I just listened to this podcast and I think there were so many quotes that were part of the ideology when I first started training. One of the biggest things he mentioned was that intensity should be done only up to the level of the desired adaptation. I think I had suggested the same thing to someone else the other week. I think I haven’t been following my own advice though doing 2 TR interval sessions on the bike and doing a hilly ride on the weekend. I have ended up paying the price for doing some hilly routes riding and running and not mentally logging them as “intensity”.
As far as going above threshold, he didn’t say that they don’t go above threshold, just not above what is appropriate for that particular athlete. So on the swim, that means some sort of repeatability for the swim intervals. He talked about some guys coming in at 1:06 /100m vs 1:10/100m. Both of those paces would be above race pace assuming the only reason they were doing them at 1:10 instead of 1:06 is because they were carrying a lot of fatigue.
Also, these guys are ~30 min 10k runners, so their running race pace is faster than threshold.