Kenyan Dennis Kimetto shattered the world marathon record over the weekend, completing a flat Berlin course in idyllic conditions in 2:02:57. He’s the first person ever to run the 26.2-mile distance in under 2:03.
Kimetto’s record time isn’t the only evidence that marathoners are getting faster. Emmanuel Mutai, who came in second to Kimetto in Berlin, also finished ahead of the previous world record marathon time, set a year earlier. New course records in Chicago and London have been set in the last year.
After the race, Kimetto told reporters he thinks he can run even faster. There’s no reason to doubt him, or any of the others who have been mounting the assault on the world record in recent years. The question is just how much faster they can go.
After Sunday’s race in Berlin, the runner-up Mutai was asked if running a sub-two hour marathon would someday be possible.
“From what I saw today, times are coming down and down,’’ Mutai told reporters. “So if not today, then tomorrow. Maybe next time we’ll get 2:01.’’
Running faster is about two things, says Daniel Lieberman, professor in the Department of Human Evolutionary Biology at Harvard University.
“Most of these guys, their aerobic capactity is astonishing,’’ says Lieberman. “They’re not running out of energy. Their problem is the efficiency to deliver that energy.’’
Lieberman is an expert on the biomechanics of endurance running, studying foot strike patterns in barefoot runners vs. those with shoes. Elite and novice runners alike can greatly improve their speed by improving their efficiency.
“If you’ve ever watched these elite runners up close, they’re landing ever so beautifully, on the balls of their feet, with their ankles below their hips. They’re landing really gently and flat. As the body hits the ground, there’s no collision. You can see it in the way they’re kicking.’’
Minor tweaks in technique can account for incremental increases in speed, says Lieberman, but they don’t explain how someone can cut the record time down closer to two hours.
“[Kimetto] basically was running one second faster per mile than the previous fastest world record,’’ says Lieberman. “That’s like a step or two. … Some people believe the curve is asymptoting out and flattening, and some people think there’s a long way to go.’’
In 1991, the Mayo Clinic’s Michael Joyner published a paper in the Journal of Applied Physiology in which he found it was physiologically possible for human being to run a marathon in 1:57:48. A follow up paper predicted it would happen within 12 to 25 years. (h/t Washington Post) Joyner based his findings on an the rise in popularity of marathon running and the expanding gene pool from which the best runners would be plucked. Improvements in nutrition, and in the understanding and harnessing of the efficiency described by Lieberman, also play a factor.
Kimetto has a long way to go. To break two hours, he’ll need to improve his mile time by six seconds. As Roger Robinson writes in Runner’s World, Kimetto’s “4:41.5 pace for 26.2 miles is really not so very close to 4:35 pace, not for those who know what such a pace feels like, not at marathon distance. Road runners at any level know how hard it is to run 6 seconds per mile faster. Track runners know how big a step 1.5 seconds a lap is even for twelve laps, or 25. Try it for 105 laps, cutting from an already peak pace.’’
Kimetto may set another world record or two before he’s done, but the takeaway here is that expecting a sub-two hour marathon from him is unlikely. Whether someone else is capable of it is a question we can’t yet answer. In a recent blog post Joyner cites things that race promoters, shoe companies, and wealthy investors can do to make the two-hour marathon more feasible. It will take a combination of all these things to make it happen.