The process quantifies an individual’s Functional Threshold Power (FTP) by assessing the highest average power output sustainable for a 20-minute duration. The average power achieved during this time is then adjusted, typically reduced by 5%, to estimate the FTP. For example, if an athlete averages 300 watts during the 20-minute effort, the estimated FTP would be 285 watts (300 x 0.95). This adjusted value represents the estimated maximal power output that can be maintained in a sustained, quasi-steady-state.
Establishing a reliable FTP is essential for effective training prescription in cycling and other endurance sports. It enables individualized training zones, optimizing workouts for specific physiological adaptations. Historically, longer duration time trials were utilized to estimate FTP; however, the 20-minute assessment offers a practical and time-efficient alternative, balancing accuracy and feasibility for athletes of varying levels.