Wired Mag: Legal doping? Were Zoom Vaporfly 4% wearers twice as likely to negative split NYC?

I'm sorry but this proves nothing

Thanks for posting this! I took the elites out for a couple reasons:

1) They have different pacing goals. Because they're trying to win, or get in the top ten, they care more about relative performance and they are more likely to be pacing against the group, not against the clock. The runners in the photos are much more likely to be trying to hit time goals. I figured it would make the data set a bit cleaner to just look at the latter group.

2) The question of whether the shoes help elites is interesting! But I was more interested in the question of whether they help slower folks.

I could though rerun the data pretty easily with them included to see if it shows anything different.

Agreed. It doesn't prove anything. It's just one small sample. But I wrote it up because I thought it was interesting.

How did you pick the 92 people you photographed? I ran solo through the Bronx, had my number and shoes clearly visible but am not in this chart. If your theory is that VaporFlys help you even split... I would not have helped!

They're just the people my friend happened to have photographed. He didn't know that I would end up using the pictures in any way.

OK. Not to completely rain on your parade but I know at least two of the runners shown in your chart as wearing the VaporFlys are wearing red ZoomFlys.

Here is the data:

We wonder why he eliminated the elites (to get rid of DNFS??). We'll ask him and report back.[/quote]

Somebody running in Vaporflys is likely an experienced marathoner, hence the even performances so this negates the accuracy of the test, it is not like for like. There could be a placebo as well. My best guess was that these shoes give 30s of benefit for the marathon distance at best. The new Adidas shoes have not proved any gain yet, in fact the Adios produced numerous 2:02-03 times but Kipsang's best in the Sub2s is 2:04.

#4083 is one of my runners. She had a PR of 5 minutes at NYC....her training parter set a 9+ minute PR at NYC and ran the second half 1 second slower than the first.

She said she had plenty of snap left in her legs and significantly picked up the pace the last 6 miles. Her training partner said that he never struggled, but the pace he maintained was about all he could manage the last 4-5 miles.

I'm a big fan of good cushioned shoes for my marathoners. Although I had no idea either of them were gonna wear these shoes. (They're in Dallas, I'm in San Antonio and don't see them much)

I appreciate the effort, but let's be clear:

Even if the sample size was larger, this proves nothing. The reason is that the people who buy fancy shoes might be very different in many ways from the people with "regular" shoes. Obv, the first thing that comes to mind is how rich they are. But there are other factors, more directly related to the result. What if those who spend a lot on shoes are more obsessed with the perfect marathon, better prepared, and thus run more even splits? It could go the other way round, and there are many other things to consider, but the bottom line is this: the only way to settle this question is to run an experiment, where you randomize who gets to run in fancy shoes and who doesn't.

Abdoujaparov wrote:

OK. Not to completely rain on your parade but I know at least two of the runners shown in your chart as wearing the VaporFlys are wearing red ZoomFlys.

To follow up:

585 - definitely ZoomFlys

2261 - looks very much like ZoomFlys

3132 - definitely ZoomFlys

646 - Nikes but not even from this new range - this one is really random

610 - definitely ZoomFlys

I haven't checked them all but this is some bad science. You should fix or withdraw the article.

The true answer is: no one knows. There are too many confounding factors that weren't eliminated, that couldn't be eliminated, or that no one even tried to eliminate.

When the true answer is "no one knows," suggesting that thee's evidence that the shoes are "legal doping" is just giving Nike free advertising.

OK, I read the article now, and part of that is mentioned. Still, the conclusion is way to strong. Btw, there's an argument to be made that having a slight positive split at the NYC marathon is optimal.

In general, don't go down the rabbit hole of confusing correlation with causation. You might end up as a nutritional scientist, changing your opinion every decade.

Why don't we have someone put on the shoes, hop on a treadmill and take their pulse?

Do same pace the next day in a separate pair of shoes.

RejectRunner wrote:

I'm sorry but this proves nothing

Right on RejectRunner

LetsRun.com wrote:

Why don't we have someone put on the shoes, hop on a treadmill and take their pulse?

Do same pace the next day in a separate pair of shoes.

That's the basic idea behind the running economy tests Nike did on sub-elites which supposedly showed a 4% improvement - i.e. they could run 4% faster with the same oxygen consumption. This does not seem to be happening in races though or we would have seen a legal sub-2 marathon by now.

Hardloper wrote:

LetsRun.com wrote:

Why don't we have someone put on the shoes, hop on a treadmill and take their pulse?

Do same pace the next day in a separate pair of shoes.

That's the basic idea behind the running economy tests Nike did on sub-elites which supposedly showed a 4% improvement - i.e. they could run 4% faster with the same oxygen consumption. This does not seem to be happening in races though or we would have seen a legal sub-2 marathon by now.

Yeah O2 uptake is a better readout, but how about insole-based power measurements? Those have to be the best and don't need gas exchange systems which introduce an uncomfortable confounding variable.

Selection bias: athletes who are more likely to perform better may be more likely to spend more on running shoes. They need to compare avg improvement between nyc and last marathon for runners in the two groups.

I'm usually sore the next day.

I agree 100% with the many posters above saying that this doesn’t prove much... but it is still quite interesting. It’s not a properly controlled study but it is interesting observational data.

The fact that the slowest runner ran 3:15 is alarming though... this definitely only represents a fast cross section of the population who may be more apt to not crash and burn in the marathon.