Zwift workout last night just took a bit to get "that feeling". What I mean is sometimes your HR is in the floor "this is too easy" but your RPE in the legs is there though.
Was doing 1min/2min stuff. I started out with 2min 97% and 1min at 110%. That was too easy. Next two sets did Zwift % modify in the companion app to get it to 101% and 116%. That worked out just right. It was 9min per set.
I feel under/overs is one of those that has so much variability between how folks do them. Pursuits are just go hammer 5min for four or five times. But I see all manner of different ideas on this one.
I prefer the over/under mentally to just 3x8 or something. Or 2x20. Just keeps your mind busier than blunt force duration/effort.