Was 2:01:39 really a big breakthrough? After Breaking2, Ross Tucker predicted a 2:01:40!

Energy efficiency is 25% maximum, in ideal weather the remaining 75% being heat production.

Andrew Hamilton:

Generally, larger animals (like humans) tend to be a little more efficient during running than small animals like mice, for reasons that are not exactly clear. The real paradox is this, however: when muscles are stripped from the legs of freshly killed mice and tested in the laboratory, they operate with an efficiency of 25%. That same experiment can obviously not be carried out with humans, but it is known that when humans ride bicycles, their efficiency is also about 25%. Why is running such an inefficient process for mice and so efficient for humans? When mice run marathons, their efficiency of movement drops from 25% to just 3%, while for humans efficiency during running soars from the 25% achieved during biking to 50%! The answer to the mouse question is unknown, but the key to the human running response is obvious. Each time a human foot hits the ground while running, energy is stored as ‘elastic strain energy’ by the key ‘springs’ in the human leg – mainly the connective-tissue strips which run along the bottom of the foot, the Achilles tendon and its associated muscles, the relevant muscles and tendons around the knee and the relevant muscles and tendons surrounding the hip. All of these structures are stretched when the foot hits the ground, and this stretching process stores energy – i.e. increases the potential energy of the leg. When the structures recoil elastically during toe-off, they manage to return about 90% of the work required to stretch them (with only 10% lost as heat). If the tendons and muscles of the leg were not able to store energy during impact with the ground, the muscles would have to increase their work output and energy expenditure dramatically. In fact, Alexander estimates that when humans run at middle-distance speeds, the spring-like properties of the Achilles tendon and the arch of the foot alone cut the work the leg muscles have to do by half. Here lies the answer to our paradox: human leg muscles are still working with only 25% efficiency during running; they do not really become more efficient just because running is the chosen sport. If the mechanical cost of movement is two joules per kg body weight per minute, half of this cost is furnished almost for free by the legs’ springs. Thus the muscles cough up four joules per kg per metre to provide the other joule per kg/metre of mechanical cost – with an efficiency of 1/4 = 25%.

The bottom line for you as an athlete who uses running in your chosen sport is that the best way to decrease your cost of running – and thus run faster and longer – is by enhancing the function of your leg springs. Since they are able to store energy more effectively when the foot hits the ground and then release this energy more fully and in a more timely fashion during push-off, your metabolic cost of running at a specific speed will drop, and you will be able to move up to higher speeds during training and racing.

That math is wrong and whether muscle efficiency is 40% or 25% is completely irrelevant. Efficiency as defined by the Vaporfly studies is running economy, i.e. velocity per volume of oxygen consumed. This means if efficiency increases 4%, velocity should also increase 4%. Since elite runners obviously aren't improving their times by 4%, this means either 1) the studies were wrong or 2) the science behind running economy is invalid and useless.

re: Tucker's "prediction"

Even a broken clock is accurate twice per day.

Tucker after Breaking 2

" I reckon Kipchoge, in a race like Berlin, is probably capable of 2:02:00 to 2:02:20."

and Tucker's prediction a few days before Breaking 2 2:00:25

"If Kipchoge can get to 30km in around 1:25:30, and then hang on to run the last 12km at about 3 min/km, then he’s going to run 2:02, which is my prediction for the perfect day."

yeah, he's always spot on.

and let's not forget this prediction

https://sportsscientists.com/2013/07/a-double-amputee-will-soon-medal-in-able-bodied-olympics/

Edgar Poe wrote:

How can someone that intelligent continue to fail to realize that the 4% refers to EFFICIENCY. This has been stated ad nauseum.

It's simple, he's not very intelligent at all. Dumbed-down science to impress the dumbed-downed masses.

Morans

real scientist wrote:

Edgar Poe wrote:

How can someone that intelligent continue to fail to realize that the 4% refers to EFFICIENCY. This has been stated ad nauseum.

absolutely. the map from energy input to pace is highly non-linear due to various factors. in other words, even if the shoes are 4% more efficient in the sense that for the same pace, you spend 4% less energy, that doesn't mean you'd run 4% faster if you spent the same amount of energy. similarly, if you improve two factors like shoes + nutrition by 1% each, you don't necessarily get 2% as combined effect.

really basic stuff. I don't expect the TV pundits and the T voters on this board to understand this, but a sports scientist should know better.

Haha, yeah the H supporters are so much smarter than the T voters. Your statement about the T voters completely invalidates anything resembling intelligence in your post.

real scientist wrote:

Edgar Poe wrote:

How can someone that intelligent continue to fail to realize that the 4% refers to EFFICIENCY. This has been stated ad nauseum.

absolutely. the map from energy input to pace is highly non-linear due to various factors. in other words, even if the shoes are 4% more efficient in the sense that for the same pace, you spend 4% less energy, that doesn't mean you'd run 4% faster if you spent the same amount of energy. similarly, if you improve two factors like shoes + nutrition by 1% each, you don't necessarily get 2% as combined effect.

really basic stuff. I don't expect the TV pundits and the T voters on this board to understand this, but a sports scientist should know better.

Yes, a reduction in TIME of 1.3% would be absolutely huge if down to the shoes. It would be a bigger increase than the 4% efficiency saving that Nike are claiming.

If a spike came along that makes a runner 1.3% faster then Korir would run 1:40.6 from his 1:42, Cheruiyot will run 3:25 and Barega will run 12:30.

4% time reduction means a 2:20 marathoner will suddenly run 2:14 simply by tying up some Nikes. I don't think even the Nike marketing team would claim that.

Sledge_hammer wrote:

How some people think a pair of shoes can help you run a minute faster is beyond me.

Exactly. Jason Rexxing ran 13:55 in trainers.

As for mere mortals like Kipchoge and Kimetto/Bekele/Kipsang, shoes are close to a level playing field. Nike has their 1% shoes, addidas has Boost foam, which they've studied to add 1% to running economy.

In the end, there is no +1:10 to asterisk to this race, when the next 5 fastest times (including the world record) were run in shoes supposedly adding +1:10 as well.

To be sure, yes, I do think the shoes played a very big part. Kipchoge being the outlier that he is, my personal belief is that he would not be getting a 4% increase (resulting in .95% faster) as was the average when Nike tested sub-elites wearing the Vaporfly against the Zoom Streak 6 and Adios Boost 2 that Kimetto wore when he went 2:02:57. Let's say he still got half of that, though, or about 30-40 seconds from the shoes. That's clearly very significant and I believe Kipchoge himself understands this as he can run in any shoe he chooses to and, well, he chooses the Vaporfly so there must be something to it.

The demi-god tongue-in-cheek line is mostly because I just adore the guy. Can a man say that about another man? I don't know, but I seriously do. Everything he does I find incredibly inspiring. I can't run anywhere near as fast as him so it's difficult for me to fully appreciate just how special his time is. I know it's moved the human population a great deal closer to sub-2, but I don't know what the sensations are like that he feels. It must be amazing.

What I can relate to are his quotes and anecdotes. I've watched the talk he gave with Dave Bedford at Oxford quite a few times. I have a perma-grin the entire time I watch it whether I'm sober or not. I really want to transcribe the closed-caption better than what is auto-generated by YouTube because in my opinion what he says there explains why I call him a demi-god. It's his view of life more than anything, not just because he's a world record holder that only becomes more humble with each additional success. He does what he knows he's supposed to. I want to be free like him with such fierce and unrelenting discipline.

A note about someone saying efficiency can not exceed 25%. That is about the range for concentric muscle contractions. You'll see efficiency numbers like that thrown around in cycling studies because there is very little eccentric component to it. The stretch-reflex happens unconsciously and is considerably more efficient than a concentric contraction. I don't have my Verkhoshansky books with me as I'm on vacation, but if I recall correctly he stated efficiency for eccentric contractions was around 42-43%? Or was it running in general? Now I'm not so certain. Maybe the concentric contractions are in the 23.6% range and eccentric closer to 61.8% and the two average out around 42-43%? Whatever the case may be, more energy can run through the body of a runner than a cyclist in the same amount of time due to the role of the eccentric phase while running that is essentially absent in cycling. It's little wonder that cyclists must train about 2 to 2.6 times as much as runners; they are transmitting that much less energy.

Oh shoot is this the boss man behind the study Wouter Hoogkamer?

dumb luck wrote:

re: Tucker's "prediction"

Even a broken clock is accurate twice per day.

Exactly. Who is Ross Tucker anyway?

mind expanding wrote:

After the Nike attempt Kipchoge knew his body could handle at least 2:00:25. This familiarity could not have been obtained in an actual race.

Bekele and Kimetto need a go too. But Nike must have spent a lot of money on that glorified training run.

Or maybe it will be like the aftermath of Bannister's sub 4 minute mile when other runners began to do it too.

everyone goes on about how much money was spent by nike. that thing was less expensive than a superbowl commercial. It was in fact a 2 hr commercial for nike. and it is the ONLY marathon in the last 10 years that I sat and watched from start to finish. They didn't lose money they made money on it.

The relationship between efficiency and velocity are not linear and therefore an improvement in efficiency of 4% does not result in the same increase in velocity.

Really really basic sports science here guys. If you dont understand it you should refrain from spreading your pseudoscience based OPINION.

gads wrote:

The relationship between efficiency and velocity are not linear and therefore an improvement in efficiency of 4% does not result in the same increase in velocity.

Really really basic sports science here guys. If you dont understand it you should refrain from spreading your pseudoscience based OPINION.

Well if it's so basic, why don't you explain it?

Please share your bioengergetic efficiency AND biomechanical efficiency model with us o wise one?

Hardloper wrote:

Edgar Poe wrote:

[quote]automorphic wrote:

[quote]Edgar Poe wrote:

"So I've actually heard that a 1% improvement in efficiency DOES correspond to a 1% improvement in pace."

Blatantly false information passed off as fact. Someone is dishing out black pearls. They'd fit in great on this site.

Why is it false? Efficiency = pace divided by energy, measured by oxygen consumption in this case. In the lab tests that 'prove' the 4% increase in running economy, athletes were supposedly able to run 4% faster with the same oxygen consumption as before. Assuming that's true what's stopping them from racing 4% faster?

Measures for oxygen consumption are refered to as running economy, which is not the same as efficiency, because the anaerobic contribution is missing. The anaerobic contribution to marathon running is much higher than you might think.

Jefe in the CO wrote:

Let’s take our sport down a couple more notches by reverse engineering Mondo tracks to cinder.

You could keep the Mondo but also reintroduce cinder tracks, grass tracks, and the old tartan tracks. In this way, Track and Field becomes more like the tennis grand slams on different surfaces. It would increase interest in the sport.

Saved efficiency will help in longer races. Maybe Kipchoge was topped out speed wise first 20 miles of the race. No amount of efficiency could have made him run faster. However, what he saved in energy during that time he was able to prolong the pace for another 6 miles. I flatly don't believe he would ran sub 2:03 in any other shoes.