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Reebok "Springblades"... Would that be Cheating? (Read 207 times)

    I went to the running store today and saw for the first time "Reebok Springblades".

     

     

    I wasn't interested in buying a pair, but doesn't it almost seem like cheating?

     

    ---Not sure if they got the idea after watching Pistorious run in the Olympics or something, but these shoes clearly don't look like any other shoe I have seen to date.

     

    Perhaps a better question might be:  Do these shoes give a runner an advantage of any sort?  And just where do you draw the line between "shoe" and "something else" ?!

     

     

    ---- If we have any Physics majors on the board, I'd love to know if there is anything gained by running on a shoe with "springblades", or if it is a gimmick where more energy is wasted in the compression of the blades than is gained and translated into forward motion.

     

    Any comments?

    The Plan (big parts)→  /// April:  Hampton, VA 24 Hour Run for Cancer  ///   May:  3 Days at the Fair (12 Hour)  ///  Nov:  New York Marathon (Staying at the Waldorf Astoria, its a "Bucket List" thing.  Can someone loan me some Zamunda money to help pay for it?)   ∞

    mab411


    Proboscis Colossus

      I remember seeing them when they were first announced.  All I can think when I see them is, "Oh look, an ankle injury in a shoebox!"

      "God guides us on our journey, but careful with those feet." - David Lee Roth, of all people

        Well, I don't know if there's an advantage or not, but this reminds me of the Spira running shoes that came out a few years ago with springs built in to the heel and forefoot for better "propulsion".  As far as the Springblades though - at $179 they're a fad as far as I'm concerned oops, I forgot, I don't buy many running shoes anymore...

        "I can do 440 in 220"    Half Fanatic #846    "90% of running is half mental"    If I collapse, please pause my Garmin

         

          Well, I don't know if there's an advantage or not, but this reminds me of the Spira running shoes that came out a few years ago with springs built in to the heel and forefoot for better "propulsion".  As far as the Springblades though - at $179 they're a fad as far as I'm concerned oops, I forgot, I don't buy many running shoes anymore...

           

          No you didn't forget, silly goose!

          "If you have the fire, run..." -John Climacus

            I wondered the same thing about them. Without trying them out it's hard to tell how much spring they actually put in your step. Since you push off with your forefoot and that's where the smallest "blades" are, I don't see it helping much at all. To me it looks more like it would just give a cushy landing to heel strikers like many other shoes, with a possible little bounce pushing you onto your forefoot. Most likely you'll just end up with a large dent in your wallet and some rocks in your blades. Must be a pain to clean if you step in mud too.

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            MJ5


            Chief Unicorn Officer

              A gimmick in my opinion. And they're Adidas, not Reebok.

              Mile 5:49 - 5K 19:58 - 10K 43:06 - HM 1:36:54


              Cheap and Evil Girl

                For that kind of money I'd rather have a pair of Hokas.  I would totally try them on though.  Definitely would not purchase.  I don't think they would be be cheating though, reading some reviews online it sounds like they are not actually spring-y.

                I HAVE NO IDEA WHAT I AM DOING.  

                 

                "Mental toughness is built by doing something that is hard over and over again, especially when you don't feel like doing it. Our society has conditioned us to believe that there should be no discomfort, to stop when we are uncomfortable. But the discomfort we feel when we're doing a challenging workout is an important part of the strengthening process." -Jim Afremow, The Champion's Mind: How Great Athletes Think, Train, and Thrive

                  I'm more of a particle/plasma kind of guy, but for what it is worth I don't think it will give you an advantage unless you are over-striding. Everything below is back of the envelope based on my recollection of freshman year so call it approximations, not equalities:

                   

                  High school physics will tell you that F = m*a so a = F/m.

                  Since we live in a 3d world this becomes a(x,y,z) = F(x,y,z)/m.

                   

                  You have one force on landing (where the x component of the force is in the opposite direction of your direction of travel) and then a second force on toe-off when you push yourself forward. So your acceleration with each step becomes:

                   

                  a(x,y,z) = Fi(x,y,z)/m + Ft(x,y,z)

                   

                  We are really only concerned with a(x) because we're runners, not bouncing enthusiasts (or maybe also bouncing enthusiasts) so we'll treat it as:

                   

                  a(x) = Fi(x)/m + Ft(x)

                   

                  Let's now make 2 equations, one for over-striding where Fi(x) is in the opposite direction of Ft(x) and one for a runner who's foot is landing under his center of gravity where Fi(x) and Ft(x) are in the same direction.

                   

                  a(x) = Ft(x) - Fi(x) : over-striding

                  a(x) = Ft(x) + Fi(x) : proper landing

                   

                  The spring compresses during landing and then expands during toe-off. The force needed to compress a spring is F = k*d (where k is the spring constant and d is the distance that the spring is compressed). When the spring expands the force we will pretend that it exerts is F = e*k*d (where, in our simplified example, we use the coefficient e to account for friction so that we can avoid a perpetual motion situation, e < 1).

                   

                  The compressive force will be opposite the direction of impact and the expansion force will be in the direction of toe off. Therefore:

                   

                  a(x) = Ft(x) + e*k*d - (Fi(x) - k*d) : over-striding {where k*d ≤ Fi(x)}

                  a(x) = Ft(x) + e*k*d + Fi(x) - k*d : proper landing

                   

                  My take-away from these equations is:

                   

                  If you are not over-striding the shoes will have no impact on your acceleration if the spring is perfect. Since the spring is not perfect, these shoes will slow you down.

                   

                  If you are over-striding these shoes will lessen the impact force on landing and return some of that force during toe-off. If the spring is perfect this will let you run as though you are not over-striding (but not give you an advantage over someone who is landing properly). Since the spring is not perfect you will never get back all of the force that you put in.

                   

                  You're better off learning not to over-stride than to spend lots of $$$ to buy a shoe that makes it slightly less bad to over-stride.


                  Running Guru

                    I'm more of a particle/plasma kind of guy, but for what it is worth I don't think it will give you an advantage unless you are over-striding. Everything below is back of the envelope based on my recollection of freshman year so call it approximations, not equalities:

                     

                    High school physics will tell you that F = m*a so a = F/m.

                    Since we live in a 3d world this becomes a(x,y,z) = F(x,y,z)/m.

                     

                    You have one force on landing (where the x component of the force is in the opposite direction of your direction of travel) and then a second force on toe-off when you push yourself forward. So your acceleration with each step becomes:

                     

                    a(x,y,z) = Fi(x,y,z)/m + Ft(x,y,z)

                     

                    We are really only concerned with a(x) because we're runners, not bouncing enthusiasts (or maybe also bouncing enthusiasts) so we'll treat it as:

                     

                    a(x) = Fi(x)/m + Ft(x)

                     

                    Let's now make 2 equations, one for over-striding where Fi(x) is in the opposite direction of Ft(x) and one for a runner who's foot is landing under his center of gravity where Fi(x) and Ft(x) are in the same direction.

                     

                    a(x) = Ft(x) - Fi(x) : over-striding

                    a(x) = Ft(x) + Fi(x) : proper landing

                     

                    The spring compresses during landing and then expands during toe-off. The force needed to compress a spring is F = k*d (where k is the spring constant and d is the distance that the spring is compressed). When the spring expands the force we will pretend that it exerts is F = e*k*d (where, in our simplified example, we use the coefficient e to account for friction so that we can avoid a perpetual motion situation, e < 1).

                     

                    The compressive force will be opposite the direction of impact and the expansion force will be in the direction of toe off. Therefore:

                     

                    a(x) = Ft(x) + e*k*d - (Fi(x) - k*d) : over-striding {where k*d ≤ Fi(x)}

                    a(x) = Ft(x) + e*k*d + Fi(x) - k*d : proper landing

                     

                    My take-away from these equations is:

                     

                    If you are not over-striding the shoes will have no impact on your acceleration if the spring is perfect. Since the spring is not perfect, these shoes will slow you down.

                     

                    If you are over-striding these shoes will lessen the impact force on landing and return some of that force during toe-off. If the spring is perfect this will let you run as though you are not over-striding (but not give you an advantage over someone who is landing properly). Since the spring is not perfect you will never get back all of the force that you put in.

                     

                    You're better off learning not to over-stride than to spend lots of $$$ to buy a shoe that makes it slightly less bad to over-stride.

                     

                    Wow dude, that's a pretty hardcore argument you have there, but I like it. I'm glad science can back up how ugly these shoes are!

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                    The Running Father

                     

                    PR's - 5K - 20:47 (2013) | 10K - 45:23 (2013)  | 13.1 - 1:53:44 (2013)  | 26.2 - N/A

                     

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                      At $140, they're not more than other shoes, but not sure those would help me on my muddy trail.

                       

                      These might be fun:

                      https://www.youtube.com/watch?v=MutvUfQcmMg

                         Wow dude, that's a pretty hardcore argument you have there, but I like it. I'm glad science can back up how ugly these shoes are!

                         

                        Thanks, I agree they are super ugly. By the way, I ignored the fact that the spring idea could in theory transfer some F(y) into F(x) because it could as easily go the other way so I treated it as a wash.


                        CUCHSUX

                          whoa, are you kidding me?..those are freaking cool! i must have those shoes! and...cheating? wearing a wetsuit is cheating.

                           

                          i refuse to strap a belt on and water run so whatever it takes man...whatever it takes.

                          the worst thing you can do for someone drowning in shark infested waters is throw them a life preserver. don't you think?

                           

                           

                           

                           


                          MoBramExam

                            If you see any runner wearing those at a local race, they are probably going to finish about the same time as the 260lb guy with two knee braces and the OA walk winner.

                             



                            ShuffleFaster


                               

                              Thanks, I agree they are super ugly. By the way, I ignored the fact that the spring idea could in theory transfer some F(y) into F(x) because it could as easily go the other way so I treated it as a wash.

                               

                              Thanks for the analysis--fun to read!

                               

                              Question, though--does your argument about overstriders make the assumption that the overstrider is landing on the spring exactly dead on (i.e., in the axis of the spring)?   Since many people who heel strike tend to land on the outside of the heel and then pronate inward, wouldn't some of the theoretical spring return be mitigated by the natural stride of these folks, since the expansion force vector would not necessarily be in the forward direction?

                               

                              It just seems like it would be hard to predict who, if anyone, these would make go faster.

                              spinach


                                I got a bunch of ads from Adidas for these shoes this summer.  I looked at the specs and they seem to be awful heavy 13 oz.  That is almost twice as much as my normal running shoes are.  I'll pass on them.

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