FTP (Functional Threshold Power)

FTP is the highest average power, in watts, that a cyclist can sustain for approximately one hour. It is the foundational reference value used to set every training zone and prescribe every interval workout. FTP is the single most important number in power-based cycling training.

FTP ≈ 95% of 20-minute all-out average power
    (20-min test protocol, per Coggan)

FTP is typically estimated rather than measured — a true 60-minute maximum effort is brutal and rarely done. The standard protocols are the 20-minute test (ride all-out for 20 minutes, take 95% of the average) and the ramp test (ride increasing-intensity ramps to exhaustion, FTP ≈ 75% of the final 1-minute power).

More recent approaches — notably Kolie Moore's TTE protocol — argue for a time-to-exhaustion test at a power you can sustain for 30–70 minutes, which more directly measures the underlying physiology. Power-duration modeling (Critical Power, W') is another route that estimates FTP from multiple shorter-duration efforts.