2+4+2+4+2+4+2+4+2+4+2 = 32 (not 36)
But counting the rest periods seems sort of weird to me. Unless it’s short/ shorts like 30/15’s for example.
i would then say the complete interval duration would “count” as intensity, because in the 15 second rest between the 30 second work repeats you are still at VO2max like breathing and high heartrate.
But for something where you work for 2 minutes and have 4 minutes of rest, counting the rest seems odd.
But meh, wahatever, i don’t bother with counting time at intensity anyway. Training Intensity Distribution (TID) based on # of workouts serves me just fine.
~ 4 endurance workouts + 1 HIT workout = 80/20.
K.I.S.S. 