Non-stop indoor cycling classes

Over the last two weeks I've used two different options for non-stop 55 minute indoor cycling classes. In one, we did nothing but climb the entire time with resistance varying from 5-10 on a scale of 1-10. Resistance on the Keiser bikes on the upper end went from 15-20, maybe 21. With the climbing effort we did mainly seated efforts varying from 10 seconds of mainly anaerobic efforts to longer 3-5 minute efforts at 85-92% of max HR. With the constant high resistance, recovery was limited between intervals. If I remember correctly, average cadence was 92 and average power at 245.

The next week we went with high cadence start to finish with resistance varying from 3-8 on a scale of 1-10 or gears 13-18 on the Keiser. I found this to be more of a challenge than the climbing. The time between intervals was on the easier gear but pushing 115-120 rpms. Like above, we did 10 seconds to 3-5 minute efforts at varying resistances. I the end, average rpms came in at 111 and power at 220. Going to the 55 minute circuit after this was difficult. I was really dragging halfway through that class.