Hi. Is the FTP number given by Xert a reflection of what I should be able to do on the bike for 1 hour ? I have a hard time understanding how the software is generating the number after, for example, 3 weeks of VO2Max training. The question comes after a ride I did yesterday. I did a 1 x 5 min all out effort and My FTP went up.

The software expects you to have a pattern of fitness and improvement across all durations. Your FTP affects what you can do for 5 minute effort. All efforts you do on the bike are governed by your FTP to some varying degree and conversely all efforts will improve your FTP to some degree. Xert uses this to help you see changes and to understand how your training affects the value.