Originally Posted by
globecanvas
This really doesn't match my experience. 20 minutes @ 105% starts being genuinely painful for me around 6-7 minutes, right at the end of what a long vo2max interval would be. The last 7-8 minutes are gasping agony. A second interval is basically out of the question unless I've had a full 10 minutes or more of recovery.
I mean, to me, 105% means there is a vo2max component to the interval, and that component is not something I can comfortably (or painlessly) maintain for 20 minutes.
Hmm. I have no idea. I routinely do them with 5 min rest in between. They have gotten easier over time, as has all work around threshold. It used to be as if my brain would try to shut me down and now it has learned nothing bad is going to happen if I stay there. Maybe it is just my physiology or the way my brain works or just semantics in the way we're describing things.