Having gone through some threads on timetrialling forum where people have reported their 10, 25, 50 and 100 mile power, these are approximately what are reported, as percentages of 25 mile power. Note: I use the word approximately.

10 mile 105%

25 mile 100%

50 mile 95%

100 mile 85% to 90% ? Not many people do 100s so very approximate here.

Trev, your non-understanding of this topic is truly incredible.
Thanks for the entertainment.

Yes, out beyond the first few minutes, the intensity-duration relationship is rather flat, and just keeps getting flatter. This is why if you limit yourself/your thinking to this almost entirely aerobic range, a simple exponential function can be used to describe the data (e.g., Riegel's formula). More importantly, this is why it is unnecessary (as well as incorrect) to try to tie FTP to a specific, fixed duration. Thank you for making my points for me.

You miss the point I was making, which was merely that the 6% increase of power at MLSS or approx 60 minutes Alex was talking about, which causes a dramatic shortening of time to fatigue, also causes similar shortening of time to fatigue at other durations, like 50 mile TT power or approx 2 hour power.

https://forum.slowtwitch.com/...ost=6644120#p6644120