There are three ways to establish your FTP: a blood lactate test, a 60 minute test, or a 20 minute test.
A blood lactate test is typically performed in a sports performance lab–not exactly something everyone wants to pay for or undergo regularly.
Zwift Workouts to the Rescue
Fortunately, Zwift has built-in workouts for 60 and 20-minute FTP tests. I recommend hitting one of these workouts on a day when you’re well-rested, so you can establish a solid baseline FTP for future training efforts.
Want to know what you’re in for? Here’s a quick video Chris Pritchard made summarizing his experience doing the 20-minute FTP test on Zwift for the first time:
Automatic FTP Measurement
Along with the structured FTP test workouts, Zwift will automatically detect your FTP from your everyday Zwift riding, and prompt you when it detects an increased FTP as you finish your ride.