Ross Tucker Does Not Understand Aerodynamics/Wind-Tunnel

Former intern wrote:

The paid Nike trolls have been flooding the board all week. They're trying to downplay any effect of the Tesla draft so the focus is on shoes and nutrition.

Ross, I haven't seen you discuss the actual distance run by Kip vs. the actual distance run by most racers in a standard marathon. In other words, he hit perfect tangents, whereas in races most don't. I estimate this adds 200m to most races. Your thoughts?

Yeah, this is a very good point, something I didn't consider. I've not seen estimates of what a runner would do in the Berlin marathon, say, but you're right that the course marked out in Monza would allow the perfect tangents. I see there's a feature article on the Letsrun page today, and I don't think I can offer any better or more than David Katz on that one.

Ross

The Resistance wrote:

Amazing to see all these arm chair scientists saying the findings of probably the foremost sports performance scientist in the world is wrong. Lol

I don't think that at all, but thanks. I think the one point I'd make, though it likely falls on deaf ears, is that writing a website, or commenting here, or anywhere else (radio, talking to RoJo, WeJo, Jonathan etc) is NOT science, per se. It's insight and opinion offered on sport, the kind of thing I'd be more than happy to talk to a guy about over a beer, and we could argue and banter and have a bit of fun with it!

Because that's what it's about, right? This, or my website, or god forbid, Twitter! are not offered as a scientific journal, and so I think I was very clear in this latest article when I said "My opinion is that XYZ", and then I proceeded to clarify all the assumptions - why did we use the CdA of 0.4? Why did we assume efficiency 20%? What happens at different levels of efficiency?

So all that stuff if really just put out there not so much as findings, but as theories, opinions, insights. And people are more than welcome to take those on, to argue against them.

What is unfair, and hurtful (though I won't lose sleep) is the pseudoscience/egomaniac stuff, because the former assumes that I'm just guessing and making stuff up detached from certain well established scientific principle and research (which I do a lot of before I type something), and the latter assumes that people know my motives and personality. And to folk like the OP, or the others saying that, get in touch with me, and next time I'm in your city let's have a beer and chat like the fans we are about the athletes and what they're doing, and why I'm wrong and so on, and it'll be fun and educational for everyone.

Last word - when we (Roger Pielke Jr & I) did the Rob Young investigation last year, this forum was a key part of it - I acknowledged this publicly, and it even made it into the report. Some of the stuff you guys came up with was unbelievably GOOD. It was daunting to have to try to improve on the analysis some of you had done. So I'd never dismiss what I see or read here, but I would love for there to be engagement on the "WHY". Someone has recently said I'm the Donald Trump of sports science. Why? What is it that offended you so much? Trump wouldn't ask, with a desire to listen. I want to, so let's chat.

Anyway, thanks to The Resistance for the vote of confidence, but I'm happy to discuss and accept places where my assumptions may be wrong, the model may need improving. But then I want to know where they are, not simply that I'm an imbecile.

Ross

GetOffMyLawn wrote:

Can someone tell me what Ross Tucker's degrees are actually in?

I agree I would not want someone with degrees in biology or exercise physiology to spout off knowledge on fluid dynamics like they are an expert just because they went to college and studied something else. I'm sure Mr. Tucker feels irritated when the reverse happens and say a non-medical professional gives medical advice.

Happy to - I have a science degree in Physiology and Biochemistry, then a PhD in physiology, and a post-graduate in Management and Marketing (hardly relevant here).

On this particular issue, I just want to note that I didn't offer myself up as an expert in fluid dynamics. I did however speak to a few of them, and engineers, over the course of three days before and two days after the Monza race. So I was looking, in that article, to offer a translation of their model (the main one of whom is acknowledged in the piece), and not to propose my own theory. I am, however, writing my opinion based on my own insights into drafting and running physiology, because part of what that opinion is based on in analysis of performance and pacing strategy (in particular, that drafting paradox I refer to relates directly to the subject of my PhD).

I realize that this may be unpalatable, but on the fluid dynamics, I am deconstructing what I have learned, and then trying to explain it. ON the pacing stuff, I am writing from my specific PhD background.

If that means I've overstepped a boundary and presumed too much, then I apologize to the profession I've "butchered". But again, I've not sat at a computer and just done it myself - what I wrote already is almost entirely what others have informed me of.

Ross

Thanks for your thoughts, and yeah, you may be right. At least we won't have to wait until we are 70 to see it, if that is true (not sure of your age, perhaps I should not presume!)

The confidence of runners from now on will be very interesting to see - it will be fascinating, for example, to see what they ask for as a halfway split in Berlin? Will it be 61:30, suggesting the same mindset, or will they say "let's go 61" because that is the new "normal"?

I certainly didn't intend to downplay this, and it may well be the single biggest (and long-lasting/persistent) change that comes out of last weekend's performance.

I don't remember that conversation? Was it about swimsuits? I'd love to know what we disagreed on, and how that conversation ended? I mean, if you did expose me as a quack, then it helps you to be specific about that here, right? So I really wouldn't mind if you explained that rather than what is quite a vague claim. Genuinely interested to know...

Ross

El Keniano wrote:

Bombly wrote:

[quote]El Keniano wrote:

One look at his timeline is enough to conclude he's sports science's version of Donald Trump. Though I'm not even sure that's the case because a lot of what he spews feels like pseudoscience.

Not a scientist, I'll tell you that. Nor do I pretend to be one - just a mere fan of the sport and I never proselytise.

Can you give me some specific examples where my opinion on sport feels like pseudoscience? I mean, in a setting like Twitter, do to "science" would be kind of difficult, but you can't be saying "He's like Trump" and then leave it there!

I mean, I'm interested, because if this is what I'm doing, then I'd better change it, so I'm genuinely asking you, where have I behaved or said anything in a way that makes you say "This guy is like Trump?"

What I would like to offer in my defence is that I wear this hat of a scientist when I publish scientific papers and actually do research, and I'd hate for that to be thought of as pseudoscience:

And then there are instances where I'm trying to translate and communicate science, and where I think a lot of people "judge" an effort to bring a scientific insight to sport as a pseudoscience approach.

But I'm genuinely interested, because you got my attention with the Trump thing, as to what it is I'm doing? Is it because I express opinion? Scientists shouldn't do that? Is it because I have strong opinions on things that cannot be truly known, like doping? Or the relative benefit of a car vs a group of runners?

Asking not for a friend, by for myself!

Ross

Whellan Dowd wrote:

HGL wrote:

He needs to stick to his pseudo science.

Sorry to be a pedant, but if he's wrong about the Tesla, isn't he already engaging in pseudoscience? Isn't your suggestion rather like telling A-Rod to knock off the 'roids and return to his accustomed ways?

If I'm wrong about the Tesla, then I'm wrong about the Tesla, end of. I don't think it becomes pseudo- because it's incorrect. The process matters, and in the article, I've tried to explain which parts are opinion (for instance, "My opinion is that")

Then I've explained the input assumptions, and why they were made. Every one of those is "challengeable". Pseudo-science as a rule neither invites challenge not discloses the reasons for its assumptions or inputs.

And then finally, I arrive at a conclusion which I believe to be true, based on my discussions with experts in this field and substantial reading and application of other findings and theories to this situation.

I don't know where "pseudoscience" starts and ends here? I may well be wrong, but that doesn't qualify something as pseudoscience.

Ross

If the car and clock made an appreciable gain, what does say about the effort over the last two laps when the pack fell back from the car?

How hard would it be to simulate this on a quiet road and make-shift box and pack of runners of same size? Do we expect it to be noticeably different - close at all to the obvious difference when cycling in a pack at 20+mph? Could we approximate gain using heart rate comparing running with car/clock vs not?

I think we will see a more organized and disciplined approach to pace setters in future WR attempts at Berlin, London etc :

Triangle formation, more even effort 5ks splits targets (additional incentives for accuracy), a pre-planned rotation of pacers from front to back, including maybe additional rabbits to lead the pack thru 10k, 20k to aid the pace 30k setters keeping them fresh on more likely to go longer on pace

As for runners not running optimal tangents, over the past couple years I was surprised how much, the men at Boston in particular, would run middle road or far side around some rather wide long sweeping corners, like Newton area if i recall correctly) when there was no reason to : no bad road camber, shade or other good reason I can think of.

What variables, if any in your opinion, resulted in time losses during this run? I think a couple have been named in other threads: no other competitors, no crowds,

Time trailing, etc.

Ross Tucker wrote:[

I'm yet to hear, by the way, a good explanation for the pacing paradox I explained, which is important for those who believe that human drafting trumps a car in magnitude, so I'd like to hear views on that.

Ross

I don't think anyone suggests the car trumps another runner. The issue is that drafting behind another is quite effective in the first place. Pugh's famous 1970 paper suggests that when running at 6mps the cost of overcoming air resistance is almost completely removed by running 1m behind another. You cant save anymore than 100%! Therefore although the Tesla may have helped the pacemakers a bit it cant have provided Kipchoge with anything over and above that provided by the pacemakers.

Ross Tucker wrote:

ClonedDuck wrote:

Ross Tucker is an egomaniac. Drives me crazy when people take his words at 100% true. Only reason he is as well known as he is is because he feels the need to tweet about anything and everything within 30 seconds of having it happen. At the gap of 6m and going ~13-14 mph, the air falls right back behind that pace car and is left to the pacers to block.

It doesn't actually. I saw the wind tunnel models for what a car does vs having no car in front of a group of runners, and the last part of your statement is, well, an alternative fact. The air flow remains separate for a long time. Even a single bicycle 12m in front of another causes a not insignificant benefit:

http://alex-cycle.blogspot.co.uk/2013/02/pour-me-draft.html

Ross

I'd like to see those models. There's nothing to poke at, critique, and discuss without something written down for us to see. Trusting that anonymous experts know not only what they are talking about, but are not making some mistake that others might catch in review is a bit much for me.

Your point that a single bicycle 12 m in front of another causing a benefit doesn't really apply. The speeds are double and wind forces quadruple, so you'd expect substantially longer drafting distances.

150344 wrote:

Ross Tucker wrote:[

I'm yet to hear, by the way, a good explanation for the pacing paradox I explained, which is important for those who believe that human drafting trumps a car in magnitude, so I'd like to hear views on that.

Ross

I don't think anyone suggests the car trumps another runner. The issue is that drafting behind another is quite effective in the first place. Pugh's famous 1970 paper suggests that when running at 6mps the cost of overcoming air resistance is almost completely removed by running 1m behind another. You cant save anymore than 100%! Therefore although the Tesla may have helped the pacemakers a bit it cant have provided Kipchoge with anything over and above that provided by the pacemakers.

Yeah, but this is what is so paradoxical and interesting to me about other runners.

As you say, Pugh suggested that 85% of the cost of overcoming air resistance would be removed if you run 1m behind another runner. Now, the size of that reduction has huge implications for time. In a 10,000m where the guys are running at say 22.5km/h, you're talking a time saving of around 60 to 80 seconds.

But when you look at WR, what you'll see is that most of the time, guys ARE running about 1-2m behind the runner in front of them for at least the the first half. So they're getting that benefit. Or a big part of it, right? Let's be conservative, and say that they're getting 45% - that's still 40 to 50 seconds saved over the course of the race.

Yet when you look at just about every single WR since 1980, you see that they run the second half either faster than, or at the same pace as the first, despite the fact that they're getting this advantage of around 20 to 25s per 5000m over the first, but not the second half.

That seems really peculiar to me. And the same is true in marathons - Berlin every year features drafting up to 25 or 30km. And sure, it is imperfect drafting, so nowhere near this 85% theoretical reduction as per Pugh.

But that big a reduction is worth minutes in a marathon - we're talking about 2 to 3 min per HALF. So then how is it possible, that the last 5 WR have been run with more or less even or negative splits, given that the first half is ostensibly coming with this big advantage, and the second half without it?

It simply does not add up, and that's what I was getting at - the reduction due to drafting off other runners is nowhere near as substantial as it is posited, because the reality of performance does not support it. If it were, then you'd see guys running even effort in marathons, and running the second half 2-3 min slower than the first, in a world record.

That, plus the sheer size of the car and the duration for which it provides wind shelter, are what lead me to suggest that in fact, the effect of drafting other runners is much smaller than drafting behind a car with a large shield atop it.

The model has to work "in the field", and the model for pacesetters, especially on the track, simply does not work. It carries implications that are ridiculous for performance.

Ross

Hey Ross, ignore the trolls. It is just me that over the last 10 years while the marathon world best has steadily improved the average "depth" of the elite runners finishing the top races has got worse? In other words, you have two/three guys running fast times and then hardly anyone else manages to break 2.10. This as a result of a number of elite going belly up from these suicidal first half paces... I think this 2hr chimera will make it even worse going forward... I guess that's good for non-elite to grab some prices...

Keep up the good work

They apply conceptually - that was offered in response to the argument that air "falls right back into place", which it clear does not, not within 12m of a very small (by comparison) bicycle. Sure, it's going twice as fast, but I raise it to make the conceptual point, one that anyone can experience if they hop on a bicycle and get behind a tall car at 21km/h. Quantifying the magnitude, granted, is not so simple.

I think for sure that the drafting effect is real and quantifiable, but I acknowledge that knowing the relative contribution of runners and the car/clock is much more difficult. So there's agreement on the first part, not the second. I remain unconvinced of the merits of a runner in a normal situation, which I think we overestimate considerably, based on how races are paced with and without groups to run with (not just marathons - track and half-marathons provide telling examples).

That, plus the opinions of engineers and fluid dynamic experts I've spoken to, lead me to value the contribution of the car/clock more greatly. But I appreciate your viewpoint, and that you've made it here in this forum with a degree of evidence! And I don't expect you to take my word for it either!

Cheers

KAV wrote:

[quote]Ross Tucker wrote:

[quote]zxvxzcv wrote:

Hey Ross, ignore the trolls. It is just me that over the last 10 years while the marathon world best has steadily improved the average "depth" of the elite runners finishing the top races has got worse? In other words, you have two/three guys running fast times and then hardly anyone else manages to break 2.10. This as a result of a number of elite going belly up from these suicidal first half paces... I think this 2hr chimera will make it even worse going forward... I guess that's good for non-elite to grab some prices...

Keep up the good work

Thank you, and no worries. My motivation is to have a discussion, so I don't want to ignore anyone. I just wish they'd try to be constructively critical sometimes!

Anyway, you're right. It would make an interesting analysis to see if the Top 10 are now more packed or less packed than they were a decade or 20 years ago. No doubt the average of the Top 3 or 5 is considerably faster (Ken Nakamura does these great marathon stat packs before major marathons, and they show this very clearly).

But to check what happens below the top 3 - 5 per race would make for a fun exercise, and then if you could get halfway splits, I bet you'd find an increasing positive split trend since the Majors began. It's all or nothing these days!

Not sure it works quite like that. Any benefit of drafting may allow them to get to halfway at a given pace more easily, not necessarily faster at the same effort. Any benefits resulting from delayed fatigue are not necessarily equal in size to a simple % increase in speed at a given effort

Brickback wrote:

What variables, if any in your opinion, resulted in time losses during this run? I think a couple have been named in other threads: no other competitors, no crowds,

Time trailing, etc.

Good question, I think you've listed the main ones. Though I don't know that a lack of competitors is a key one - he had the pacemakers there and in a sense, the fact that there was no rival to worry about meant he was "free" to run only against the clock. I can think of half a dozen Majors in the last few years where you see really "erratic" pacing that is often brought about by competitive pressures - surges and the like. Kipchoge had no such concerns at Monza, and he did have company in the form of the pace crew. So I reckon whatever "competitive edge" was missing may have been offset by the absence of "competitive pressure".

I think crowds would be a big deal.

I wondered before whether the very early start might affect it - move everything from waking time to breakfast time forward a couple of hours, and while I know they train that early in Kenya, to race that early is mostly novel. There's also data on circadian rhythm and performance that would be foolish to apply to one athlete at a time, but it's a real factor - most people are worse early in the morning, but who knows about that for Kipchoge?

They might have done it at a lower altitude! I know there was talk of a Dead Sea attempt because it's around 400m below sea-level, and a theory that more O2 might make the difference. I'm not convinced, and nor were some altitude experts I spoke to. Besides, what you gain in O2 you lose in temp, humidity, wind etc (same as for the early start, I suppose).

Ross

150344 wrote:

Not sure it works quite like that. Any benefit of drafting may allow them to get to halfway at a given pace more easily, not necessarily faster at the same effort. Any benefits resulting from delayed fatigue are not necessarily equal in size to a simple % increase in speed at a given effort

But it does work like that, exactly, in fact, because numerous models have shown that the optimal allocation of energy for endurance exercise is even. That is, even effort, or power output, the same allocation of energy in the first and second half (throughout, in fact). A first half covered in the same speed but "more easily" suggests that a larger reserve is being maintained than is optimal, and that means that the performance is sub-optimal.

What you're suggesting is that they're spending less energy in the first half (running at a lower power output), and then cashing in on the second with more power, and that's sub-optimal for overall performance. It means that every one of those WRs should be faster, if the runner did what is physiologically optimal. But we know what happens if they go out too fast, because we see it all the time. In that situation, they should be spending equal energy or applying equal power output first and second half, but going faster the first because of a reduction in drag as they're behind other runners.

But this does not happen.

Well, in mile running (where higher speeds mean greater drafting benefits) WR's not typically set with even pace:

I don't know which of these races included pacemakers or not.

Also, elite athletes who run in packs during a half marathon accelerate more in final stages than those who don't: