For reference, the Aquathlon nationals last year was a run-swim-run course.. It's a regular venue for a monthly splash n dash (which is just swim-run) here in Austin.
The course was essentially 3+ 1k loops running, then 1000m swim, then just under 3 more 1k loops running (gravel path).
My garmin had 2.04mi as the first run split, and 1.74mi as the second.
The very fastest paces were about 5:30/mi on the first run, 1:14/100m on the swim, then 5:50/mi on the second run, with ~30s transitions. Top overall time was 36:45, with 13 guys 40min flat or better (age range of that group was 14-52!!). Those top paces translate roughly to to ~24:20 on the crossfit distances without any speeding up due to the shorter distances.
I think anyone in that sub-40 group could easily beat the 28min crossfit time, and this wasn't a particularly deep field (I know most of the top local long-course triathletes didn't compete, and really not a huge travel incentive just for aquathlon), and I know that a bunch of us racing weren't in peak shape, we just did the race since it was local.
So, decent triathletes would embarrass the crossfitters at this event, but then how many of them complete the other events? Here's what I found for the 2017 event list:
https://games.crossfit.com/workouts/games/2017 As a former swimmer I still have solid upper body strength, but I sure as shit can't do any 100lb-dumbbell presses, let alone 20 (even though this move is the standing, leg-assist boost type of overhead press).
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