It’s also worth noting that FTP is solely a measure of your capacity to perform at the lactate threshold between aerobic and anaerobic power generation – this doesn’t necessarily reflect your capacity to complete a complex set of intervals that stress you physiologically in multiple ways. Using my FTP value to derive interval sets can result in patterns that are extraordinarily difficult or impossible to complete, because they incorporate certain levels of force or constraints of recovery and anaerobic power.

Trainers with good spindown length are friendlier to ride, e.g. a fluid trainer with a large flywheel or a high quality ergo/wind trainer. The inertia means that you don’t have it spinning down and increasing resistance through the less forceful portions of your pedal stroke.