He had a special singlet designed and undoubtedly carbon shoes. Makes you wonder how much raw human potential has progressed vs just having better equipment and track surfaces?
The shoes definitely help, but there are all sorts of other innovations that get far less press.<p>More is known about optimal fuelling, hydration and sleep. Improve those and you improve your daily training. Better quality training compounds and allows you to reach closer to your talent ceiling.<p>Kerr also had a system set up so his bedroom had less oxygen than the rest of his house (to mimic sleeping at altitude).<p>He had two pacers breaking the air for the first 1,000m (although he had to do it himself the rest of the way, which was bloody impressive). Meant he could relax mentally for the first 2.5 laps and didn't have to focus on pace. I think El Guerrouj set the previous WR in a race without pacers.<p>They also had pacing lights on the track which helps the pacers run at an even pace.<p>And there are all sorts of innovations like taking sodium bicarbonate to reduce muscle acidity, nitrates to dilate the veins and increase blood flow to muscles and high doses of caffeine to reduce the rate of perceived exertion.<p>As someone else mentioned, track surfaces are generally a little bouncier now than they used to be.
> I think El Guerrouj set the previous WR in a race without pacers.<p>El Guerrouj had two pacers: <a href="https://www.youtube.com/watch?v=XvCsj7eJKKA" rel="nofollow">https://www.youtube.com/watch?v=XvCsj7eJKKA</a><p>In fact, looking at this race, Tanui (the second pacer) actually stays on the track for longer than today's pacers did.
Nitrates to dilate vessels just seems like cheating in the PED sense
Nitrate supplements wouldn't seem to meet the WADA criteria for inclusion on the prohibited substance list because they don't present a health risk to the athlete. A lot of endurance athletes are using beetroot supplements and so far there haven't been any adverse effects.<p><a href="https://www.wada-ama.org/en/what-we-do/world-anti-doping-code/2027-code-and-international-standards" rel="nofollow">https://www.wada-ama.org/en/what-we-do/world-anti-doping-cod...</a>
Where do you draw the line? (I know that the answer to that question is always 'somewhere') No one's getting significant levels of baking soda from their diet, and caffeine is a relatively recent cultural addition to most diets.<p>The gels are much the same. Getting the same nutiritional ratios used to require carefully controlled eating and certainly weighed vastly more than the gels adding both weight and complexity and likely being less performant.<p>Most(?) sports handle this by maintaining multiple leaderboards. The sub two hour 26.2 mile run was broken years ago, but the sub 2 marathon race was only recently completed, for instance. The difference being that the original was done much like this one in that it was paced, on a track, etc while the later was run in typical marathon conditions with other racers, variable winds etc.
There are off the shelf supplements that are widely used for this, e.g. BeetElite which contains nitric oxide derived from beet juice. I can testify that they do offer a real performance benefit - in my case I've found them beneficial when running at altitude as a (very) amateur. I'm not sure how/when something like this should become a banned PED.
>Makes you wonder how much raw human potential has progressed<p>Surely raw human potential cannot have progressed very much at all in the (at most) two generations represented by the 27 years the record stood.<p>Granted, the population is significantly higher, so it is more statistically likely that we've produced a genuinely faster human than existed 27 years ago.<p>I think it's fairly well accepted that most of the records being broken now are down to tech, nutrition, and aids. Springier shoes, mechanical pacers, better 'fuels', deeper understanding of exercise periodization, etc.<p>Give the old record runner all of the same boosts, the same training, I can't imagine he'd be noticeably slower, perhaps within hundreths, but I'd bet within a tenth or two.
There’s a psychological factor. Many people believed it wasn’t humanly possible to do a sub 4 minute mile before Bannister accomplished it.<p>Once that was done the flood gates opened and many others broke it in the following months. This is the “central governor” theory in endurance sports.<p><a href="https://en.wikipedia.org/wiki/Central_governor" rel="nofollow">https://en.wikipedia.org/wiki/Central_governor</a>
Not everybody who can run, runs. Not everybody who runs, runs close to their full potential. Even elite athletes have a life that can “get in the way.” Many who run close to their full potential get injured and set their training back.
I think a lot of it is also more people doing the sports.<p>We are assuming the old record is "the best a human can do because one person did it best" or some form of that.<p>There are likely hundreds or thousands of people alive right now who could break this record given the same lifestyle and training.
If it's just the singlet and the shoes you would expect lots of other runners to get close too. It's surprising that the previous record stood for 27 years if the equipment has been progressing since then.
The mention of pacemakers made me wonder if you could have some light marker on the track to show the ideal pace you should be keeping as well.<p>If you can find the human equivalent of the rabbit for greyhounds then maybe even more could be achieved.
Yep, they have that as well. You can see it in the photo here: <a href="https://www.theguardian.com/sport/2026/jul/18/josh-kerr-makes-athletics-history-by-shattering-one-mile-world-record-in-london" rel="nofollow">https://www.theguardian.com/sport/2026/jul/18/josh-kerr-make...</a>
I'm sure the track surface and shoes are important, but if "singlet" means the clothing he is wearing? It's really hard to believe that makes a material difference.
It is very easy to do the math on the aerodynamics, even at running speeds it isn't insignificant. It drives me crazy that many pro marathoners are in flappy clothes, or big hair cuts!<p>In a mile it could be between 1 and 7 tenths, depending on wind and and how bad the default outfit was.<p>And that may seem insignificant but its big margins at the elite level.
The mile record has dropped due to equipment (tracks and shoes) and pacing innovation since the very first. And I repeat this all the time but nobody listens: modern shoes are fast because of the special foam and light weight, the carbon plates have very little to do with it, experiments have cut those plates in half and running economy remains unchanged. they likely provide important structural support for the thick foam, and carbon makes sense to use for that for weight reasons, on a budget plastic is fine.
If you’re actually a runner you wouldn’t have made this comment. Give me a break