I’m always curious by those that make your argument, as it goes against what physiologists and coaches say.
The head coach of TrainerRoad, the guy that created the program, has a blog post that was recently updated:
and it still says this:
TR workouts are based on Coggan classic power zones.
Sustainable power at threshold, your FTP from an accurate field test, is not useless and not about matching it to a ‘a program’
About 5-6 years ago Coggan introduced iLevels to replace classic levels. The motivation is shown in this power-duration chart that has 200 different athletes power curves on a chart:
Which shows that sustained power as % of FTP is basically the same for athletes above say 8-10 minutes, and short power is highly variable between athletes.
