Hi! I was halfway through a VO2 Max workout yesterday and as my legs were feeling more and more heavy a thought occurred to me - does the last interval give you a higher TSS score than the first one where you are fresh and so it’s easier?
If they are all the same intervals, then they all add the same amount to the total TSS.
TSS is IF x 100 / hour.
IF is NP/FTP
TSS isn’t to be confused with physiological cost. It’s a severely limited metric.
If the interval is the same then the TSS accumulated will match. However as @matthiask said, the impact of the later intervals is far greater on your fitness - even if you need to dial those back a bit or take back pedal breaks they will introduce the greatest improvement in fitness.
TSS doesn’t consider fatigue at all. So the last interval is the hardest to do but worth the same TSS. You need to look at the total time spent in the V02 max zone for the workout.