Ineos 1:59 Challenge

Breaking2 was a project run by sports equipment manufacturer Nike announced in December 2016 with the goal of breaking the 2-hour mark over the marathon. Three runners, Zersenay Tadese, Lelisa Desisa, and Eliud Kipchoge were to attempt the feat, assisted by a team of pacemakers, scientists, engineers, physicians and trainers. The world record at the time was held by Dennis Kimeto, set at the 2014 Berlin Marathon where he ran 2:02:57, while Kipchoge, whom Ed Caesar of Wired described as "the best marathoner in the world" had a personal best of 2:03:05.[5] Tadese and Desisa had marathon personal bests of 2:10:41 and 2:04:45, respectively, while Tadese had the fastest half-marathon best of the three at 58:23. The reason for Tadese's selection was his perceived potential based on assessments made by the support team.[6][7]

Nike announced the race would take place at the Monza Circuit near Monza, Italy, where Kipchoge ran a half marathon personal best of 59:17 during a test event.[8] The course was 2.4 kilometres (1.5 mi) long which meant the run would consist of about 17.5 laps around the course.[9]

The attempt took place on 6 May 2017 at 5:45 a.m. Central European Time (UTC+1).[9] Groups of 6 pacemakers ran in a diamond formation around the three runners and aimed to go through every 5 kilometres (3.1 mi) in 14:13. For the first 5-kilometre section split, they were one second off the pace, going through in 14:14, and they later went through the 10 kilometres (6.2 mi) mark in 28:21. Around 50 minutes into the race, Desisa dropped out of the group before Tadese and Kipchoge went together through halfway in 59:57. Tadese soon dropped off the pace leaving Kipchoge alone to pass through 30 kilometres (19 mi) in 1:25:20 and 40 kilometres (25 mi) in 1:54:00. Falling behind the target pace, Kipchoge would need to increase his pace in order to run under 2 hours. However, he lost 10 seconds on the final lap, leaving him short of the goal by 25 seconds in a time of 2:00:25. Tadese finished in 2:06:51 and Desisa in 2:14:10[10][11]

Despite beating Kimetto's record of 2:02:57, Kipchoge's time could not be ratified by the IAAF (now known as World Athletics) as the attempt included the use of interchangeable pacemakers. Caesar believed that factors contributing to the failure of the attempt were the temperature and humidity on the day, which were both higher than the ideal range.[11] A 2012 study found that the ideal temperature was 4 °C (39 °F) and that a 10 °C increase resulted in a 1.4% decrease in speed, while the temperature during the attempt was 11 °C (52 °F).[3]

Later in 2017, Kipchoge competed in the Berlin Marathon alongside the likes of Kenenisa Bekele (the defending champion), Wilson Kipsang, Vincent Kipruto, Guye Adola, Mosinet Geremew, and Felix Kandie. Kipchoge won in a time of 2:03:32, his second fastest time after his 2:03:05 performance at the 2016 London Marathon. The victory marked his 8th win out of the past 9 marathons he had competed in, excluding Breaking2.[12] Kipchoge followed this success with a victory in the 2018 London Marathon. Pacemakers were instructed to and passed through the halfway mark in 1:01:00, faster than the world record pace following splits of 13:48 and 28:19 through 5 kilometres and 10 kilometres, respectively. In the 24th mile, Kipchoge left Ethiopian Shura Kitata to win in a time of 2:04:17.[13] Kipchoge next raced in the 2018 Berlin Marathon held on 16 September 2018. He stated that his preparation was "entirely concentrated" on the race and was "confident" that he could beat his personal best. Also racing were the likes of Tadese and Kipsang.[14] Kipchoge completed the first 10 kilometres in 29:01 and the second in 28:55 before passing through the halfway mark in 61:06 before the last pacemaker soon dropped out. He then ran solo for the rest of the race, running a negative split and a 60:34 second half. He crossed the line in a world record time of 2:01:39, 78 seconds faster than Kimeto's previous world record.[15][16] He next raced in the 2019 London Marathon in April 2019. A group of nine went through 10 kilometres (6.2 mi) in 29:01 and halfway in 61:37 before Kipchoge increased the pace and "one by one" his competitors dropped out of the group. Through the 24th mile, only Geremew managed to stay with him. Kipchoge ran the next two miles in 4:26 and 4:30 to win the race 2:02:37, while Geremew finished second in 2:02:55. This was Kipchoge's second fastest time behind his Berlin world record and also the second fastest marathon in history as well as his fourth London Marathon victory.[17]

The attempt was to take place in the Prater, a park in Vienna, Austria. The city was chosen to host the run after an "extensive search of venues fitting Eliud's criteria" with factors such as time zone, weather, and number of spectators considered.[21] A preprint published in October 2019 claimed that the oxygen uptake on the Vienna course would "fluctuate by no more than 2% of the oxygen uptake rates on a flat, straight course" and that it would "incur a penalty of less than 5 seconds compared to a perfectly level and straight course".[22]

Comparison of Kipchoge's speeds in Breaking2, the 2018 Berlin Marathon world record, and the Ineos 1:59 Challenge.[23]

For the attempt Kipchoge was joined by forty-one pacemakers,[24] who rotated twice each lap and ran in a V-formation, rather than the diamond formation chosen for the previous attempt. Kipchoge was placed at the bottom of the formation with two pacemakers running behind him.[25] Each lap of the course featured two 4.3-kilometre (2.7-mile) out-and-back stretches of Hauptallee with the turning points coming at the Lusthaus and Praterstern roundabouts at either end of the avenue, in the Prater park. The entire route inclines only 2.4 metres (7.9 feet). Spectators were present for the attempt.[26]

The organizers planned to run the event on Saturday, 12 October 2019, but they had a reserve window of eight days in case of poor weather conditions.[27] The attempt was run on 12 October starting at 08:15 CET. Organizers allowed a start time between 05:00 and 09:00, but chose 08:15 to maximize viewership. The weather conditions were expected to be dry with a temperature of 9 °C (48 °F) at the start, rising to 12 °C (54 °F) at the finish.[28]

Kipchoge completed the challenge with an official time of 1:59:40.2, an average speed of 5.88 metres per second (21.2 km/h; 13.2 mph).[31] Directly after finishing the run, Kipchoge stated: "I am feeling good. After Roger Bannister in 1954 it took another 63 years, I tried and I did not get it - 65 years, I am the first man - I want to inspire many people, that no human is limited."[32]