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David S
RE: Saucony's Jared Ward publishes scientific paper showing that Nike's 4% shoes really do work

runner 523 wrote:

2.7% 10k? wrote:

I wonder what the lower end of the distance spectrum is for improvement? 2.7% improvement for marathon/half/...10k??? That would equate to like 52 seconds for a 32 minute 10k runner. That’s huge.

The study said 2.7% more energy efficient, not faster though. Anyone know how that translates to time in a distance race? I have to imagine it's a smaller % boost.

Quoting from their paper:

The changes in running economy are encouraging, but athletes need to know how that translates to performance times. For every 100g of added mass to shoes, there is a 0.8% increase in metabolic cost, which leads to an increase of 0.78% in performance time (Hoogkamer et al., 2016 Hoogkamer, W., Kipp, S., Spiering, B. A., & Kram, R. (2016). Altered running economy directly translates to altered distance-running performance. Although the differences we observed were due to shoe type rather than shoe mass (Table 1), we expect the same relationship between metabolic cost differences and performance time. Whether these differences can be extrapolated through a full marathon remains to be determined, but even small percent differences in performance times can be very meaningful to the runners.

So they think it's actually close to 2.7%?

Interesting choices, they only took guys who could run sub-32 and who hadn't been injured recently. They measured both oxygen uptake and kinetics like ground time.

It looks like there really is a range of results from 0 to 6% -- if this isn't noise (maybe one guy has a bad day and another has a good day) then the benefit of the shoe might vary wildly from person to person. But it's worth noting that only one person did worse (only slightly worse) in the 4% than the other shoes, so there really is a big effect overall.

Is it possible that in addition to finding the fastest runners, top level coaches are going to need to start looking for top level shoe-responders? If you're a member of the 0% club are you always going to be slower than the 6% club?

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