Geoffrey Kamworor split 13:01 from 15k to 20k at the World Half Champs - Valencia 2018

He had a very strong wind on his back during that section, and the race was "slow" until 15km.

If legit, HOLY SH*T!!!!

Don’t think it’s legit. They might’ve had the split mat off by 100-150m. Sure he could run 13:30 with wind on his back but no way he could do 13:01.

The two IAAF measurers checked the course before the start to make sure everything was in the correct place. Very strong winds (gusts of over 45 mph)

Who had the next fastest 15-20km split? Did everyone have a ridiculously fast split?

Next fastest?? wrote:

Who had the next fastest 15-20km split? Did everyone have a ridiculously fast split?

Abraham Naibei Cheroben 13:15, and another 6 seconds back over the final 1.1K

D.Katz wrote:

The two IAAF measurers checked the course before the start to make sure everything was in the correct place. Very strong winds (gusts of over 45 mph)

And was downhill

I think it's legit so I just gave him a splash page.

A few things to consider.

1) The Wr of 58:23 is 13:50 pace so a guy could easily split well under 13:30 in a tactical race.

2) Wind matters A LOT. If it's only worth 6-7 seconds a mile, you are close to 13:00. The win was coming out of the NW. That's basically directly in their backs forr that portion of the course. The course does cut in a little bit but it's probably worth 4km of tail wind for that segment. If the wind is 15 mph, that's a lot. Weather.com says the wind is still 16 mph right now at 8:17 CET so during the race it probably was more. The race broadcast saidi twas at 31 mph when the women started. I don't think it was that high but could believe it was 20 mph.

Back in 2011, BEFORE the Boston Marathon, John Kellogg said that a near 20mph tail wind would be worth 3-4 minutes in a full marathon. So in a half it would be 1.5-2 minutes. Let's split the difference and say it's worth 1:45. Well a 5k is 23.6% of a half so if they had a 20 mph tail wind for the whole 5k it would be 24.8 seconds (.236*1:45 is 24.8 seconds. If we multiply that by .8 (saying they only had a tail wind for 4 of the 5k km) , then you still have a boost of 19.8 seconds.

So could he split a 13:20-25 a get a 20-5 second boost? Yes. I think he just did.

3) The next best split was 13:14. The women's leader split 15:23 during this portion.

You can see the course map in our recap.

http://www.letsrun.com/news/2018/03/geoffrey-kamworor-splits-1301-5k-yes-1301-end-race-win-3rd-straight-world-half-marathon-title/

http://www.letsrun.com/forum/flat_read.php?thread=4006866

Yes I concur with this. All the men ran a crazy 5k split, 13:20 effort from Kamworor to break away would be very doable from a slow start and anyone that was watching could see their shirts rippling in the wind

fyi - I worked the event

It's far easier to imagine that you guys made a mistake than that he ran 13:01 in a half marathon with wind. No one has EVER come close to that in a half marathon in all the races with major wind. Probably off by less than .1M.

We'll have to wait and see Geoff's strava upload. I'm at the edge of my seat.

D.Katz wrote:

fyi - I worked the event

Cool story bro.

All that is true but he is the only one who did it.

Even with the tail gale, he was twenty seconds clear of everyone else.

It is definitely not 13:01 but the way he ran it is what is astounding.

Gudeta was awesome too! Very strong!

Native Son wrote:

It is definitely not 13:01 but the way he ran it is what is astounding.

It was 13:01 from 15 to 20km, and then faster to the finish.

If it was only the wind; why didn't many others finish much faster?

Actually, it was wrote:

Native Son wrote:

It is definitely not 13:01 but the way he ran it is what is astounding.

It was 13:01 from 15 to 20km, and then faster to the finish.

If it was only the wind; why didn't many others finish much faster?

They didn't let loose and go with the flow [of the wind]. If Kamworor ran 13:01 the 2nd place ran 13:20ish. And 13:20 would be ~56:15 pace for a full half.

Run007xx wrote:

D.Katz wrote:

fyi - I worked the event

Cool story bro.

You have no idea who you have just replied to, kid.

Native Son wrote:

All that is true but he is the only one who did it.

Even with the tail gale, he was twenty seconds clear of everyone else.

It is definitely not 13:01 but the way he ran it is what is astounding.

Gudeta was awesome too! Very strong!

Native Son,

I really like your contributions to the forum.

Believe Mr. Katz, his immense experience, and the experience some of us have running in very strong winds.

I truly believe the 13:01

That means from 16k-21k, he most likely split under 13!

Even with the tailwind that's just ridiculous.

sfksbf wrote:

That means from 16k-21k, he most likely split under 13!

Even with the tailwind that's just ridiculous.

Just like the 2011 Boston Marathon Wind Tunnel--15 mph wind speeds.