Originally Posted by
southernfox
But this is true on the road, too, depending on what road one is doing their 20' test. So I don' t think it's an issue at all.
Sure, again depending on what conditions you choose when you test... however the point of an FTP "test" is to try to remove as many variables as possible. That's why most are done on a trainer or a steady incline. Certainly you CAN do it on a mountain bike trail if you wanted... but why would you?