Untrained FTP for a New Cyclist

Depending on two assumptions:

  • Efficiency
  • % VO2max at FTP

the VO2max (relative) can vary quite a bit:

and here are the standards for VO2max by age

Source: Edge 530 - VO2 Max. Standard Ratings

In any case, you can see there are wide swings in VO2max based on your fractional utilization (FTP as % of VO2max) and efficiency. One of several reasons that FTP is considered the single largest determinant of performance.