Originally Posted by PeteHski

From a TSS point of view it is all just fatigue, however you slice it. But I don't believe all units of TSS are equal. I know from my own experience that if I rack up 100 TSS in Z2 I need pretty much zero recovery time. I can repeat that every day no problem. But if I earn 100 TSS for an FTP hour of death then I'm going to suffer for the rest of the day and I certainly can't repeat that kind of effort every day! But on paper they are both equal TSS.