Date: Saturday, 15 April 2017
Two minutes and 57 seconds — it doesn't sound like much but when it's the last two minutes and 57 seconds of a 42.195-kilometre run, it feels far longer.
It's also the time that needs to be slashed off the current marathon world record to break the elusive "two-hour marathon" barrier.
But let's get one thing straight — it's not going to be easy.
The current record of 2:02:57 was set by Dennis Kimetto of Kenya in 2014.
In 2013, his countryman Wilson Kipsang ran 2:03:23, and in 2011 Patrick Makau ran 2:03:38.
So, although the times are coming down, they are coming down slowly and some scientists believe we may have almost reached the limits of human capability.
Kimetto's world record was run at a blistering two minutes and 56 seconds per kilometre — but to hit 1:59:59 that pace would have to increase to 2:52 a kilometre.
To a recreational runner, knocking four seconds off a kilometre may not sound like too much of a stretch but for a professional, already bolstered by the best of what training, science, and talent can offer, it is a staggering suggestion.
Dick Telford from the University of Canberra's Research Institute for Sport and Exercise believes we will see the barrier broken but says it is near impossible to put a number on when that might be.
He says it "wouldn't be outlandish" to suggest it could fall within the next decade.
But that is not soon enough for some.
In December, Nike announced its Breaking2 project, "a diverse team of leaders across several fields of science and sport" working towards enabling a sub-two-hour marathon, with an attempt at the distance to be held in Monza, Italy, between May 6 and 8 this year.
Adidas also reportedly has a project underway, as does Sub2Hrs, a project led by UK-based sports psychologist Yannis Pitsiladis.
Wouter Hoogkamer and Rodger Kram, of the University of Colorado's Department of Integrative Physiology, and Christopher Arellano, of the University of Houston's Department of Health and Human Performance, recently published a study arguing the two-hour mark could be broken right now under the right conditions.
But what will it actually take to get there?
Interest has swirled around the two-hour marathon mark for some time, but since Kimetto broke 2:03 in 2014 the idea has seemingly become more tangible.
Sports scientist and high-performance coach Kurt Vogel says: "We have a fascination with trying to break barriers, particularly ones that have been standing for quite a long time."
Professor Kram adds, despite being completely arbitrary, the two-hour marathon mark has captured the imagination of athletes, scientists, and the wider community — in much the same way as the four-minute mile captivated the public in the early 1950s.
"Most recreational marathon runners have a goal of breaking three hours — you have to train a lot to break three hours — and a lot of people just want to finish, or do four hours," he said.
"There are people who train really hard who run half as fast as what we're talking about ... running two hours is just an unbelievably extreme goal.
"To knock three minutes off the world record — that's audacious and it gets people's attention ... people say, 'you're crazy', and it's a nice challenge."
In its bid to break two hours, Nike has recruited three elite athletes — Eliud Kipchoge of Kenya, Lelisa Desisa of Ethiopia and Zersenay Tadese of Eritrea.
Kipchoge won the marathon at the 2016 Rio Olympics and has a personal best of 2:03:05.
Tadese currently holds the men's half-marathon world record — a time of 58:23 — and has run a 2:10:41 marathon, while Desisa has a marathon best of 2:04:45.
As Dr Telford says: "We've got an evolution of marathon runners now who are not just long distance runners who go out and do long miles — they're very, very fast."
The trio will skip the traditional major marathons in 2017 and instead participate in Nike's attempt to break the record.
Although Adidas has remained sketchy on the details of its sub-two-hour goals, the company has been the sponsor of Kimetto and the previous three world record holders — Wilson Kipsang, Patrick Makau, and Haile Gebrselassie.
It's all about timing.
"As much as you have the athlete that can perform well, you've got all these other factors which will include the temperature — the athlete's body and core temperature — the humidity, the altitude as well," Vogel said.
Dr Hoogkamer, Professor Kram and Professor Arellano put particular emphasis in their study on the course — specifically the ideas of running downhill and running with a tailwind.
"Our lab has been studying what parts of running cost energy, so we tried to look at the things that are most important — and the things that you can change in a marathon," Dr Hoogkamer said.
"Obviously running downhill is going to be easier but we calculated if we take the downhill allowable by the IAAF [International Association of Athletics Federation] regulations and not go any steeper, we can save 30 seconds [across the second half of the marathon].
"The total distance between start and finish can only be a half marathon, basically, so what we did is we first run a half marathon in loop, then the other half to run downhill and use the tailwind."
The benefit a tailwind could potentially provide is "almost unlimited", Professor Kram says, but to save three minutes Dr Hoogkamer says "you need a wind that basically has the same velocity as the speed you're running".
"If you're running at 21 kilometres per hour, which they're doing, a 21km/h tailwind would save you three minutes," he said.
Nike has not chosen a course as extreme as the one the researchers suggest, instead selecting a Formula One circuit in Monza, Italy as the setting for its marathon attempt.
A Nike spokesman told the Guardian that although the attempt would not be an officially sanctioned world record, the course would be IAAF ratified.
"[It] will meet to all marathon course requirements, including independently measured course distance, start versus finish location and course elevation," the spokesperson told the Guardian.
The looped course will not utilise the benefits of the downhill or tailwind, but it was chosen with a number of factors in mind — climate, terrain, surface and altitude among them.
The timing of the race has been just as carefully selected, based on factors including expected temperature and humidity, and a window of three possible days to allow for unexpected weather or wind conditions.
"I think that people are starting to pay more attention to the course design for a fast time and what we showed is that can make a big difference," Professor Kram said.
But one technique Nike has used that Dr Hoogkamer, Professor Arellano and Professor Kram (who has worked as a paid consultant for Nike, separately to this study) suggest is drafting.
In early March, Nike's athletes ran a practice half marathon with the aid of a contingent of pacers, and two runners, Kipchoge and Tadese, finished under the goal time of 60 minutes.
"We talk about this idea of co-operative drafting ... [four runners] would be running on a single file line, one behind the other and the lead runner will alternate with the other runners," Professor Arellano said.
After three minutes at the front, the lead runner would switch to the back of the line and the second runner would take the lead, and so on, at three minute intervals.
Professor Kram adds: "The runner who's leading is actually pushing it a little above their red line for three minutes, but then they can jump in the back and they can recover for nine minutes."
The team calculated that this technique could save up to 184 seconds — just over three minutes.
Co-operative drafting could be a worthy alternative to finding a course with a tailwind — the researchers note it's not possible to fully benefit from both techniques at the same time.
IAAF rules prohibit pacers joining in halfway, so most attempts at a record have seen pacers drop off by a certain point, leaving the athlete running alone for the last portion of the race — but co-operative drafting would see the benefits extend the entire distance.
And Professor Kram also notes that if the very best runners worked together the time may come down sooner, but athletes are often competing for their sponsors as well as themselves — meaning it is unlikely we will see Adidas athletes banding together with the Nike team.
"It's not like everybody hugs after the race," he said.
Dr Hoogkamer led a study in 2016 that found for each 100 grams of weight added to a shoe, a runner's energy costs rose by about 1 per cent — equal to about one minute across the marathon.
Although the study specified "lighter is not always better" due to a lack of cushioning in super-light shoes, the shoes worn by Kimetto when he set the world record weighed 244 grams.
Dr Hoogkamer, Professor Kram and Professor Arellano believe a pair of 144-gram shoes could be designed without compromising cushioning — and that 100 grams, they say, could take a minute off the time.
In fact, Adidas has already developed a shoe 100 grams lighter than their previous best, which Wilson Kipsang debuted at the Tokyo Marathon in February.
But although he won the race, he *only* ran a time of 2:03:58.
Nike also developed a new pair of shoes specifically for its Breaking2 project and recruited Professor Kram and Dr Hoogkamer to measure the shoe's advantage.
That study has not yet been published but the company claims the shoes will make any runner 4 per cent faster, thanks to its lightweight design, stacked heel, and a stiff carbon fibre plate designed to "propel" runners forward with each step.
IAAF rules around shoes are ambiguous but Nike's senior director for global running footwear, Bret Schoolmeester, has told the New York Times: "We're very confident we're doing things within the rules and above board."
Not everyone is convinced though.
Writing for Runner's World, Alex Hutchinson says: "If the shoe delivers anything close to its promised 4-per cent boost, then it's effectively picking winners and losers — an outcome that clashes with the ideal of running as a simple, stripped-down contest between athletes rather than scientists."
The efforts by Nike and the methods suggested by Dr Hoogkamer, Professor Kram and Professor Arellano demonstrate just how refined the science has become in the bid to break two hours.
But as the discussion around Nike's shoes has demonstrated, there is some contention around how far is too far, in terms of crossing the line towards unnatural performance enhancing.
"There's a certain limit in regards to what is considered natural and what is considered supernatural, or performance-enhancing," Vogel said.
But Professor Kram is unapologetic: "This is performance enhancing."
"We're trying to enhance performance — but not by taking drugs," he said, and indeed, the methods he and his team have put forward are all within the limits of IAAF regulations.
Although recreational runners may seek out the most scenic or interesting course for a marathon, for this team it is a numbers game.
"We appreciate that there's a history to the marathon and ... there's tradition in the marathon and this is violating all that tradition — we're just playing around with numbers," Professor Kram said.
Just say the two-hour marathon barrier does fall — what comes next?
World records have been falling for as long as they have been recorded, but it seems only logical this will eventually stop happening.
Vogel said pinpointing the moment when records flat-line was impossible — but it was likely to, eventually.
He says it's science and technology that has allowed us to move forward in such leaps and bounds.
"If you look at how far we've come in 100 years, funnily enough, it's only science that has helped change it, and technology is the only thing that's really enhanced it to the point where we break records so much," he said.
But Dr Telford disagrees.
He says the continued increase in human population and advances in science mean it is unlikely we will ever reach a point of "feeling it's never going to be overtaken".
"An asymptote is a line approaching another line [but] it never gets to it — we could talk about an asymptotic effect in human performance," Dr Telford said.
The fact that two of the three current projects to break two hours are led by athletic companies leads one to question: Are these attempts simply driven by corporate spin?
Vogel says it certainly plays a large role — as is evident by the fact that both Adidas and Nike have developed models of their high performance shoes that will be available for purchase.
"This is definitely driven by marketing ... if they were genuinely interested in this for the athletes and for the running community then they would join corporate forces to create the best opportunity for the runners to break the record," he said.
Dr Telford says despite the massive amounts of money invested in these attempts, it would be a huge coup for Adidas or Nike to be behind a successful attempt at breaking the barrier.
"Any company associated with the sort of publicity a two-hour marathon would attract has to benefit enormously, especially if their technology is used in the process," he said.
"It's all about corporate interests — but for we coaches and athletes, and for the general public, it's terrific to see these pioneering endeavours, so I'm not critical! We all win."
Ultimately, Vogel says, there is only so much science can control — and everything coming together perfectly at the right time is a supremely difficult thing to achieve.
"Although you've got all the variables right, it still comes down to being able to perform on that day," he said.
"Even though an athlete may peak appropriately, according to science, sometimes it just doesn't work."