can be achieved with power to a great extent, and 5000 meter speed through aerobic capacity to a great extent as well. So you need to set the bar high enough so that raw power or raw aerobic capacity without some extra support from somewhere else in most cases will not be good enough. Thus the above performance cut offs. So I want to get a feel as to what extent that something extra is in the flexibility in the particular ranges of motion if it is there at all. I am not a professional researcher and do not have either the time or the resources to conduct a formal study. But I still would like to do something, and this is the best I can do.
I would appreciate responses from everyone, but particularly from those who are currently capable of running 800 under 2:00 and 5000 under 15:00. Please answer the following questions:
1. Your life-time PRs, and your estimated (or better actual) fitness level at this time in distances 800 through the marathon as applicable.
2. Sit on the floor with your legs straight. Keeping your legs straight, can you reach your toes with your hands? If not, how close did you get?
3. Sit on the floor. Bring your feet together about half of the leg length towards your point of support. Hold your feet together with your knees bent and spread your legs sideways as far as they can go. Can your knees touch the floor? If not, how close did you get?
4. Sit on the floor leaning against a wall. Take your foot with your hands and try to bring it behind your head. Can you touch the back of your head with your heel? If not, how far did it go?
5. Stand up with legs at shoulder width. Keep your legs straight and try to touch your knees with your forehead. If you cannot, how close did you get?
If you have other suggestions for the important ranges of motion tests, feel free to share.
I think it's been generally found these days that muscle tension is crucial to getting adequate power in every step. Static stretching can sometimes diminish the release of power in the muscles. But elasticity is important to avoiding injury and handling the impact better. You want a balance of both that is event-specific.
Also, I think your questions would have vastly different results for women than for men. Women are generally more flexible, but I wouldn't go and make an argument for flexibility hurting running ability just based on that finding.
I have read those studies and understand the above, but it is too general. What I have not seen is something like this: we took N guys that were fast, and they were so fast that there is no way they could have been this fast just because they run 100 miles a week and are aerobic animals, so they had something else. We measured their ranges of motion, and we found this. Then we took N guys that were 30 or even 60 seconds per mile slower than them on every distance, even though they trained the same. We measured their ranges of motion and we found this. If you are aware of any such studies, please post a link or some other reference.
Intuitively, if you look at a pack that is running 14:00 in the 5000, then 15:00, 16:00, and 17:00, you will find a general digression of the smoothness and fluidity of the stride as the ability of the runner decreases. In the 17:00 pack you will find the most runners that look like they are working against themselves, while the 14:00 pack compared to them will look like a herd of antelopes. But those are the visual perceptions. I would like to get a more detailed understanding of that smoothness or the lack of it. Obviously the "antelope" runner has a certain freedom of movement that is not available to the "elephant" runner. Here are the questions I am trying to answer:
- Can that freedom of movement be explained merely by having a certain level of flexibility in particular ranges of motion, or possibly by some balance of those that is easy to identify?
- Can you train the "elephant" runner to progress at least half-way to the level of the "antelope" by working on flexibility with particular targets in mind?
- If yes, what ranges of motion are important?
- If it is not flexibility, then what is it and how do we improve it?