What it would take for Faith Kipyegon to become the first female sub four-minute miler

New York Times

a day ago

It's all very 2017. You take a Kenyan Olympic champion in their prime, hand-pick a course in Europe, dress them in your latest innovative kit, place them behind a pacemaking team, and try to break a barrier once thought impossible.
On Thursday, at the Charlety stadium in Paris, Faith Kipyegon will attempt to become the first woman to run a sub four-minute mile.
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Eight years ago, it was Eliud Kipchoge at the Monza track in Italy — along with the often-forgotten Zersenay Tadese and Lelisa Desisa — trying to run a sub two-hour marathon. That event was called Breaking2; this is Breaking4.
Like with Kipchoge, the finer details of the plan mean the time Kipyegon posts will not be world-record eligible.
Nike has termed Kipyegon's attempt, as it did with Kipchoge and company, a 'moonshot'. When Kipchoge came up 25 seconds short in Monza, the feeling was that the sportswear company had shot for the stars and landed on the Moon.
Kipyegon's 'moonshot', proportionately, is being launched from even further away. Success requires her to run at least 7.65 seconds faster than her own world record for the mile, set in Monaco two years ago.
Since 2017, she has trained under coach Patrick Sang with the Kaptagat-based NN Running Team in Kenya. Kipchoge, her mentor, is part of that group — the 31-year-old is one of the few athletes who can match his glittering career.
Last summer, Kipyegon won her third Olympic 1,500m title, bettering her own Games record time of 3:53.11 from Tokyo by nearly two seconds (3:51.29).
That made her the first to successfully defend the Olympic 1,500m title twice in a row. Kipyegon can, only just, still count her Olympic and World Championship medals on both hands — 10 in total, with seven golds, having won her first, a silver, nine years ago at the 2015 World Championships.
Paris is her happy place. It was where she had that Olympic success last summer, and Charlety is the track where she both lowered her own 1,500m world record last July (down by seven hundredths to 3:49.04) and broke the 5,000m world record in June 2023 (14:05.20).
To understand what it is going to take to try and achieve this, The Athletic spoke to three experts who all contributed to Breaking2 in 2017:
There is a distinction to be made here: Kipyegon is extremely quick, but she is not inherently fast.
She rarely races 800m, and her 1:57.68 personal best in that event dates back to 2020. That should, and absolutely could, be lower, though typically the exchange rate for a four-minute mile is an 800m best in the low 1:50s.
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Great Britain's Jake Wightman (the men's 1,500m world champion in 2022, when Kipyegon won the same women's title) spoke last year about being 'able to race up and down' distances.
Wightman is better at 1,500m and below, whereas Kipyegon races up better. She was only focused on the 1,500m world record in summer 2023, when she broke that, plus those for the mile and 5,000m, despite the latter being her first race at that distance for eight years.
Kipyehon's strength is speed endurance. At 5ft 2in (157cm), she is small, and trains primarily with marathoners.
The challenge of racing down was proven — again — just this April.
Kipyegon's third attempt at breaking Svetlana Masterkova's 1,000m world record (2:28.98, from 1996) saw her run yet another 2:29-something.
Kipyegon finished fast, and it was a season opener in Xiamen, China, that she won by three seconds, so had limited pacing or drafting support. It was also an unofficial dry run for Breaking4 — she averaged four-minute-mile pace almost exactly, and told Diamond League media afterwards the race was to 'see how fast I am'.
Andy Jones, a Professor of Applied Physiology at the University of Exeter, is a leading researcher in the physiological determinants of endurance exercise performance. He was an endurance expert for Breaking2, and has continued to collaborate with Nike.
The challenge is the mile being a 'supramaximal' event, he says: 'The energy demand is above the VO2 max (about 115 per cent — see below), so the aerobic system is taxed maximally and the additional energy requirement has to be met by anaerobic energy sources.'
Jones co-authored a research paper published in late April (just three days before Kipyegon's 1,000m record attempt in China) where they 'speculate' on the physiological demands of a female four-minute miler, based on men who have achieved the feat.
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He says he 'can't say anything about what was or might have been done with Faith', for obvious reasons, but interestingly in the paper they conclude that 'there is no female athlete presently displaying the physiological characteristics required to run a sub-four minute mile'.
'There are various aerobic/anaerobic combinations that could enable someone to run sub-four, but it helps to have a high VO2 max,' Jones says.
That is a measurement, per kilogram of body weight, of the amount of oxygen an athlete can take in every minute during exercise.
Kipyegon went to Nike's HQ in Beaverton, Oregon, in January for VO2 max testing, as well as body mapping and baseline testing. Nike has a track built inside the lab there which is fitted with force plates, which means they can test her in spikes.
Brad Wilkins, who led the Breaking2 'Science Team', says they tested potential marathoners for VO2 max, running economy (how efficiently they use oxygen) and critical/sustainable speed, which is the highest pace that can be sustained for long periods without fatigue.
They also looked for something more 'squishy', as Wilkins describes it — the capacity to show psychological resilience when suffering physically.
'I like to tell this story of Zersenay when we were done testing him,' he says from the United States, where he now directs the University of Oregon's performance research laboratory.
'It was all over. He could have just gone back to the hotel room. But we were just like, 'Hey, we want to see what it would look like to run at two-hour marathon speed (21km or 13mi/h). Would you get on the treadmill and run at this speed? Just to see how it goes'.
'I think his answer was, 'How long do you want me to go?'. That was another important component that doesn't get talked about a lot.'
Jones says that something called 'VO2 kinetics' is particularly important for the mile. The term references 'how rapidly (an athlete) can attain their VO2 max after the race starts,' he explains. Think of it as not just having a big engine in a car but a fast 0-60mph, too.
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A person with a high VO2 max and fast VO2 kinetics 'would need a lower anaerobic capacity than someone with a lower VO2 max and slower VO2 kinetics.'
The question is not about Kipyegon hitting the necessary speed or holding it for 1,000m, but at what point before the finish she hits the red zone. Jones describes it as a 'delicate integration' of energy systems.
Wouter Hoogkamer knows that drafting matters because it was a fundamental pillar of Breaking2, before the super shoes took the headlines. He calculated that reducing air resistance by 36 per cent would be enough to turn a 2:03 solo marathoner into a sub-two-hour one.
Then, Hoogkamer was a researcher at the University of Colorado. Now he runs his own lab at the University of Massachusetts, near Boston.
'We realised air resistance is even more important for a four-minute mile, one because of the pace, and two for women, because they're relatively smaller,' he says from that lab. 'We took the simulation data and considered the whole range for drag forces, how much they change with different drafting formations, and put those into our model which can estimate metabolic cost differences.'
He is speaking about another paper he coauthored that was published in February. Hoogkamer and the three other researchers 'saw Kipyegon's mile record and 1,500m records — they weren't optimally paced. There were pacers, but she wasn't fully behind them all the time.'
They found she only ran behind pacemakers for 900m of the mile and, even then, the spacing was sub-optimal.
That meant the energy demands increased disproportionately, despite her splitting the race evenly — 62.6, 62.0 and 62.2 seconds for the first three laps were only matched with drafting effectiveness of 22, 30 and eight per cent. The magic number for drafting effectiveness, as per Hoogkamer's modelling, is 71.9 per cent.
Her finishing kick, covering the final 409m in 60.85s, was done alone. Hoogkamer is quizzical about what that could be with better support. 'Can she save that much energy early on by being fully packed-in, out of air resistance, so that, in that final lap — still in a good pack — she can actually maintain that effort? If she is behind people, that effort is going to get her a couple of extra seconds (off).'
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He caveats that the research base on running aerodynamics is limited and studies take different approaches — 'wind tunnels, simulation papers, computational fluid dynamics' — but believes, with effective pacemaking and drafting, five or six seconds should be saved.
They are, Hoogkamer accepts, talking about 'the perfect scenario, perfectly executed. She has to be behind people for the whole thing.' His model has a time of 3:59 as achievable.
'That also involves her being at exactly the same fitness as back then (summer 2023). We won't be able to tell, because she is also going to be wearing different shoes,' he says.
'I think there's a fair chance she will just beat it. If you need eight seconds, it's going to be a split where the bulk comes from the air resistance and then the last two to three seconds could be from this personalised/optimised spike.'
Kipyegon will be running in a bespoke spike — which she wore a prototype of in that 1,000m world-record attempt in April — plus a speed suit (with matching arm and leg sleeves) and a 'one-of-one' 3D-printed sports bra.
'The other thing, to be executed perfectly, involves running close together for the whole thing,' Hoogkamer adds. 'The biggest problem is you don't want to be tripping. It's one way to put a very tall, big runner in front to block more air, but if that runner has to be further ahead of her, so that their legs don't interact at a lower cadence (that's a problem).'
Hoogkamer smiles as he says: 'Ideally, I'd see a triplet of Kipyegons — one in front, one behind, and all running the exact same cadence in phase (ie, with matching stride).'
The benefit of adding someone behind Kipyegon so that she is sandwiched between pacers is 'not really something that people think about that is helpful,' Hoogkamer explains.
'The way aerodynamics works is you have a pressure buildup in front, but you also have negative pressure behind the runner. That pulls them back slightly. If you have another runner behind them, you can put that negative pressure further behind the designated runner.
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'Either you put her behind men, or you put her behind women who take turns, like Breaking2 (with rotating pacemakers).'
Being on a track means it is not realistic to repeat the arrowhead drafting approach Nike and INEOS used in their sub two-hour marathon quests.
There has been no announcement on the official pacing strategy for Thursday, though there have been teasers from athletes on social media and also in the first episode of a two-part Prime Video documentary which is following the event.
When Nike visited Kipyegon's training group, it trialled (Kipyegon was not present) a five-person, sideways V formation, with two runners ahead and three behind.
This was designed to mitigate for having to run bends to the left on a 400m track and trying to maintain the 'air pocket' that she will sit in as they turn.
Georgia Hunter-Bell, the 1,500m bronze medallist at last year's Olympics, has said on social media that there will be a mix of male and female pacers, 'familiar faces' in terms of elite-level athletes who race on the circuit, plus some of Kipyegon's training partners from Kaptagat.
Kipyegon returned to Kenya after that 1,000m in April, not needing to run qualifying standards for the World Championships in September as she gets wild-card entry as the reigning gold medallist from 2023.
In the remote Breaking4 press conference, she said her workouts hadn't changed: 'The mindset is different but the goal is the same — dreaming of achieving what is inside me, which is breaking four.'
The plan has her running seven days a week, featuring a solo long run on Sundays and a team long run on Thursdays. Track sessions are twice weekly: Tuesdays are volume-focused, Saturdays are all about intensity.
She has been doing 43-second 300m repeats at 2,500m (8,200ft) altitude in Kaptagat. That pace equates to 3:51 per mile, and is designed not just to condition her physically and sharpen mechanics, but to make her comfortable mentally with running at 60-second lap speed.
One of Wilkins' primary research areas is female sex hormones and their impact on performance.
He hopes that Breaking4 can contribute to more and better research into training elite female runners — 'the amount of data that we have on these (women's) topics is significantly less than what we have on male performance, or even testosterone and its performance impacts.'
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There are plenty of female-specific parts of training and physiology that Wilkins says academics 'just don't know'.
'We need to understand the physiological underpinnings, performance limits in relation to fluctuations in sex hormones, and fluctuations or differences between males and females,' he adds.
The problem, he explains, is that without a real research base to help inform practitioners on female athletes, things may be sub-optimally tailored: 'I honestly think the philosophy of training and performance is just being transferred (from men to women).'
He is mindful this sounds like a loaded comment — 'that's probably going to get me in trouble' — but his intention is to be objective.
'Essentially, the training plans, approaches and strategies are the same as men — different levels, different loads, but the overall periodisation, the overall application of those loads is pretty much the same,' Wilkins says.
'I think that's wrong, an inaccurate way to do it. Why don't we have the information to say that, for endurance performance, women shouldn't be doing a lot more sprinting, a lot more power-type work to get bigger muscles and to get faster? Because we know that they are more fatigue-resistant, they can go long periods of time, probably better than men, but they don't have the power. Maybe we need to train that, and we don't need to train endurance as much.'
Nike has a similar problem with Kipyegon as it did with Kipchoge eight years ago.
Wilkins explained that Desisa and Tadese were wild-card picks, the latter especially as he had run a 2:10 marathon without taking on any hydration.
'Eliud should have been running as fast as he was because he had the resources and a team around him,' Wilkins says. 'Some of the others, we were like, 'Let's give them that and see what they can do, because they have the potential'.'
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Kipyegon's first Olympics was London 2012, running 1,500m. She first set a world record in 2014, as part of a 4 x 1,500m Kenyan team at the World Relays, and her first global individual medal was a silver at 1,500m in the 2015 World Championships.
There are few obvious areas to make gains, and while the per cent gap from the world record to the barrier is bigger than what Kipchoge tried to jump in 2017, Kipyegon has one edge over her compatriot: he had not set a world record before Breaking2.
Wilkins says he 'learned from Eliud that there's a difference between believing and knowing'. After Breaking2, 'he no longer believed he could do it, he knew it. His ability to focus and train harder now that he knew he could run that fast was the reason why he did it the second time.'
Similarly, Kipyegon has said going back to the tape of her Monaco mile world-record 'really helped me review how fast I was.
'When you watch yourself running the same race (again), you can get an idea of what you are going to change.'