Maybe Iām abnormal then. 
The workout was definitely not anaerobic, as their was no lactic acid buildup and the intensity was just like Charlie describes it (around 70% of max speed, last rep as fast as first, no muscular fatigue, etc.). BTW: My heart rate was already at 189 after the first 200m, i.e. after the third run in the first set.
What type of heart rates have other members observed during tempo workouts?