Originally Posted by Seattle Forrest

Whatever he's using now. He asked if he should redo the test, so he's got some number for now.

It's a good question, you make excellent points, but that's for down the line because (1) an FTP test is very hard and will fatigue him for several days, throwing off subsequent workouts and that's going to hurt the training more than starting with the wrong FTP number, and (2) because most people need to take the test a few times before they get the hang of it. Better to just adjust the FTP up or down based on if the intervals are too easy or hard - in the beginning while already into a training plan. I would say do the test sooner if not already following a plan. Good plan should include FTP tests every month or two (?) to measure progress anyway.