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

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

#191

Post by hinkley »

ck2 wrote: post #134
303uru wrote: post #66

Earlier quoted context omitted.

Historically, human survival. No other animal can cover ground the way we can. We've evolved to be highly efficient, one example; we cool ourselves better than any other animal we can maintain a fairly high power output almost indefinitely due to sweating.

Pronghorns would like a word. Not only could they race an entire marathon, they would beat those inline-skaters. 30mph for hours and 150 miles in some journeys. They evolved a different cooling system than sweating. https://journals.biologists.com/jeb/article/211/5/749/18118/...

We have a cluster of veins at the base of the skull that dumps heat on the back of your neck after the blood reaches the brain, which is a similar convergent evolution. In the mid 90’s when I took an anthropology class, they had just worked out that the human family tree needed some adjustments based on the presence or absence of these ports on the edges of the occipital bone. These radiators were important to our big brain evolution. Without extra heat dissipation we’d cook our noodles. Humans with fevers over about 104-106 risk brain damage. It’s why willow bark tea and later aspirin were such pivotal discoveries.

(Recently learned that aspen bark also contained salicylic acid, which is how aspirin got its named).

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

#192

Post by hinkley »

stouset wrote: post #143
jdietrich wrote: post #120

Earlier quoted context omitted.

>the contribution of the lifting leg is crucial to getting up to speed This might feel true, but it isn't. Buy or borrow a dual-sensing power meter (Garmin Rally, SRM X-Power etc) and you can see for yourself - there's practically no useful power in the upstroke. Toe clips or clipless pedals can extend the power stroke, but only by a few degrees at the bottom of the stroke. https://bythlon-pedal.myshopify.com/pages/t…

I strongly encourage you to actually test this yourself. Having personally done so myself, all I can say is that you will be surprised. Time yourself on a max-effort sprint in a high gear from a standstill. Don’t pull up on half your efforts. Pull up on half your efforts. The effect isn’t subtle. I’m not particularly convinced by power meters not showing much here. The biggest reason being that pulling up has the eff…

The summaries of these studies don’t seem to mention sprinters. Or climbers. I’m thinking the wrong people did these studies (people who didn’t actually “test it themselves”).

I would also say that as a former cyclist and bike mechanic, there were thresholds of pedal adjustment where your foot would stay on the pedal if you only applied downforce, but not sufficient for any other force. It was a common enough problem that there were articles written about it.

Early Look models had this problem, but not as substantially as most of their copycats. There’s a reason they had little competition for most of a decade. I think the Shimano MTB pedals (with the little countersunk cleats) sometime around 2nd Gen, were the first time Look got properly nervous.

There were some people for whom you had to dial the tension to the edge of “annoying” for clipping in in order to keep them from accidentally clipping out at speed or on hills, both if which can be dangerous.

Even when I had mine dialed in “right”, I ended up pulling one shoe vertically out of the pedal when I came to a stop without disengaging first. Adrenaline is a hell of a drug.

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

#193

Post by rhn_mk1 »

tourist2d wrote: post #82
rhn_mk1 wrote: post #69

Earlier quoted context omitted.

Those are not necessarily examples of lifting . Those could as well be explained by the contribution of not pressing on the opposite pedal (to keep the foot from sliding). And not pressing doesn't shine any light on the force of lifting.

> to keep the foot from sliding So you obviously have never used clip in bike pedals before. Why are you trying to argue this point if you know nothing about what you're talking about?

If you're clipped in, why would you keep feet from sliding?

Preventing sliding by pushing is how effort is wasted and is a possible explanation why a cyclist might feel much stronger when clipped in and no longer has to push - while attributing the lower effort to the upstroke pull.

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

#194

Post by Forgeties79 »

solumunus wrote: post #155
Forgeties79 wrote: post #130

Earlier quoted context omitted.

Hey there! I don’t know what you’ve done to treat it so far, but I am somebody who went through a year and a half of very painful plantar fasciitis after a few years of moderate pain. I tried every single solution under the sun and am actually “cured”! Some unsolicited input, if you want: 1) Kuru tennis shoes with an insert for PF are excellent. 2) Oofos slippers by my bedside even today. They provide such good relie…

> ultimately had to get my plantar fascia released What does this mean?

It’s an outpatient procedure where they, to be super simplistic about it, cut the plantar fascia and have it regrow. When successful, the inflammation that has been recurring is essentially “removed” as a result. The new tissue doesn’t just start with it. They told me the recovery would be 2 to 3 months, but it was definitely longer.

It’s an old procedure at this point that different doctors have different opinions on. In my case, I had a second opinion from a doctor who thought he was going to tell me no, but then he looked at my history of treatment and went “yeah at this point, you have no other option. It’s this or live with what you’ve got and I would say go for it.” Considering he was going in prepared to tell me no that was actually very encouraging and I’m glad I did it. But it does not mean it is for everyone, I highly recommend if you are considering it to get two or three opinions on it, and to exhaust all your other options.

By that point I had pretty much integrated every single piece of equipment that could give me a relief and had done multiple rounds of steroids - both oral and injection. It would always get close to getting better, then would start re-inflaming. I’m 18mo out now and doing great.

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

#195

Post by tech_ken »

culebron21 wrote: post #180
tech_ken wrote: post #19

Earlier quoted context omitted.

No, the difference is when/how you load the springs. This proposal seems to be that you load the spring with your leg in the air before it makes contact with the ground (achieved by attaching the top of the spring up the leg), then land the loaded spring and unload. Their argument is that this allows for higher overall energy output from the human body (akin to cycling). In a jumping stilt you're loading the spring w…

Actually, you're right, now I recall it better, you swing arms in the bottom point, to compress the spring better. Waving arms in the air does not help.

Regardless of when you swing your arms, by doing so you're introducing additional energy into the system so is kind of beside the point. The relevant comparison (in the context of their paper) is how fast you can convert chemical energy into kinetic through your gait, not how much chemical energy you can load into the springs. Jumping stilts are a 4-step cycle:

1a. LOAD (Foot-ground contact, foot is descending)

2a. UNLOAD (Foot-ground contact, foot is ascending, optionally arms swing to boost upward force)

3a. WAIT (No foot-ground contact, foot is ascending)

4a. WAIT (No foot-ground contact, foot is descending)

Their proposal is 3-step:

1b. LOAD (No foot-ground contact, foot is descending)

2b. UNLOAD (Foot-ground contact, foot is ascending, optionally arms swing to boost upward force)

3b. WAIT(No foot-ground contact, foot is ascending)

Step 1b performs the same function as both Steps 1a and 4a, but is closer to Step 4a alone in terms of duration. By reducing the overall time one cycle of gait takes you're able to convert the same amount of energy from chemical to kinetic in a shorter amount of time (ie. achieve a more powerful gait cycle). This presumes that you can achieve equivalent levels of energy input with both methods, but this doesn't seem like a huge reach to me since both methods rely on springs so presumably you could fiddle with the spring constants until the overall energetics are the same.

It's kind of like how an 18-wheeler can produce tons of torque (which it needs to move something heavy), but has less horsepower than a Porsche. Torque is what determines how much weight you can haul (or in the case of jumping stilts, how high you can go), but horsepower is what determines how much time it takes to go from 0-60MPH. Swinging your arms is like adding more torque, but the paper is about maximizing horsepower.

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

#196

Post by karmakurtisaani »

hinkley wrote: post #186
karmakurtisaani wrote: post #162

Earlier quoted context omitted.

Those springs look like a great way to get rid of any unnecessary teeth. Can't achieve that with a bicycle.

I know some people who tried.

Losing their teeth riding a bike? How did that go?

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

#197

Post by hinkley »

karmakurtisaani wrote: post #196
hinkley wrote: post #186

Earlier quoted context omitted.

I know some people who tried.

Losing their teeth riding a bike? How did that go?

They were head over heels about it.

Seriously though, if you don’t have your helmet adjusted about as far forward as it can comfortably go, there are a number of angles at which you can take a header where part of your face touches the ground. If you’re lucky nothing hits but helmet. Less lucky, a bit of road rash. Less lucky still, maybe some loose teeth.

The higher speed collisions I heard about mostly involved back injuries, which is less fun than artificial teeth. Younger people try to face plant.

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

#198

Post by moron4hire »

muststopmyths wrote: post #144
moron4hire wrote: post #109

Earlier quoted context omitted.

I wonder if that would do anything for my plantar fascitis... I made a mistake in shoe choice for a vacation one year, before I knew how much my wife absolutely insists on walking at least 10 miles a day. That was 8 years ago and I still have pretty severe pain almost every morning.

when I had plantar fascitis the only thing that helped was finding the right running/working out shoes. It was like magic in how quickly that fixed it. In my case, I needed shoes with more support around the mid-foot so the feet didn't rotate in or out too much. The flip side is that as soon as I wear the wrong kind of shoes my feet let me know within a couple of workouts. I also wear superfeet insoles in all my casu…

This sounds like my problem. I do have an over pronation problem when I walk barefoot. I have arch supporting shoe inserts, but I think my sneakers allow too much ankle roll.

I have Brookes right now. They felt good when I first got them, but they just didn't hold up. I think my local shoe store must have too many Brookes shoes. They push them really hard every time I go.

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

#199

Post by culebron21 »

tech_ken wrote: post #195
culebron21 wrote: post #180

Earlier quoted context omitted.

Actually, you're right, now I recall it better, you swing arms in the bottom point, to compress the spring better. Waving arms in the air does not help.

Regardless of when you swing your arms, by doing so you're introducing additional energy into the system so is kind of beside the point. The relevant comparison (in the context of their paper) is how fast you can convert chemical energy into kinetic through your gait, not how much chemical energy you can load into the springs. Jumping stilts are a 4-step cycle: 1a. LOAD (Foot-ground contact, foot is descending) 2a. U…

Ok, makes sense. But I wonder: if it's so hard to run in jumping stilts (which I know personally), does it make sense to make another device that can consume your muscle energy?

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

#200

Post by tech_ken »

culebron21 wrote: post #199
tech_ken wrote: post #195

Earlier quoted context omitted.

Regardless of when you swing your arms, by doing so you're introducing additional energy into the system so is kind of beside the point. The relevant comparison (in the context of their paper) is how fast you can convert chemical energy into kinetic through your gait, not how much chemical energy you can load into the springs. Jumping stilts are a 4-step cycle: 1a. LOAD (Foot-ground contact, foot is descending) 2a. U…

Ok, makes sense. But I wonder: if it's so hard to run in jumping stilts (which I know personally), does it make sense to make another device that can consume your muscle energy?

Can't speak to that one! Just interested in the math
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