Last updated: 3 October 2026
Reviewed by Jordan Morley, FA Level 2 Football Coach
FTP (Functional Threshold Power) is the maximum average power output sustainable for approximately 60 minutes. It is the cornerstone of power-based cycling training — all training zones are calculated as percentages of FTP. A 20-minute all-out test (multiplied by 0.95) provides a commonly used estimate. FTP increases with structured training, particularly sweet spot and threshold work. W/kg (watts per kilogram of body weight) normalises FTP for body size and is the standard performance benchmark.
- Max sustained power for ~60 minutes
- Training zones are % of FTP
- 20-min test × 0.95 = estimated FTP
- W/kg normalises FTP for body weight
In practice
FTP (Functional Threshold Power) is the central number cyclists build their entire training zone structure around — it represents the highest average power a rider can sustain for about an hour, and every other training zone (recovery, endurance, threshold, VO2 max, anaerobic) is calculated as a percentage of this one benchmark figure.
FAQ
How is FTP tested?
The most common field test is a 20-minute maximal effort, with FTP estimated as 95% of the average power from that effort; some protocols use a full 60-minute test for a more direct measurement.
How often should FTP be retested?
Every 6-8 weeks during a structured training block is typical, since FTP improves with training and outdated zones based on an old FTP number reduce training precision.