The fastest possible marathon
I came across this article in the BBC this morning, which posed the question “when, if ever, will humans run a sub-2-hour marathon?”.
Expert opinion seems to be somewhat divided on this question. The runners themselves seem to think that it’s possible, but not likely within the next few decades. One of the “leading authorities on marathon running in the US” says that it isn’t, while a kinesiology professor from the University of Montreal used some extrapolation formula to predict that the 2 hour mark will be broken in 2028. Just about everyone seemed to agree that 2 hours, 2 minutes is within reach (the current world record stands at 2:03:59).
I’m certainly no expert on distance running, but I did develop something of a method for addressing this question that I used to predict the “fastest possible mile” time (3 minutes, 39 seconds by my estimation).
So I decided to apply the same method here. My conclusion, surprisingly, is that even a marathon time of 2 hours, 2 minutes is far from given. In fact, my prediction is that the “fastest possible marathon” is 2:02:43, only 76 seconds faster than the current world record.
Below I quickly repeat the arguments/procedure I used for the mile and I show the graphical results. (Warning: If you haven’t read my earlier post, the following might not make very much sense).
Here is the progression of the marathon world record over the past 100 years (data from Wikipedia):
If the marathon world record is plotted as a function of “person-years” since 1908, when the world record was first kept, it shows a pretty convincing exponential decay to a particular value: 2:02:43.
Translated back into real time, the progression of the world record marathon time looks like this:
It’s not a rock-solid analysis, but I think the data is actually pretty convincing.
So count me among those who are skeptical that a 2 hour marathon is possible. In fact, count me among that rare (nonexistent?) group of people who are skeptical that a 2 hour, 2 minute marathon is possible.
I hope I’m not right — I love watching humans break records as much as anyone else. But either way, you should take a moment to enjoy watching Haile Gebrselassie’s record-setting performance from 2008. He may have been running to within 1.01% of maximum human capacity.
UPDATE (Sept. 28, 2014): After Dennis Kimetto’s remarkable performance today in Berlin, setting a new world record at 2:02:57, the prediction above is starting to look pretty pessimistic. This data point is way below the trend line in the second plot (by more than a factor 4). Re-doing the same analysis, in fact, gives me an updated projection of 2:01:53 as a “fastest possible marathon time”.
But you can decide for yourself whether that’s worth believing.
UPDATE #2: G&L reader Jens has created a nice infographic showing the time progression of the marathon world record. To me, it sure looks like the men’s time is reaching an asymptote that is above 2 hours.