BLIF: when doing VO2 Max workouts, do I go all out for the full duration or slowly build through zone 3 and 4 before hitting zone 5 at some point mid workout? Context: I’m proud to report. I have religiously been doing zone 5/ VO2 max training weekly at Peter’s recommendation. I have been doing five reps of three or four minutes each sprinting up a hill. Each rep, I sprint out of the gate and immediately get into zone 5 and stay there for the duration of the three or four minutes. Of course, I am slowing down significantly by the end, but staying in zone 5. Is that the correct protocol? I ask because I thought I recall Peter saying you shouldn’t hit zone 5 or your max heart rate until a minute or two in.