23-Apr-2017 – London Marathon – 2:17:01 – Adidas Takumi Sen Boost 3
Date of birth: 18-Jan-1982
Nationality: Kenyan
Women-Only World Record duration: 6 years, 11 months, 29 days
The athlete:
Coming into the 2017 London Marathon, Mary Keitany had already won the London Marathon twice and the New York City Marathon three times between her debut at the distance in 2010. She had also set the women’s half-marathon world record in 2011 alongside other major half-marathon wins.
She erupted from the start, dropping all but one of the pacers (Caroline Chepkoech) by the third mile. Her pace at 10 kilometres put her on track for an under 2:11 finishing time, the 31:17 split only one second off Chepkoech’s PR at the distance. While slowing slightly, Keitany still passed halfway in 1:06:54, which was at the time the fastest split ever by a woman in a marathon race. For comparison, when Radcliffe won the 2003 London Marathon her split by halfway was 1:08:02.
At 30 kilometres Keitany continued to slow, however she was still 30 seconds ahead of Radcliffe at that same point from her 2003 win. It was only at the 21st mile that she finally dropped outside of world record pace, fatigue starting to take its toll. Rallying in the last few miles, Keitany went under five minutes for her final mile and finished in 2:17:01. Although missing out on the outright women’s marathon world record, she now held the women’s only marathon world record.
Just like Radcliffe had for the 2003 London Marathon, Keitany requested male pacers for the 2018 London Marathon in the hopes of breaking the outright women’s marathon world record. While she was on pace to achieve this for much of the race, unusually hot conditions meant she would fade to fifth by the end of the race.
She would nonetheless still set her half-marathon personal best that year with 1:04:55 which at the time was only four seconds away from the world record. After suffering an injury to her hip during the 2019 London Marathon, Keitany would eventually decide to retire in 2021, having left behind her an incredible legacy.
The shoes:
Hitoshi Mimura had established his credentials at ASICS, having designed shoes for legends like Naoko Takahashi and Mizuki Noguchi as well as having helped develop many other models for the brand. His hiring by Adidas was met with some fanfare, the German company hosting a special press conference to announce the news.
His first project for Adidas was the Takumi Sen, the name roughly translating into ‘An Artisan of The Highest Order’. It was designed for elite runners, following the traditional formula of minimal weight and low profile cushioning. The model continued to evolve, until the third iteration which introduced Boost cushioning to the forefoot. Boost the latest innovation by Adidas at the time, using thermoplastic polyurethane expanded around air pockets to create foam far more responsive and durable than Ethylene Vinyl Acetate or EVA.
It made the shoe somewhat less aggressive than previous versions, however the more responsive cushioning made the model quite popular with elite athletes outside of Japan as well.
References:
https://miffa.cloud/when-adidas-japan-hired-hitoshi-mimura-takumi-sen-ren-saga/
https://www.doctorsofrunning.com/2015/04/adidas-takumi-sen-3-review.html
https://worldathletics.org/news/news/mary-keitany-kenya-half-marathon-retires
https://www.letsrun.com/news/2017/04/london-marathon-flash-results-mary-keitany-runs-21701-take-paula-radcliffes-women-world-record/
https://en.m.wikipedia.org/wiki/Mary_Jepkosgei_Keitany
https://worldathletics.org/heritage/news/london-marathon-2017-keitany-world-record
https://www.runnersworld.com/news/a20865373/mary-keitany-targeting-a-world-record-in-london/
https://en.m.wikipedia.org/wiki/2018_London_Marathon