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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 whi

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

hinkley 3y ago
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.
- criddell 3y ago
  Have you ever used an elliptical chainring?
  - jph 3y ago
    Yes, elliptical chainrings are great IMHO, especially if you train for elliptical continual exertion. Added 2km to my speed.
    - jackmott42 3y ago
      No it did not.
      - bee_rider 3y ago
        It is hard to say if it is implausible without the time unit. 2km/day? I believe it. 2km/s? Seems unlikely.
        jph 3y ago
        Ha! Yes you're right, units matter. For me it was 2 km/hour, on rides for an hour or so typically above 20 km/hour, on a hybrid bike, on long streets in Marin. The ellipticals worked especially well, for me, in combination with bar ends.
      - hinkley 3y ago
        It's not that far above what some people were claiming when they were new. There were people claiming 1mph improvement. I was... skeptical. Placebo effect? Who knows. I don't think I ever got around to trying one. I was the youngest regular member of our club. Power output was not my primary problem.
- rottencupcakes 3y ago
  The idea that your muscles have enough strength on the upstroke to contribute meaningfully to cycling is actually a bit of a misunderstanding. Your leg muscles for lifting are much much much weaker than your leg muscles for pushing - they're designed to only lift up the weight of your leg and not much more. The main advantage of the clips is to keep your leg in contact with the pedal throughout the cycle and make sure the ball of your foot is optimally placed on the pedal. With a traditional pedal you have to keep some downward force on the pedal to create friction to avoid slipping off, so even when that leg is rising up, you can't completely unload the pedal. With clips you can completely unload the pedal.
  - onetimeuse92304 3y ago
    Any muscle is trainable. To some extent. If you cycle enough, you will develop muscles necessary to pull the pedal up. Additionally, the goal isn't to double your power output. It is to be better than the other cyclist. Even by just a tiny bit. I personally think that clipping the feet helps more with left right stability. Also, if you are pulling with one leg, you can potentially push more with the other. Normally you can only push as much as you weight, but with the other leg clipped you can push your weight plus the force you use to pull the other pedal.
    - justsocrateasin 3y ago
      This is true for certain metabolic zones but not others. If you're sprinting then yes, you get a higher power output while pulling up on the pedal. However if you're going for any kind of endurance (longer than a minute) the limiting factor is not muscular but cardiovascular/aerobic, and using less efficient muscles (the ones used for pulling up) will actually hinder your performance since you'll need to be supplying those with oxygen, thus decreasing total cycling economy.
      - onetimeuse92304 3y ago
        I am not versed with cycling economy. But yeah, it makes sense. On a bike, if you want to put up more power you have options to push harder or spin faster. If you had to push harder than your weight, you could always change your gears to rather spin faster.
- Someone 3y ago
  > Come unclipped in a sprint and you’re fucked. Not necessarily :-) See https://www.eurosport.com/cycling/famenne-ardenne-classic/2023/arnaud-de-lie-somehow-wins-famenne-ardenne-classic-despite-pedalling-to-the-line-on-one-leg_vid2002392/video.shtml https://www.eurosport.com/cycling/famenne-ardenne-classic/20... for an example where that happened and the sprinter still won.
  - hinkley 3y ago
    Jesus. Well momentum can be your friend or your enemy. It looks like not only did he pull his foot out, he also clipped his chain or front derailleur with his foot and popped himself down into the small chainring.
- pharmakom 3y ago
  I believe this was disproven actually. The real reason is security under heavy power output.
  - hinkley 3y ago
    I’m looking at these experiments and I am dubious. How do you explain the effect in OP’s device if this is “disproven”? Nobody seems to have offered an alternative theory.
- jackmott42 3y ago
  This is false, even cyclists who think they pull up and pull back do not, and it is less efficient to do so. However it is a VERY common misconception that you should do this.
  - hinkley 3y ago
    When the only American who won the Tour de France without drugs tells people to do something, a lot of people are going to do it. Anyway, I can't find any of these so-called studies that admits to knowing what a sprinter is let alone a green jersey, so I'm going to keep my eye out for less flawed studies. In fact, get me one by a team medic or physiologist, and then we can talk. Until then it's nerds in coats coatsplaining things to people actually doing the work.
- andy99 3y ago
  I'm not disagreeing with the above comments though I am curious about the factor of how much energy output a person is actually capable of. Running isn't leisurely and you can reach (as far as I know) maximum physical (cardiac?) output running. My point being it's not like there is unused capacity to work harder when you're running that's making you slower. So there must be more to it than just doing more at times you'd otherwise be idle.
oezi 3y ago
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?
- tech_ken 3y ago
  I don't think they have a functional prototype, so probably difficult to predict a qualitative comparison to other types of motion. Honestly my guess is that it's not directly comparable to anything else really, because you typically don't have to output energy during the "off-phase" of walking. Maybe like having a rubber band around the bottom of your foot which you're also holding in your hand?
- ramses0 3y ago
  In the "clipped to cycling pedals" example, the description I was recommended to aim for was "rolling a log in a circle" as opposed to pushing/pulling. It makes a big difference to be able to have both legs "inputting" energy into the system at the same time. I would say "non-linear response" but that's probably inaccurate... but maybe not? Basically once you've overcome rolling resistance to _start_ going up a hill, being able to continue it with "both legs" instead of one feels like you're not overcoming the "zero-to-one" hurdle as much and instead staying in the "one-to-two" zone. Like you're not "starting over" every downstroke, but instead transitioning your power from one leg to the other. Given a pretty basic commuter bike that I'd upgraded over time, it felt like moving from ~35 to ~20 tires (basic to "road bike") felt like "gaining a gear" (what used to need 1st gear, I could now do in 2nd), and same with clips, also "gaining a gear" (cumulative: now I could be in 3rd instead of being in 1st).
scythe 3y ago
The next question, following this framework, is that in order for a suspended leg to load a spring, it will be necessary to apply a force against some other part of the body -- so where does it go? On a bicycle this is the other foot, which is made possible by the pedals. But with a spring affixed to the leg, the most likely result is a force against the dorsal surface of the thigh -- not exactly a pleasant idea (try pushing two fingers into the back of your leg if you're curious). So then you are inventing something of an exoskeleton to manage this. Cycling is extremely efficient -- around 80% of the energy expended by the body is converted to forward motion, even in the simplest configuration, and this can be enhanced further under some circumstances.
make3 3y ago
yeah also bike speeds keeps mechanical difficulty optimal, vs having to move your legs very fast at minimal difficulty
Ericson2314 3y ago
Reverse running, that sure sounds like a lot of tripping and falling! The power leg and the stability/control leg being opposite not the same really boggles my mind.
- Ericson2314 3y ago
  If we're getting really transhuman with this, assuming the brain is more malleable than the leg, I think it would actually be easier physiologically to run backwards than forwards with this. Real shape rotators will know what I mean ;)
deleted 3y ago
[deleted]

hinkley 3y ago

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.

criddell 3y ago
Have you ever used an elliptical chainring?
- jph 3y ago
  Yes, elliptical chainrings are great IMHO, especially if you train for elliptical continual exertion. Added 2km to my speed.
  - jackmott42 3y ago
    No it did not.
    - bee_rider 3y ago
      It is hard to say if it is implausible without the time unit. 2km/day? I believe it. 2km/s? Seems unlikely.
      - jph 3y ago
        Ha! Yes you're right, units matter. For me it was 2 km/hour, on rides for an hour or so typically above 20 km/hour, on a hybrid bike, on long streets in Marin. The ellipticals worked especially well, for me, in combination with bar ends.
    - hinkley 3y ago
      It's not that far above what some people were claiming when they were new. There were people claiming 1mph improvement. I was... skeptical. Placebo effect? Who knows. I don't think I ever got around to trying one. I was the youngest regular member of our club. Power output was not my primary problem.
rottencupcakes 3y ago
The idea that your muscles have enough strength on the upstroke to contribute meaningfully to cycling is actually a bit of a misunderstanding. Your leg muscles for lifting are much much much weaker than your leg muscles for pushing - they're designed to only lift up the weight of your leg and not much more. The main advantage of the clips is to keep your leg in contact with the pedal throughout the cycle and make sure the ball of your foot is optimally placed on the pedal. With a traditional pedal you have to keep some downward force on the pedal to create friction to avoid slipping off, so even when that leg is rising up, you can't completely unload the pedal. With clips you can completely unload the pedal.
- onetimeuse92304 3y ago
  Any muscle is trainable. To some extent. If you cycle enough, you will develop muscles necessary to pull the pedal up. Additionally, the goal isn't to double your power output. It is to be better than the other cyclist. Even by just a tiny bit. I personally think that clipping the feet helps more with left right stability. Also, if you are pulling with one leg, you can potentially push more with the other. Normally you can only push as much as you weight, but with the other leg clipped you can push your weight plus the force you use to pull the other pedal.
  - justsocrateasin 3y ago
    This is true for certain metabolic zones but not others. If you're sprinting then yes, you get a higher power output while pulling up on the pedal. However if you're going for any kind of endurance (longer than a minute) the limiting factor is not muscular but cardiovascular/aerobic, and using less efficient muscles (the ones used for pulling up) will actually hinder your performance since you'll need to be supplying those with oxygen, thus decreasing total cycling economy.
    - onetimeuse92304 3y ago
      I am not versed with cycling economy. But yeah, it makes sense. On a bike, if you want to put up more power you have options to push harder or spin faster. If you had to push harder than your weight, you could always change your gears to rather spin faster.
Someone 3y ago
> Come unclipped in a sprint and you’re fucked. Not necessarily :-) See https://www.eurosport.com/cycling/famenne-ardenne-classic/2023/arnaud-de-lie-somehow-wins-famenne-ardenne-classic-despite-pedalling-to-the-line-on-one-leg_vid2002392/video.shtml https://www.eurosport.com/cycling/famenne-ardenne-classic/20... for an example where that happened and the sprinter still won.
- hinkley 3y ago
  Jesus. Well momentum can be your friend or your enemy. It looks like not only did he pull his foot out, he also clipped his chain or front derailleur with his foot and popped himself down into the small chainring.
pharmakom 3y ago
I believe this was disproven actually. The real reason is security under heavy power output.
- hinkley 3y ago
  I’m looking at these experiments and I am dubious. How do you explain the effect in OP’s device if this is “disproven”? Nobody seems to have offered an alternative theory.
jackmott42 3y ago
This is false, even cyclists who think they pull up and pull back do not, and it is less efficient to do so. However it is a VERY common misconception that you should do this.
- hinkley 3y ago
  When the only American who won the Tour de France without drugs tells people to do something, a lot of people are going to do it. Anyway, I can't find any of these so-called studies that admits to knowing what a sprinter is let alone a green jersey, so I'm going to keep my eye out for less flawed studies. In fact, get me one by a team medic or physiologist, and then we can talk. Until then it's nerds in coats coatsplaining things to people actually doing the work.
andy99 3y ago
I'm not disagreeing with the above comments though I am curious about the factor of how much energy output a person is actually capable of. Running isn't leisurely and you can reach (as far as I know) maximum physical (cardiac?) output running. My point being it's not like there is unused capacity to work harder when you're running that's making you slower. So there must be more to it than just doing more at times you'd otherwise be idle.

oezi 3y ago

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?

tech_ken 3y ago
I don't think they have a functional prototype, so probably difficult to predict a qualitative comparison to other types of motion. Honestly my guess is that it's not directly comparable to anything else really, because you typically don't have to output energy during the "off-phase" of walking. Maybe like having a rubber band around the bottom of your foot which you're also holding in your hand?
ramses0 3y ago
In the "clipped to cycling pedals" example, the description I was recommended to aim for was "rolling a log in a circle" as opposed to pushing/pulling. It makes a big difference to be able to have both legs "inputting" energy into the system at the same time. I would say "non-linear response" but that's probably inaccurate... but maybe not? Basically once you've overcome rolling resistance to _start_ going up a hill, being able to continue it with "both legs" instead of one feels like you're not overcoming the "zero-to-one" hurdle as much and instead staying in the "one-to-two" zone. Like you're not "starting over" every downstroke, but instead transitioning your power from one leg to the other. Given a pretty basic commuter bike that I'd upgraded over time, it felt like moving from ~35 to ~20 tires (basic to "road bike") felt like "gaining a gear" (what used to need 1st gear, I could now do in 2nd), and same with clips, also "gaining a gear" (cumulative: now I could be in 3rd instead of being in 1st).

scythe 3y ago

The next question, following this framework, is that in order for a suspended leg to load a spring, it will be necessary to apply a force against some other part of the body -- so where does it go? On a bicycle this is the other foot, which is made possible by the pedals. But with a spring affixed to the leg, the most likely result is a force against the dorsal surface of the thigh -- not exactly a pleasant idea (try pushing two fingers into the back of your leg if you're curious). So then you are inventing something of an exoskeleton to manage this. Cycling is extremely efficient -- around 80% of the energy expended by the body is converted to forward motion, even in the simplest configuration, and this can be enhanced further under some circumstances.

make3 3y ago

yeah also bike speeds keeps mechanical difficulty optimal, vs having to move your legs very fast at minimal difficulty

Ericson2314 3y ago

Reverse running, that sure sounds like a lot of tripping and falling! The power leg and the stability/control leg being opposite not the same really boggles my mind.

Ericson2314 3y ago
If we're getting really transhuman with this, assuming the brain is more malleable than the leg, I think it would actually be easier physiologically to run backwards than forwards with this. Real shape rotators will know what I mean ;)

deleted 3y ago

[deleted]