Simple version from some recent posts from TR CEO Nate:
- power data
- historical power data
and then it calculates FTP probability across a range of watts. For example it may give highest probability (likelihood) that your FTP is 250W, but there is still a 13% chance its 265W (from that link above).
Estimates can improve if you feed it power data with more efforts near your current fitness level.
As an aside, in a similar manner you can estimate FTP from 60-90 day power data just by looking for the ‘knee of the curve’ on a power duration curve, or ‘drop’ in power histogram. Knowledge of the efforts including in the data set, and previous ftp results, can help guide the results of your visual analysis.
Long and short, support@trainerroad.com can take a look and better comment on the specifics of your data and AI FTP estimate.