CU Boulder Scientists (Drafting Experts) Call Out & Respond to Rojo's Comments on Sub 4-Mile Attempt

There's something wrong with their calculations because she ain't going to sniff 4 minutes. 4:04 at absolute best

I said this on the other thread - the most important person in all of this (aside from FK), is Valentijn Trouw.

He is not an internal Nike guy - I don't think he really cares if Aero Nodes or a 3mm larger zoom air bag work or not. I certainly don't think he cares of Rodger Krams boffin drafting simulation is applicable in real life or not.

But I am certain he cares if she total implodes and runs herself to a standstill with a lap to go. So even though I can't see how somebody possibly can run their 1000m PR and then continue for another 609m no matter how good the pacing/drafting is, I just can't believe he would even let her go out and attempt this on pace unless it's feasible. So there must have been a 1000m or 1200m TT or some series of workouts she's done which point to this? Right?!

The only other alternative is that she is actually really only trying to run just a massive "worlds best" here - like a 4.04/4.05 low (which would be incredible in it's own right) and Nike market it as simply a "progress step" which extends this initiative a year longer or so (exactly how the sub 2 inadvertently happened)

As to why not a diamond? Well she'd have to run in lane 3 I guess for that to happen and I guess they just thought the logistics of figuring that out and executing it were a bit messy.

They can juice the tracks. (short)

Good point by Rojo that she already has pacers through 800 or so on her PRs. It’s not going to happen.

I also agree that Nike must have seen something that suggests she can get really close. I’m going with 4:03.28.

The calculations for how much time is saved from drafting never seem to play out in the real world. Kipchoge got something like 3.4 seconds per mile with all of the breaking 2 changes. I’d be surprised if she gets much more than that.

Unless there is a headwind, the main benefit of pacers is psychological, not aerodynamic. If she's in 4:07 shape, pacers might give her a 1 second/lap advantage over the last 2 laps when she's tiring because she'll get immediate feedback that she's slowing.

Computer simulations are NOT the real world. I predict 4:05.

The time savings from drafting is exponential as speed increases, so slightly more at 4 min pace. But agree they are probably overestimating the benefit, or if nothing else, there's too many other things that could go wrong and eat up seconds.

Cooper's sunglasses could fly off, whack Grant in the face, who then trips and causes a pile-up after 300 meters... I suppose they could re-start - not many rules for this one!

Ah crap, I was joking until I just saw Giles is pacing as well. He'll be the cause of the pile up.

What about the new drafting formation we've never seen before? Soon we're going to have 10 pacers for every race in the DL if this works.

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outsideonline.com

It’s the Final Countdown for Faith Kipyegon’s Sub-Four Mile Attempt

@outsidemagazine

Our Sweat Science columnist is on the ground in Paris for Nike’s Breaking4 race on Thursday

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Why are there no pacers on the inside of the track? Some sort of diamond formation, with Faith staying in lane 1.

It’s ironic that you mention Valentijn. I was discussing a very similar scenario with an acquaintance on Saturday that works for a competing group to Global SC. Though one a bit more vulgar than the other, the term in Italian, “Avere la faccia come il culo” or French, “Avoir le nez rouge” means very similar. As a VERY serious and dedicated guy, Trouw does not want GSC, Kipyegon, or himself to look foolish. When I first caught wind of this project in late Winter, I was told that the initial plans were for FK to have a normal early track season and only moving forward with the event if her fitness was adequate. The 1k early Diamond League seemed to indicate that. However, that effectively became the last that we’ve seen of her; and I have a feeling her team decided to just go all in on training for this event without further racing. I am of the thought that Sang likely set up a 1200m time trial with pacers at some point- a good outcome creating a full commitment by Nike, GSC, and FK’s team.

There's a photo on Stefan Nillessen's Instagram story showing him pacing in front of Kipyegon. Makes sense. He's a huge guy.

He wrote that he's thrilled to be involved. The photo shows Kipyegon flanked tight to her right and also behind.

The only female I've seen in the practice photos is Georgia Hunter Bell.

As I emphasized months ago, this is going to be more similar to a speed skating team pursuit or a velodrome team time trial than a standard track race. I have no idea why everyone is using visuals or reference points from a normally paced mile. Nike wouldn't be doing this if there weren't a real chance.

My primary concerns are that Kipyegon is a couple of years past her absolute prime and that it's difficult to get this type of diamond pacing and all the related variables perfectly correct on the moment in spotlight.

I'll repost what I just wrote in the other thread.

I have much publicly said there is no chance this is going to happen. When I coached the dat college the difference between 407 and 400 was VAST. From not scoring, hell maybe not even making our conference squad to contending for the win.

Today, after reading the Outside magazine article on a bizarre possible drafting formations, with 11 pacers I did think "Ok, if it happens, then that is why." I mean I have about 3 mantras I repeat about track and field and one of them is "Physics is real and doesn't lie)

2 additionally seconds for having rabbits the whole way (she had it halfway in her WR, 1 second per lap is pretty standard)
1 additional second because she wasn't right on the rabbit in her WR.
4 additional seconds for having 11 rabbits versus 1.

I'm surprised they aren't having rabbits run inside the rail. Why aren't they doing it? Why wouldn't they want any wind from the inside blocked. Blows my mind actually. Is their some scientific reason you wouldn't want even more rabbits and have them inside as well?

Outside article is here:

outsideonline.com

It’s the Final Countdown for Faith Kipyegon’s Sub-Four Mile Attempt

@outsidemagazine

Our Sweat Science columnist is on the ground in Paris for Nike’s Breaking4 race on Thursday

Open link

We have 3 articles on the sub-attempt:

Mine from April: https://www.letsrun.com/news/2025/06/running-through-time-bannister-kipyegon-and-the-meaning-of-the-mile/

Tom Ratcliffe & James Nealon: https://www.letsrun.com/news/2025/06/running-through-time-bannister-kipyegon-and-the-meaning-of-the-mile/

Mike Hahn: https://www.letsrun.com/news/2025/06/scientist-who-predicted-kipchoge-would-run-20030-says-kipyegon-will-run-401-in-sub-4-mile-attempt/

We also will be doing a live watch praty and reaction show starting 5 minutes before the race and then going on for as long as we need to afterwards:

YouTube.com

Faith Kipyegon Breaking-4 Watch Party and Reaction Show

LetsRundotcom

5 minutes before Faith goes for history and tries to break 4 in the mile, we'll come on to give you our thoughts. You can watch us react live to the race and...

Watch on YouTube

When it first came out, I thought the same thing - they won't want to embarrass her. But then I thought about it and thought, "She can probably hit 3/4th in 3:02 and that will still be exciting for fans thinking she might run a 57.9, instead of fading.

And that's basically what Jessica Hull thought when I talked to her in Philly. A 4:03-4:04 won't be embarrassing. And I'm getting a tiny bit nervous about it after readint Outside mag and seeing the bizarre formation.

It's kind of ironic that Faith's mantra is "Whatever a man can do, a woman can do."

We need an update. Whatever a man can do, a woman can do if 11 men carrying her to the finish line.

This will definitely change the way certain races are paced. Not standard open ended Diamond League races as much as ones with a specific runner targeted toward a goal time.

Then it becomes a matter of how accepting the sport and public are of the new tactics.

Oh that’s OK,

CNN will report it never really happened.

The vast majority of improvement with Kipchoge was related to the shoe technology. Drafting was a factor, but worth about 1 minute at most when you consider he ran about a minute slower in a real race.