Science geeks, I'm sure there is some interesting things in the report but I can't help but laugh and say, "Did we really need to do lab tests to tell us Kiphcoge was the best guy for the job or that the best indicator of someon'es marathon potential is how fast someone can run all out for an hour?"
As someone who did find the journal article interesting, a few quick thoughts:
(1) No, there's nothing particularly revolutionary in the study. It's not like "Oh wow, now we know why Kipchoge is fast!" But it's a pretty unique opportunity to see what the physiology of truly elite runners looks like. Back in the 1960s and 1970s, there were studies that included people like Jim Ryun and Frank Shorter and so on, which gave some pretty good insights about the physiology of champions. But there has been very little since then. Lots of studies of "elite" runners, but few of Olympic champions and world-record holders.
(2) One of the big surprises is how low the average VO2max was. Of course everyone knows that there's more to running than VO2max. But if you'd asked me to guess the average VO2max of a bunch of ~60:00 half-marathoners, I would have guessed around 80. That's not an unusual number for top cyclists and XC skiers and even middle-distance runners. Instead, it's 71. That tells us that for half-marathon and up, efficiency and sustainability are wayyyy more important than aerobic capacity. (Yes, yes, we already knew that Frank Shorter was 71.3. But Don Kardong was 77.4, and Pre was 84.4!)
(3) The thing that Rojo mentioned and everyone's jumping all over (critical speed, AKA how fast you can run for an hour, is the best predictor of marathon pace) is a misunderstanding of what they found. You don't measure critical speed by racing for an hour. There are several fairly simple ways you can measure or estimate it, including (as they did in this study) with a sub-maximal lactate test that takes less than 20 minutes and is only hard for the last couple of minutes. This is the approach Jones used to predict (with striking accuracy) all of Paula Radcliffe's marathon times, so it's not new. But once again, it appeared to be pretty accurate for this cohort, which is interesting.
(4) The final surprise was that the average marathon time of the cohort corresponded to about 88% of their VO2max. Back when Michael Joyner wrote the first paper modeling the idea of a sub-2 marathon in 1991, his range of assumptions was that a runner should be able to sustain 75 to 85% of VO2max over the marathon distance. So 85% was considered the upper bound. Recently there have been a few reports of masters runners (like Gene Dykes) sustaining >90% of VO2max for marathons, but they've been controversial. So this estimate of 88% is interesting, because it suggests that what's unique about these particular runners is NOT their VO2max (as noted above), and NOT their running economy (which was good but not unprecedented), but rather their ability to sustain a high percentage of their VO2max for the marathon distance.
I'm sure there are lots of people who will look at those insights and say "Well, duh, I've known that all along." If so, congratulations! But I still find it interesting to see the real-world data. :)