Wore vapor flys for 5k today and pred by 1 minute.

Lets Do This Idea wrote:

I'd be interested in seeing Ward's paper. I'll have to look it up.

But also, shhhh, we're trying to gain momentum here to have letsrun pay for a bunch of shoes for slouches to race in for science.

Oh shiz whoops. Sorry about that.

HEY LETSRUN! WE HAVE AN IDEA!

Lets Do This Idea wrote:

I'd be interested in seeing Ward's paper. I'll have to look it up.

But also, shhhh, we're trying to gain momentum here to have letsrun pay for a bunch of shoes for slouches to race in for science.

His conclusion was that yes, the VF did improve running economy. But, ultimately, whichever shoe feels the best and makes you feel the most confident, will yield the best results.

Very likely the case here. The OP went out hard and believed he was able to run that fast (due to shoes, whatever), so he did.

vaporflys allow you to easier run at faster speeds, but that is not to say that it is a speed shoe. this is why it's not recommended for the 5k/10k among pros because they can maintain pretty high speeds throughout the race. to the slower runners that go 20 minute or slower per 5k because 20 minutes is a pretty slow pace and the vaporfly will make this pace easier for you

Let me ask you:

Did anything in your training changed during the weeks leading to your 5k PR, or was the same?

As mentioned by a couple of individuals, an improvement in running economy of 4% doesn't necessarily translate into a 4% time improvement. It has then been suggested that we do a bunch of time-trials/races to see what the difference is. The problem with this is the number of uncontrollable variables that influence your performance time. Over 10-k, just the day-to-day performance differences are pretty wide and that ends up as a statistically non-significant finding. You can't do this kind of study with only 10-15 subjects, you'd need 100 subjects. The cost to do this type of study gets out of control. Hence the reason it has not been done.

One factor that I have heard little about with respect to the vaporfly is the leg muscle fatigue issue. the shoes may not have a significant (measurable) impact in the early part of a race; however, if it reduces cumulative fatigue, this may be highly significant after 2-3 hours (EMG work would get at this question). Another factor is the use of these shoes in training. Does it reduce fatigue on a day-to-day basis thereby allowing the muscles to recover quicker so that the overall quality of training is better? Prevention of injuries... Of course $250-350 for a pair of training shoes each 1-2 weeks isn't reasonable if you are putting in 100 mpw, but for those getting shoes for free, why not train in them?

So, assuming the IAAF bans the shoes in competition, are they also going to ban them from use in training?

BTW - I direct a Human Performance lab, so if anyone has some good ideas for research, send them my way.

I think that training in them could be the ultimate cross-training tool: almost identical movement with a much reduced impact. For sure Nike's elite athletes are training in them, and it may give them an additional edge over those who train in other brands but race in VF.

Hysteria about these shoes is so high that nobody even bothered to rate this troll.

The NYT/Strava study is pretty much the end of this discussion:

They're faster, and it almost doesn't matter why (lighter shoe, less muscle fatigue during the race, the carbon plate). It is likely a safe assumption that this benefit is not related to use of VFs for training, because likely no one does this to an extent that it would make a difference (and you also make several assumptions about this that don't have backing). And as the study states, runners of all levels saw a time benefit in the VF.

Assuming that all of the other major shoes companies will also come out with next-gen marathon shoes (lighter, cushion-y, plate or no plate) in the next couple years, and assuming widespread adoption of these next-gen shoes (both safe assumptions), there will be a lot more interesting data and the possibility to isolate the effect of the plate, stack height, etc. across brands/designs/approaches. Currently, at least at the elite level, comparisons are difficult b/c the overwhelming majority of elites are wearing the VFs. This could/should change in the future, at least to reflect previous distributions of, say, Adidas vs. Nike athletes (as Nike has always been bigger).

Most of the studies completed have too many variables to be able to say definitively whether the Vaporfly actually makes a difference. The only conclusive way to determine the faster shoe is to race with Vaporfly on your left foot and Adizero Adios on your right, and see which foot crosses the line first.

Roger Barrister wrote:

Most of the studies completed have too many variables to be able to say definitively whether the Vaporfly actually makes a difference. The only conclusive way to determine the faster shoe is to race with Vaporfly on your left foot and Adizero Adios on your right, and see which foot crosses the line first.

Re-read the earlier comments by "Do The Test" and "interesting!".

Comparing Vaporflys against other shoes does introduce too many variables but these guys are talking about similar Nike shoes with / without the carbon Plate. And it's not even using Vaporflys, just looking at the plate.

Think this would be a good test.

I’d be highly surprised if Nike doesn’t already have these data (same shoe with or without the plate),

Roger Barrister wrote:

Most of the studies completed have too many variables to be able to say definitively whether the Vaporfly actually makes a difference. The only conclusive way to determine the faster shoe is to race with Vaporfly on your left foot and Adizero Adios on your right, and see which foot crosses the line first.

Once you determine the faster shoe, wear that one on your right foot and the slower one on the left, and you will be ready for your next track race (being careful on the straights to not step on the infield)

Keep the sport clean wrote:

While you're at it might as well go to the anti aging clinics and get some Androgel.

I heard from a reliable source that it's for heart problems.

Ughh for the 100th time. I've had these shoes since 2017. I set PRs. Then I had these shoes in 2018 and 2019 I STILL set PRs.

How can I keep setting PRs if its the shoes?

I am Kickapoo and I approve this message:

Tell it to:

James Lightbody, Bill Bontron, Peter Snell, Jack Lovelock, Mel Sheppard, Jim Ryun, Marty Liquori

Roger Bannister, Steve Prefontaine, Craig Virgin, Hicham El Guerrouj, Haile Geberselassie,

Paula Radcliffe, Mary Decker Tabb Slaney,

Walter George, Alfred Shrubb, Vladimir Kuts, Gunder Hagg, Emil Zatopek, Henry Rono,

Jesse Owens, Michael Johnson, Lee Evans, Tommie C. Smith, Sebastian Coe, Ron Clarke, Billy Mills,

Eamonn Coglan, Rod Dixon, Dick Quax, Arthur Lydiard, Bill Dellinger.

Yes, most of the above are dead.

However how about people like me who ran 90 miles a week, thru all kinds of upper midwest winter for

entire careers. Yet could not break 4 minutes for 1500 meters. How about all of us?

TELL US SHOE TECHNOLOGY DOES NOT MATTER.

You can use the electro trampolines in meaningless fun runs but honest times should matter.

A world record should be a world record.

To allow this travesty is to ruin cross country, road racing, and most importantly track & field.

You are wrecking it for writers, announcers, but most importantly the Pioneers of the sport.

It's like saying Babe Ruth was never born.

oregon oldtimer wrote:

I’d be highly surprised if Nike doesn’t already have these data (same shoe with or without the plate),

The VF without the plate is essentially the Zoom Pegasus Turbo - which is almost as light as the VF 4%.

The VF is extremely light for the amount of cushioning it has - 6.9 oz (vs 8.1 oz for an Adios Boost).

I find the Pegasus Turbo too squishy and unresponsive - the "feel" just isn't there. The VF's stiffening plate makes a world of difference IMO.

That's a short minute and it's pr'd.

To do a proper test, some things need to be controlled. The two similar weight and cushion shoes with and without carbon plate is a good comparison. Now you need to control the Heart Rate (effort) and cadence. That will tell you if the shoes make a longer stride.

It is best to do something long enough to see the benefit like a 5K at anaerobic threshold pace and do both shoes the same day. Same day factors out feeling good one day vs another and weather, etc. Swap the order and repeat several times on different days. Do this will 100s of runners. Now you get a decent bit of data for comparison.

But seriously, the results already speak for themselves. People have noted studies, Strava data, and just look at the all time top 10 marathon list. To say they are useless is ignoring the data. Were dirt tracks faster than mondo? NO! So why is evolving shoe technology causing speed improvements so hard to believe?

ScientificControl wrote:

To do a proper test, some things need to be controlled. The two similar weight and cushion shoes with and without carbon plate is a good comparison. Now you need to control the Heart Rate (effort) and cadence. That will tell you if the shoes make a longer stride.

Here is my data from two 1 mile time trials earlier this year, same loop course. Temperature and humidity equivalent was within 1 degree Celsius for the two runs. Windspeed difference was 9 kph (or roughly 5.6 mph) between the two days but wind direction was identical.

June 9th - Saucony Type A8

Time: 6:18

Distance: 1.61 km

Avg HR: 162 bpm

Avg stride length: 1.38 metres

Avg cadence: 183 spm

Avg contact time: 229.9 ms

Avg vertical oscillation: 7.3 cms

Avg temperature: 26.6 deg C

Wind: 4 km/hr

June 24th - Nike Vaporfly 4%

Time: 6:18

Distance: 1.61 km

Avg HR: 165 bpm

Avg stride length: 1.40 metres

Avg cadence: 183 spm

Avg contact time: 227.0 ms

Avg vertical oscillation: 7.4 cms

Avg temperature 26.3 deg C

Wind: 13 km/hr

The difference in stride length can be within the rounding error of my watch (a Garmin Fenix 5). The difference in HR was undoubtedly partly the higher windspeed on the second day.

I have also raced 5 kms in Vaporflys - marginal speed improvement over my Adizero Boston 6s or Kinvara 9s that I "usually" wear (I do at most two or three 5k's a year). My recent 5 km PR was in VFs but it was by 9 seconds better than my previous PR (in 2017) and this year's race day conditions were excellent (1 deg C and light wind vs 13.9 deg C and light wind for my previous PR). In those two races, the difference in stride length was 1.27 metres vs 1.29 in the VFs and HR was identical.

That being said, I'm not a speed demon and I don't gravitate to shorter distances but as an average runner/hobbyjogger, I do not see the benefits of the vaporflys for shorter distances. Nope - my conclusion is that VFs are amazing marathon shoes but the magic to them is that they are also very decent racing shoes for shorter distances given their light weight. I will also say that my Saucony A8's "feel" faster in my shorter time trials and I feel more in touch with the ground - they aren't faster as it turns out but I prefer them for shorter distances.