Sifan Hassan
Crunching the data suggests that distance runners at this year’s track world champs paced more aggressively than ever. (Photo: Richard Heathcote/Getty)
Sweat Science

The New Culture of Hammering Races Right from the Start

Crunching the data suggests that distance runners at this year’s track world champs paced more aggressively than ever

Sifan Hassan
Richard Heathcote/Getty(Photo)

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In the craziest and most exciting race at the recently concluded IAAF world track and field championships in Doha, one of the contenders threw caution to the wind and decided to hammer right from the start. It’s as if they were channeling the famous (but almost certainly apocryphal) Steve Prefontaine quote: “The only good pace is suicide pace… and today looks like a good day to die.” Except they didn’t die—they kept rolling right to the finish, smashing records and dragging the rest of the field to lifetime bests.

Which race am I talking about? Well, take your pick. It could have been Donovan Brazier in the men’s 800 meters, setting an American and championship record of 1:42.34 after Puerto Rican champion Wesley Vasquez towed the field through the fastest first lap ever recorded in a World Championships. Or Sifan Hassan, leading almost the entire race en route to a 3:51.95 championship record in the women’s 1,500. Or Tim Cheruiyot going wire-to-wire in the men’s 1,500 to notch the first ever sub-3:30 in an unrabbited race. Or the championship records in the women’s 5,000 and steeple, or the sub-13:00 and sub-27:00 clockings in the men’s 5,000 and 10,000 meters. You get the point. It was, an IAAF analysis concluded, “the highest-quality championships of all time.”

Among running fans (at least the ones I hang out with), there was a lot of talk about “the end of the Mo Farah era.” Farah racked up 10 gold medals over 5,000 and 10,000 meters at the Olympics and World Championships between 2011 and 2017, mostly by deploying a lethal finishing kick over the last lap or two. But the winning times were often slow, and Farah was often criticized for never leading races until the finish. Similarly, middle-distance aficionados have bemoaned the rise of sit-and-kick 1,500 races like Matthew Centrowitz’s 2016 Olympic win in a time of 3:50.00, the slowest since 1932.

So did this year really represent some sort of cultural shift away from cautious sit-and-kick racing, or are we just dazzled by a few outlier races? To find out, I decided to plot some data from the last 20 years of world championships (that’s 11 meets, since they’re held every two years), for the men’s and women’s 800, 1500, 5,000, 10,000, and 3,000-meter steeplechase. The data is from; I didn’t go back to earlier years because the data on intermediate splits gets a little patchier.

To quantify how fast the races started, I used two versions of what I call the Kamikaze Index. The Absolute Kamikaze Index (AKI) reflects the speed of the opening section of the race (the first lap for the 800 and 1,500, and the first kilometer for the 5,000, 10,000, and steeple), compared to the respective 2019 race. An AKI greater than zero means the race was faster than this year; an AKI less than zero means it was slower. So if the AKI is +3.0, that means the race started 3.0 percent faster than this year. For example, Tim Cheruyiot’s first lap this year was 55.01 seconds; in 2017, he also led the first lap in 61.63 seconds. His first-lap speed was 10.7 percent slower in 2017 compared to 2019, giving him a 2017 AKI of -10.7.

Here’s the average AKI for the five distance events (note that women’s steeple only started in 2005):


You can see that pretty much all the values are less than zero. The only exception is the women’s races in 2003, highlighted by since-convicted doper Süreyya Ayhan’s brazen 60.50 opener in the 1,500 and Anikó Kàlovics’s 2:59 opening kilometer in the 10,000. Overall, the values are pretty strongly negative from 2005 to 2017, with the men dragging them down the most. Bottom line: yes, this year’s races started considerably faster than recent editions of the championships, though not that much differently from the earlier turn-of-the-century meets.

There’s another way of looking at this, though. One fairly obvious reason that people might start races faster or slower is their overall fitness. Sifan Hassan’s opening lap of 63.53 seconds was pretty bold, and was in fact the second-fastest opening lap in the women’s 1,500 for the years I analyzed. But it was hardly kamikaze: she actually accelerated from that point on, finishing in a massive championship record of 3:51.95. In comparison, Ayhan’s first lap in 2003 came in a 3:58 race, meaning she started far faster than she could sustain.

To account for that difference, I also plotted a Relative Kamikaze Index (RKI) which was scaled to each year’s winning time instead of this year’s opening split. An RKI of +3.0 means your speed in the opening part of the race was 3.0 percent faster than the overall average speed of the entire race; a score of -3.0 means you started 3.0 percent slower than the overall average. Here’s what that data looks like:


Broadly speaking, the AKI and RKI patterns are pretty similar. The RKI numbers are smaller, because we’ve taken out some of the variation that results from stronger or weaker fields in a given year. But we still have values close to zero from 1999 to 2003, then significantly negative values from 2005 to 2017 (meaning slow-starting races) then a return to near-zero (meaning evenly paced) values this year. In fact, the men had a slightly positive average RKI of +0.5 this year—only the second time that’s happened, equalling the +0.5 from 2001. (The women had an average RKI of 0.0 in 2003.) Brazier’s +4.4 led the way.

This data confirms that yes, Doha was different, at least compared to the last decade and a half. But it also suggests that we can’t blame Mo Farah for the epidemic of slow-starting races, because they took hold around 2005. Even if we look exclusively at Farah’s events, we can’t find any evidence that he presided over a uniquely cowardly era. Here are the Kamikaze indices for the men’s 10,000 races:


There were some very bold and fast-starting races in 2007 and 2009, while Farah’s first victory in 2011 started very slowly. But Farah also won some fast-starting races, including the only one with positive KI values, in 2017. This year’s 10,000 was a tour de force, with Ugandan star Joshua Cheptegei pushing a hard pace along with teammate Abdallah Mande and Kenyans Rhonex Kipruto and Rodgers Kwemoi. They hit the first kilometer in 2:43, halfway in 13:33, and Cheptegei finished in 26:48.36. Amazing! Could Farah have handled a hot pace like that and still found his trademark finishing kick?

In a word, yes. Cheptegei also pushed the pace in 2017, with help from Kenyans Bedan Karoki and Geoffrey Kamworor. They hit the first kilometer in 2:39, halfway in 13:33, and Cheptegei finished in 26:49.94. The problem was that Farah finished in front of him. It was a ton of fun to see such fast races this year, and I hope we’ll see many more in the future. But the hallmark of the greatest runners—the ones who win world championships—is that they find a way to win no matter how the race plays out.

My book, Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance, with a foreword by Malcolm Gladwell, is now available. For more, join me on Twitter and Facebook, and sign up for the Sweat Science email newsletter.

Lead Photo: Richard Heathcote/Getty

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