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.
Key points
- 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