I was going to use a TR developed training plan - all my rides will be outside. I do not use a Power Meter but HR and RPE. The TR plan references so many minutes at a % of FTP. Would I use the % of the FTP as a reference to HR Zone? For example if the FTP is 75% then I would be looking at a HR zone of 3 or 4? Also I live in a hilly area so when training it is a matter of maintaining the effort either going up the hill or down? Thanks - obviously I have no idea what I am doing so any information will help