Kipyegon Sub-4 Mile – NO WAY – it’s too hard

Sub-4 – exactly HOW will Kipyegon break the mile barrier

Olympic champion Faith Kipyegon is set to attempt an unofficial sub-four-minute mile on 26 June 2025 at Paris’s Stade Charléty. The effort, backed by Nike’s “Breaking4” project, echoes the format of Eliud Kipchoge’s INEOS 1:59 challenge that produced the first sub-two-hour marathon.

The Challenge In Numbers

Eliud Kipchoge’s Sub-Two-Hour Marathon was an improvement of 1.48 minutes or 1.22% ( from 2:01:09 to 1:59:40)

Faith Kipyegon’s Sub-Four-Minute Mile Attempt would need a 7.65-second improvement of 3.09% (from 4:07.64 to 3:59.99)

As with the Sub-2 attempt, several non-standard factors will undoubtedly make a positive difference to what a human can achieve – it’s just the magnitude of possible improvement we are uncertain of.

Course Factors

Stade Charléty (Paris) offers a certified level surface. According to the Guardian and others, it offers wide curves, minimising centrifugal slowdown.

The environmental conditions in Paris might limit wind, air density and precipitation, perhaps in a slightly more controlled environment than on the road.

My opinion: I find this very odd. A specially constructed straight track at altitude would certainly deliver better conditions for breaking the barrier in guaranteed cooler temperatures with the best track surface for the distance.

Shoe Technology

The attempt is to boost Nike’s brand image, generally and specifically, in track racing. I don’t doubt that Nike has a better shoe for the attempt – the carbon plate, foam, and other factors will be the best we’ve ever seen. I’m unsure if the shoes must comply with stack height and other rules. I hope NOT for this attempt, but they might because, no doubt, Nike will be looking to sell many pairs of shoes afterwards.

My opinion: shoe tech will deliver several tenths of seconds

Pacing Strategy

Male pacers will use a rotating “V” formation: Mirroring Kipchoge’s 41-strong pacer group, Kipyegon will be shielded from wind by a rotating wedge of elite male milers, reducing drag by up to 5% and helping maintain even 59-second laps. In addition, there will be a continuous LED strip along the rail projecting the exact sub-4 pace.

So really, what we are seeing here is digital pacing, but the ‘pacers’ are wind breaks that deliver drafting effects.

My opinion: This could be the game changer. I doubt previous records were set with so many pacers/drafters. LEDs are already used on some tracks, but this may be the first for a record.

A further thought: why doesn’t she get a running start ie run an additional 10m to get up to speed? That would save several tenths of a second.

Environmental Conditions

10–15 °C and less than 50% humidity minimise thermal strain. I would have thought Paris in the Summer would be hotter, but no doubt a morning start is planned to mitigate that. If rain is expected on the day, then this will undoubtedly increase humidity.

Wind can be a factor in stadiums; however, Pacers should negate most breezes.

Is the track the optimal surface for a mile record? Modern track surfaces do make a notable difference to running speeds. Surely a non-approved but specially customised surface could instead have been used.

My opinion: I am astonished at the choice of venue on several levels.

Training, Physiology & Psychology

I can’t see anything new here. All the proven stuff needs to be replicated.

Conclusion

It’s too difficult a task, approached half-heartedly and in a silly place. It’s probably an under-funded effort that has limited the scope of possible innovations. If achieved, this will be one of the greatest ever efforts in human history. Better than Kipchoge’s Sub-2.

I hope the project goes well, and I will watch it.