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Efficient Running (Read 280 times)

pedaling fool


    I saw this article about minimalist shoes and was curious about one part of it. BTW, not asking about this with respect to injuries, just the efficiency.

     

    Here's an excerpt of what caught my eye:  http://well.blogs.nytimes.com/2013/06/05/is-barefoot-style-running-best-new-studies-cast-doubt/

     

    "Then, in a separate experiment, they asked each runner to switch styles — the heel-strikers were to land near the balls of their feet and the forefoot strikers with their heels — while the researchers gathered the same data as before.

     

    In the end, this data showed that heel-striking was the more physiologically economical running form, by a considerable margin. Heel strikers used less oxygen to run at the same pace as forefoot strikers, and many of the forefoot strikers used less oxygen — meaning they were more economical — when they switched form to land first with their heels.

     

    Most of the runners also burned fewer carbohydrates as a percentage of their energy expenditure when they struck first with their heels. Their bodies turned to fats and other fuel sources, “sparing” the more limited stores of carbohydrates, says Allison Gruber, a postdoctoral fellow at the University of Massachusetts Amherst, who led the study. Because depleting carbohydrates results in “hitting the wall,” or abruptly sagging with fatigue, “these results tell us that people will hit the wall faster if they are running with a forefoot pattern versus a rear-foot pattern,” Dr. Gruber says."

     

    How can that be? If you are striking your heel doesn't that mean that your foot is going out in front of you and when it strikes the ground it naturally has a breaking effect?

      I think it takes considerable time to develop the most efficient stride.  Form, muscles, posture, bearing, and motion gradually develop over months and years.  This:

       

      they asked each runner to switch styles

       

      is guaranteed to put a runner into a less efficient stride, whether toward or away from heel strike, or any other immediate change in their posture.

      Well at least someone here is making relevance to the subject.


      barefootin'

        but the experiment indicated that heel-striking was more efficient for both habitual forefoot strikers and heel-strikers

        Bill Wagnon / stl

        zonykel


           

          How can that be? If you are striking your heel doesn't that mean that your foot is going out in front of you and when it strikes the ground it naturally has a breaking effect?

          I think you are equating heel striking with over striding.

           

          Jay Dicharry has an interesting chapter on running gait in his book "anatomy for runners". Here is a short excerpt:

           

          "The main energy source we use when running comes from the storing and releasing of elastic energy. If we have good storage and release of energy then our muscles don't have to work as hard. If we store too much or can't release properly (two of the most common problems in runners), our muscles have to do more work to keep you running along.

           

          When running at a steady speed, your foot contacts the ground in front of the body, so from the point of foot contact until the foot is directly under the center of mass, you are in an energy absorption phase. Most folks call this the braking phase. Even though this is totally accurate, we are avoiding this terminology right now because runners get bothered by the idea that they might be braking when they are running. In fact, some of these proprietary running styles have told runners that they should minimize braking at all costs and land directly "under their body". While minimizing braking forces sounds nice, it's not exactly true. To run faster you actually need to store energy in the loading phase so you can release it later.

           

          Unless you are accelerating, your foot always lands in front of your center of mass, and in fact this is a very good thing. The whole point of landing in front of your body is to store elastic energy."

          pedaling fool


            I think you are equating heel striking with over striding.

             

            Yes, I guess I am equtating heel striking with over striding. If those researchers asked me to strike my heel while running I don't know how else I could strike it, other than overstriding. Unless I flexed my foot unnaturally as I landed, but that would take a lot of concentration and probably mess up my running, thus make it less efficient.

             

            I watched this video and they didn't really talk about heel strikes, but you could see most were landing on their midfoot, regardless if they were Gliders or Gazelles. So I'm not seeing how landing on their heel would help?  http://www.youtube.com/watch?v=tJWPwVF30yo

              Midfoot strike is generally best.

                 

                  Birds suck.

                  Runners run.


                  Feeling the growl again

                    "If you want to be a bad a$s, then do what a bad a$s does.  There's your pep talk for today.  Go Run." -- Slo_Hand

                     

                    pedaling fool


                      Yes, I guess I am equtating heel striking with over striding. If those researchers asked me to strike my heel while running I don't know how else I could strike it, other than overstriding. Unless I flexed my foot unnaturally as I landed, but that would take a lot of concentration and probably mess up my running, thus make it less efficient.

                       

                      I watched this video and they didn't really talk about heel strikes, but you could see most were landing on their midfoot, regardless if they were Gliders or Gazelles. So I'm not seeing how landing on their heel would help?  http://www.youtube.com/watch?v=tJWPwVF30yo

                       

                      Here are two more videos (much shorter) that show non-heel strikes  http://www.youtube.com/watch?v=hsUfo_jHQ60   &   http://www.youtube.com/watch?v=mTMgIViinuQ

                       

                       

                      I'm starting to wonder if that "study" wasn't financed by some big time shoe company.

                       

                      BTW, I'm not interested in shoe wear for runners, not interested in the minimalist arguement; I'm just curious why they claim heelstriking is more efficent, but maybe it's a misunderstanding of sorts, since I DO associate heel strikes with overstriding. I know there are people that naturally heel strike without overstriding, but the study seems to insinuate that virtually everyone should heel strike. I'm confused on what they're saying in my attached excerpt in the OP.

                        My wife says i have a short attention spanners are great, aren't they?

                        pedaling fool


                          I think you are equating heel striking with over striding.

                           

                          Jay Dicharry has an interesting chapter on running gait in his book "anatomy for runners". Here is a short excerpt:

                           

                          "The main energy source we use when running comes from the storing and releasing of elastic energy. If we have good storage and release of energy then our muscles don't have to work as hard. If we store too much or can't release properly (two of the most common problems in runners), our muscles have to do more work to keep you running along.

                           

                          When running at a steady speed, your foot contacts the ground in front of the body, so from the point of foot contact until the foot is directly under the center of mass, you are in an energy absorption phase. Most folks call this the braking phase. Even though this is totally accurate, we are avoiding this terminology right now because runners get bothered by the idea that they might be braking when they are running. In fact, some of these proprietary running styles have told runners that they should minimize braking at all costs and land directly "under their body". While minimizing braking forces sounds nice, it's not exactly true. To run faster you actually need to store energy in the loading phase so you can release it later.

                           

                          Unless you are accelerating, your foot always lands in front of your center of mass, and in fact this is a very good thing. The whole point of landing in front of your body is to store elastic energy."

                          BTW, as I continue to watch the videos that I linked in other posts I start to wonder exactly what does Jay Dicharry mean by: "When running at a steady speed, your foot contacts the ground in front of the body..."

                           

                          Just how far in front on one's center mass? If you look at the videos those runners are not putting their foot too far out there.

                            Well at least someone here is making relevance to the subject.

                              My wife says i have a short attention spanners are great, aren't they?

                              zonykel


                                http://www.runblogger.com/2013/05/is-heel-striking-evil-more-evidence.html

                                 

                                Above is a link to a recent blog on the different types of heel strike.

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