Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

How to run 50% faster without external energy (2020)

science.org

Post reply on HN
Print view View original

31–40 of 206 posts

Re: How to run 50% faster without external energy (2020)

#31

Post by tech_ken »

ITT: people who read scientific articles by skimming the pictures.

The proposal isn't "springs under your feet" it's "springs along your legs that you load while your leg is in the air". The point is that by loading the spring with a leg which is otherwise not doing anything you're able to increase the overall energy output of the body. Their Fig. 2 shows exactly the (theoretical) difference between the naive "jumping stilts" approach and what they're suggesting.

> Cycling is faster than running partly because (i) the rolling motion of the wheels prevents collisional energy losses from stepping but also because (ii) wheels can support the weight of the body in place of the legs, while (iii) pedals enable the human to supply energy continuously in the air instead of intermittently when the leg is on the ground .

Super interesting to see that they still can't outperform cycling. Presumably their proposal resolves most or all of point (iii), so the difference is from (i-ii). I would assume that, of these, (ii) would be the hardest to replace with any kind of leg attachment

Re: How to run 50% faster without external energy (2020)

#34

Post by WestCoastJustin »

rotskoff wrote: post #29
tiffanyh wrote: post #20

Nike Vaporfly. I'm surprised it wasn't mentioned that 2 recording breaking marathon runs were by athletes wearing the Nike Vaporfly shoe. The shoe was ultimately banned due to the giving too much "bounce" (free energy) to the runners. https://www.reuters.com/article/us-athletics-shoe/nike-proto...

In fact, the shoe was not banned and it is one of the most widely used marathon racing shoes out there. Nearly all other running shoe companies followed suit and made more efficient racing flats with carbon plates and high energy return foams. Some restrictions did come out, including limits on the "stack height" racing shoes and more stringent restrictions on the track. The current generation of these, the alphafly…

Looks like initially was then wasn't re: https://en.wikipedia.org/wiki/Nike_Vaporfly_and_Tokyo_2020_O...

Re: How to run 50% faster without external energy (2020)

#35

Post by oezi »

renewiltord wrote: post #15

I considered using jumping stilts to run to work rather than skating or cycling. However, the skill level required to master them sufficiently to run required more training than I was willing to put in. I eventually ended up buying some shift.io moonwalkers, which do have quite a speed-up effect. The problem is that they're quite heavy and the walking motion required to use them effectively ended up requiring my ante…

What are you trying to achieve? Keep weight/volume of the device low?

Or is about training running but being bicycle-fast?

Re: How to run 50% faster without external energy (2020)

#36

Post by mikestew »

tiffanyh wrote: post #20

Nike Vaporfly. I'm surprised it wasn't mentioned that 2 recording breaking marathon runs were by athletes wearing the Nike Vaporfly shoe. The shoe was ultimately banned due to the giving too much "bounce" (free energy) to the runners. https://www.reuters.com/article/us-athletics-shoe/nike-proto...

Mmmm, not quite. The ones you and I can buy have a single plate, and stack height of 36mm. The ban was for shoes (like the VaporFly prototype) with >40mm stack height and/or multiple plates. Not that this article clears the matter a whole lot, but there is more information (sorry, couldn't find a succinct article on the topic): https://www.cbsnews.com/news/nike-vaporfly-running-sneaker-n...

I've used them (as a ~3:00 marathoner). They probably are good for a few minutes off your time. But what I noticed most was that the next day I said to my wife, "I don't think I ran hard enough." Oh, I ran hard enough, but the shoes do so much better at keeping the legs from getting trashed. Normally, I'd take the day off the day after a marathon. Instead, I said, "screw it, I'm going for a short run."

And the VaporFly has little to do with this proposition, other than using a spring-like device.

Re: How to run 50% faster without external energy (2020)

#37

Post by hinkley »

tech_ken wrote: post #31

ITT: people who read scientific articles by skimming the pictures. The proposal isn't "springs under your feet" it's "springs along your legs that you load while your leg is in the air". The point is that by loading the spring with a leg which is otherwise not doing anything you're able to increase the overall energy output of the body. Their Fig. 2 shows exactly the (theoretical) difference between the naive "jumpin…

One of the reason pro cyclists clip their feet to their pedals is so they can load the “other” leg through the back of the stroke, and across the bottom as well by pulling back on the loaded leg. Come unclipped in a sprint and you’re fucked.

Sounds like this is the same thing for running.

Re: How to run 50% faster without external energy (2020)

#39

Post by seattleman »

tiffanyh wrote: post #20

Nike Vaporfly. I'm surprised it wasn't mentioned that 2 recording breaking marathon runs were by athletes wearing the Nike Vaporfly shoe. The shoe was ultimately banned due to the giving too much "bounce" (free energy) to the runners. https://www.reuters.com/article/us-athletics-shoe/nike-proto...

The specific version of the Nike Alphafly shoe that Eliud Kipchoge wore for his sub 2 hour marathon (out of competition) was banned, but subsequent versions of the Alphafly and Vaporfly are legal and still being used to break records today. As a result of Kipchoge's sub-2 marathon run, some rules were set on shoe design, namely:

1. Max stack height of 40 mm 2. Only one carbon plate allowed per show (Kipchoge's had 3)

Re: How to run 50% faster without external energy (2020)

#40

Post by oezi »

tech_ken wrote: post #31

ITT: people who read scientific articles by skimming the pictures. The proposal isn't "springs under your feet" it's "springs along your legs that you load while your leg is in the air". The point is that by loading the spring with a leg which is otherwise not doing anything you're able to increase the overall energy output of the body. Their Fig. 2 shows exactly the (theoretical) difference between the naive "jumpin…

It is a bit sad that the article doesn't explain what the motion would feel like similar to. Would it be like walking stairs?
Post reply on HN