>>48004
In all seriousness you test ftp so you have a baseline to use for pacing of any kind. So if you underestimate your ftp by like 10% and try to pace intervals off of that you may end up going too easy which leads to less or no gains while overestimating leads to going too hard so you blow up prematurely or can't do many reps of whatever effort you want to do which also leads to less or no gains.

I assume you want to lower it because you struggle with completing your efforts so in that case its actually a good idea to maybe take 5-10 watts off the target if your ftp is overestimated and you can't complete training at all