Tomorrow I have Kaiser planned as my VO2 session which is 6x3 min 120% with 3 min rests between each interval. Last week was Spencer which is nearly the same as Kaiser but one less interval. I struggled to complete Spencer and added a few more minutes of recovery before the last two intervals.

So my question is, is there a variance of adaptation that will occur if I substitute Kaiser for Dade -1 which has 3 sets of 3x2 min 120% with 2 minutes of recovery between intervals, and each set has a 6 minute recovery afterwards. Both workouts have 18 minutes at 120% but one just adds more recovery. Is the variance less than say, a workout with 3 mins at 120% but longer rest between like 4 or 5 minutes?