FTP from an 8-minute test

A shorter, less exhausting protocol: two 8-minute efforts, FTP = 90% of the best average power.

Protocol

After warming up, perform two maximal 8-minute efforts (with generous recovery between them) and use the higher average power of the two as P8.

Formula

FTP = 0.90 × P8

Source caveat (read before using)

Coaching/advisory method (Chris Carmichael / CTS). Has no peer-reviewed academic reference.

The CTS Field Test was developed in 1994 by Chris Carmichael and the Carmichael Training Systems team as a shorter, less taxing alternative to the 20-minute test — it is not derived from a published, peer-reviewed study. It’s kept on the site because it’s widely used in practice, but its basis is commercial/coaching in origin, the weakest among the methods offered here. Prefer the 20-minute or 60-minute test when accuracy is the priority.