I was (and still am) skeptical of this rediculous new record of 2:09:56 by Ruth. Originally, I was set to prove that the record differential is even smaller than road ultramarathons, as people think the difference between men and women shrinks as distance increases for long distance events. But I was actually wrong.
Ruths record of 2:09:56 turns out to be 7.75% slower than Kiptums 2:00:35 (7,796 seconds / 7235s=1.0775)
Now in the 100km distance (roughly 2.5 marathons) the records are
Men: Alexandr Sorokin's record is 6:05:35 and for the women it is Tomoe Abe 6:33:11 which is 7.55% slower. (23,591s/21,935s = 1.0755).
This means that the differential between the mens and womens record is still bigger for the marathon than the 100km race. If the differential were to match the differential at 100km then the womens marathon record would be 2:09:37.
Not sure what this means. Could be irrelevant. I'm obviously not saying they should match. I'm still skeptical, but it is interesting that Ruths time is still slower than the road ultra differentials for men and women.