4% is a lot

The Adidas Boost was 3%

The Adizero was 2%

It's been coming a while. Nike just marketed it as such

Nobody has claimed that any shoes makes you run 4% faster.

If it were really 4% on all distances, wouldn’t Jakob be running like 3:22 now? What, with the pacing lights and all that… even the jammer suits JI wears.. and continuously optimized protocols with bioinformatic devices and such. and what about the 400 meter and 800 meter dash?

Why is the tremendous world record spree spilling into discus and pole vault, whose recent records have far exceeded any marginal benefit to equipment?

You're absolutely right that 4% is a lot.

However, I've never seen anyone suggest that runners gain a "4% improvement from switching shoes."

There's are different discussions about percentage of energy returned, etc. vs. time improvements. Data differs across different shoes for different users and races. There are some differences among studies.

If you can provide a links to an established study suggesting a level of improvement you consider "ridiculous," I'd love to see it, please.

It’s 4% improvement in running economy

Nope

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When will you witless morons realize that the track spikes aren't the same as the road shoes?

Ok boomer

Are you stupid? Nike claimed 4% improved running economy. That is not the same as 4% faster running speed.

As other people have said, I don't think it translates into a 4% improvement in performance.

However... it's still a bit dubious isn't it? If they give that much of an advantage.

Haven’t you heard, if the shoes made you faster everyone and their little sister would be running 3:24 for 1500 meters. The most likely reason every record has been broken in just 4 years can’t be technological innovation but must be a world wide instantaneous psychological evolution / change in mindset.

I don't doubt this at all, but would be interested to read the data/experiments proving this.

I'd be a little shocked if Boost allowed for a 3% drop in time- that stuff was great, but propelling it was not.

FWIW Kipchoge in his prime is probably a good point of reference - he’s probably about the most consistent performer in history and his prime spanned both “before” and “after” shoe eras. He ran 2:03:05 in London before supershoes, and eventually got down to 2:01:09, about a 1.7% improvement in performance. His current WR was on a faster course, but he was also older - I call the course and the possible slight decline with age a wash. Kipchoge with supershoes ran a marathon 1.7% faster than Kipchoge without supershoes. That seems like a reasonable approximation of the performance benefit. (Incidentally a study I saw earlier this year but can’t find now estimated the improvement in performance relative to improvement in economy was right around that as well).

Correct, and running economy is just measured oxygen consumption at a given pace, it does not translate one-to-one as running speed/time improvement. The article below claims a 4% economy results in a 3.4% increase in velocity at Kipchoge marathon pace. That seems too high to me, maybe on a treadmill, not real life outside. I like the 1.x% Kipchoge improvement estimate made by another poster.

There are other factors: some runners are low or non responders, typically heel crashers, since the carbon fiber plate is tuned to mid/fore-foot strikers. I also imagine it might be different for 100-120lb runners vs 175 lb sprinter.

Point of diminishing returns: faster speeds accrue more wind resistance, doubling speed approx quadruples wind resistance, so i'm guessing that's partly why sprinting spikes have less impact on speed. The diminishing returns is even more apparent with efficiency improvements in bikes/cars.

tritrainingharder.com

Tri Training Harder: How do the top carbon shoes make runners faster?

Jon Reilly

Over recent years there has been a boom in carbon-plated running shoes. Following Nike’s revolutionary Vaporfly 4%, most of the major running shoe brands have now developed their own carbon-plated models. These shoes are all...

Open link

Yeah like running a marathon that has a 4% downhill grade and legitimately claiming it's an actual representation of your fitness or get you in any doors (like a BQ).

4% is a lot

It's not just the shoes, baby. Try running when Paavo Nurmi ran. Like the rest of Americans he had to get up in the middle of the night to put coal in the furnace just to keep freezing to death. THAT was a whole different world!

Perhaps 4% for your hobby jogger who runs 45-50min for 10km. No where near that for elite athletes however.

For those already close to 100% of their lung capacity or close to 100% of their biomechanical limitations there won't be any 4% to "harvest" on the performance end.

I'd say the main benefit for all is an increase in recovery from less pummeling - but marketing the recovery end of things doesn't have the same ring to it as marketing the performance bit for the masses.

+1, perfectly said!