When Will Men's Marathoners Run Under 2 Hours?

On Twitter, Ive been having an interesting exchange with @Ben_Geman and @skepticalsports (Benjamin Morris of @fivethirtyeight). The topic is if and when men's marathon runners will run under 2 hours.

Currently, the world record is held by Dennis Kimetto of Kenya who ran 2:02:57 in Berlin in 2014. To break 2 hours would require an improivement of 2.5% from this time. That is a big number. I was curious about how quickly improvements in the marathon record of 2.5% have occurred over time. That is shown in the graph above (Data: IAAF and Wikipedia).

The red lines indicate that a new record was set that we 2.5% or more faster than the last time the record was improved by 2.5%. For instance, it took 4,402 days (from March 1935 to April 1947) for the record to improve by 2.5%. Yet, in the subsequent decades the marathon record was broken 5 successive time by at least 2.5% on average every 1,600 days, or every 4.5 years.

Then it took 30 years for it to happen again, from 1969 until 1999. The current record is 2.5% faster than that of 1999, and took 15 years. I can spin a bunch of contradictory narratives from this data!

Via Twitter, Ben Morris offers an interesting and way to focus some attention on this issue.

@RogerPielkeJr @Ben_Geman Friendly O/U bet? You set the year and I'll pick whether to go over or under, laying 105 to your 100. Negotiable.

— Benjamin Morris (@skepticalsports) July 13, 2015

As readers here know, I think that predicting the future is pretty difficult. Even so, it offers a great test of what we think we know and a way to organize that thinking. One of the chapters in The Least Thing, my book on sports, is about the limits of human performance and this appears to make for a great topic to include.

So I am inclined to take Ben up. This post is a starting point for thinking this through.  No conclusions yet, and I'll post up my research/analysis as I go along. It'd be great to canvas some experts on this, like David Epstein and Ross Tucker, and maybe even some elite runners as well.

For more reading on this topic see:

• Joyner et al. 2011: The Two Hour Marathon: Who and When?
• Deadspin: How Close are We to a Two Hour Marathon?
• Ross Tucker: The 2-hour marathon and the 4-min mile
• More Ross Tucker: Is the sub-2 hour marathon imminent? Don’t hold your breath, and here’s why
• David Epstein: TED Talk, Are Athletes Really Getting Faster, Better, Stronger?
• Ed Caesar: Two Hours (forthcoming)