FOR NIKE'S WORLD-CLASS BREAKING2 RESEARCH TEAM, the entire pursuit revolves around one question: How can we help the world’s most elite distance runners be faster—and not just incrementally, but faster than any distance runner ever.

When you’re trying to shave minutes—not seconds—off the world’s fastest times, you need all that science has to offer. Skin temperature monitors and muscle imaging to inform hydration and sugar intake. New types of apparel to help minimise drag. And of course, the Nike Zoom Vaporfly Elite footwear.

To understand how we got here, on the precipice of our historic quest to break the two-hour marathon barrier, we need to start at the beginning.


ATHLETE SELECTION To identify the runners most likely to run under two hours in the marathon, our science team tested many of Nike’s elite distance athletes, measuring three primary factors that help predict performance: Exercise Capacity: an athlete’s maximum capacity for exercise, expressed as VO2 Max, or the maximum rate of oxygen consumed. Running Economy: how much energy a runner needs to run a kilometre at a given speed. Sustainable Velocity: the speed a runner can sustain for a long period of time without needing to slow down. Of the athletes initially screened, three emerged as the most promising: Eliud Kipchoge of Kenya, Lelisa Desisa of Ethiopia and Zersenay Tadese of Eritrea. The testing process yielded key physiological data that allowed our science team to project each athlete’s potential. The team compared each athlete’s personal records against their projections in order to identify areas of focus, and began brainstorming strategies to close these gaps for race day.


For example, while Eliud has refined his hydration techniques over his competitive years, Zersenay, the world-record holder in the half marathon, hydrated minimally. Although Zersenay has incredible running economy, he has the slower marathon personal record of the three athletes, so his hydration is a factor the team has worked to improve. Another example is nutrition strategy. "Marathoners can hit a wall at 30-35k", said Brett Kirby, Lead Physiologist of the NXT Generation Research team in the Nike Sports Research Lab. "This is commonly associated with depletion of their muscle sugars. So how do we keep those sugars up? Maintaining energy levels throughout the marathon could give us another percentage point. We started looking at that and working towards a personalised solution for each athlete".


THE JOURNEY OF RACE DAY OPTIMISATION—FROM SELECTION TO NOW Before the team could work with the athletes to refine their training and conditioning, we needed to understand their current training schedules. In order to do so, our science team met the athletes and their coaches at Nike’s World Headquarters in Beaverton, Oregon. At this first team camp, the science team provided each athlete with GPS watches and heart rate monitors to begin tracking the training load of each athlete. In addition, each athlete was connected to internal Nike performance prediction analysis software. This helped to facilitate individualised athlete learnings, as well as forecast future running performances. Next, the science group teamed up with the product group and went to the athletes’ home training grounds in Kenya, Ethiopia and Spain. They tested and integrated insights across the Nike Breaking2 project, gathered new data and observed first-hand the athletes daily training regimens and lifestyles, constantly looking for avenues where support could be provided. At the first team camp, the science team introduced hydration and nutrition strategies, which have been regularly adjusted month by month. Skin temperatures and sweat rates were monitored. Fit details for the revolutionary Nike Zoom Vaporfly Elite shoe and race day apparel were obsessed over.
And the closer we get to the attempt, the more important temperature becomes for our team.


For the success of Breaking2, the most important temperature reading is the difference between the body’s internal core temperature and skin temperature. This is known as the temperature gradient. "We’re looking at what core body temperature does in relation to skin temperature and we want those two numbers to be as far apart as possible", Brad Wilkins Director of the NXT Generation Research team in the Nike Sports Research Lab said. "That means that the gradient, the temperature gradient, from the core to your skin is really high". In order to maintain a high temperature gradient for each runner, the team is focusing on optimising the environmental conditions for race day. During our half marathon test event, internal and external monitors were used to measure core temperature and skin temperature, respectively. This provided the constant data needed to understand the impact of thermal factors on each athlete’s performance. To try and optimise for temperature, cloud cover and wind, the race will happen over a three-day "launch" window. Over that three-day window, the team will pick the optimal morning for the race. This should maximise the core to skin gradient, allowing for the least impact of thermal factors on the athletes’ performance outcomes. Another important factor that is affected by environment is hydration. Throughout training, the team weighed runners before and after their runs, which tells the team how much water each individual runner has lost through sweat. Then, our team observed how the body of each runner responded to their respective fluid strategies—a carefully crafted sugar-water liquid mixture. This mixture continues to be customised to each athlete’s sweat rate and will evolve as we approach race day.
Other tests, like muscle imaging, showed how much sugar was in the muscle of the athletes. This was crucial, because sugars could help the runners avoid the burnout that is synonymous with the marathon. Or, taking in too much could upset their stomach and throw them off their game.


The next step in race day optimisation brought us to the wooded setting of the Autodromo Nazionale Monza, 13 miles north of Milan for the half marathon simulation. It’s also where we will be for the two-hour marathon attempt. Monza’s flat track with gradual curves, as well as Northern Italy’s temperate climate, make it a good location for the attempt. The half marathon test event was not a race for the athletes to test their fitness. Rather, this was a test of how the Breaking2 team will manage the Breaking2 attempt, logistically. The team asked the athletes to run at a 60-minute half marathon pace. Small alterations, such as Eliud taking a beet root bar with carbohydrates as opposed to beet juice as a pre-run meal, were tested at the trial run. Temperature gradient and, of course, the footwear and apparel were also tested. All of this data has been collected before, but never with athletes of this calibre with the intent of breaking such a barrier. Whether we break the two-hour barrier or not, we’re already in uncharted territory. Territory that can only help all athletes look towards what’s next.


Come race day, we will put everything we’ve learned into practice. We’ll use a dynamic formation with pacers to reduce wind drag for our athletes. We will make sure that the athletes are getting the hydration that’s been perfected for each one of them. And of course, we developed a shoe—the Nike Zoom Vaporfly Elite—designed to turn every advantage into performance. Breaking2 isn’t just a race and it is not an experiment. It’s a model for how much faster we can go when cutting-edge science meets unwavering passion and commitment to the goal. After years of research and development, Breaking2 will debut a system of ground-breaking innovation that has the potential to elevate every runner.