I completed a workout today (San Joaquin +3) comprised of repeated 50-second intervals at 130%, separated by 20-second recoveries. It follows from a similar workout last week (Ansel Adams -2) in which the same work intervals were separated by 50 seconds of recovery. While SJ+3 has 27 work intervals vs 24 for AA-2, I was wondering how different these two workouts could really be. After all, most of what is changing is the spacing of the recoveries.
But check out the PR curve comparing the two workouts. SJ+3(red) and AA-2(blue) have the same 50-second output, which is to be expected since both use 50-second work intervals at 130%. But the shorter recovery of SJ+3 translates to significantly higher sustained work out to about the 5:30 mark (and even beyond that, though the gap is a lot smaller). Goes to show how different the burden can be even for exceedingly similar workouts.