Hi everyone, lately I have been wondering where do the % of FTP for the different Training zones come from?
I know Coggan came up with them in his book, but are they backed by data and specific physiological changes at around the transition borders or they are just pure educated guesses to make prescription of intensity easier?
Also why is sweet spot 88 to 94% of ftp? When was it determined or who based on what?
I love this zone system I would just like to really know the motivation and data backing it.
Also do other power zone systems exist? While Coggan zones have monopolised the english speaking amateur scene, are there other systems? What zones do professionals use?