Dr. Michael Joyner

Well, it was certainly something that had been a long time coming, and we knew that it was sort of physiologically possible when the great Eliot Kivchoge ran 15940 in a special exhibition that was set up in the fall of 2019.

And he had come pretty close in May of

of 2017 so people knew it was uh possible perhaps the times had been drifting down and getting faster and faster in real races as opposed to the exhibitions kipchoge ran so for somebody like me who'd been following it for a long time it was a matter of when not if

It is, but people have taken bites out of the marathon world record similar to that a number of times.

You know, I think Derek Clayton, when he was the first person, the Australian Derek Clayton, when he was one of the first people to break 210, I think his fastest time took a pretty big bite out of the marathon when he went 208.33, I think, in comparison to what other runners had done.

And so I think there have been pretty big bites over the years.

So the idea was, in the 1970s and 1980s, ideas about...

the physiology of endurance sports, and especially distance running, and to some extent cycling, really came into focus.

There started to be really good data on a number of elite athletes at the time, like Derek Clayton, for example.

And we knew

what their maximal oxygen consumption is, or VO2 max, which is sort of the upper limit of aerobic function, we began to understand something called the lactate threshold, which is the percent of their VO2 max that they can sustain for a couple of hours.

And then the question is, is how much speed could they generate?

Some people are more efficient than other people.

And so I simply said, if the same athlete...

had the best value ever reported for all three of those variables, how fast would they go, and came up with a time in the high 158s if that happened.

I pointed out that this model was based on lab data.

Who knows what happened in the real world?

Who knows what would happen to some of these variables over a couple of hours of running?

Who knows how they'd be affected by the heat and things like that?

But at least it seemed like it was in the ballpark.