Hello, I created a plan with Coach Jack that is on the long side about 40 weeks. In that plan I don’t see any FTP tests or mention of it detecting improvements. How does this work?
Yes we should explain this some how. Generally we believe testing is very individual. We suggest ramp tests and only going to say 95-98% effort. This is close enough and not so painful as other tests, making it more like a workout. Find a stopping point of pain that you can recognize consistently, if that means 100% and you don’t mind then that is fine too. Regarding how often, I would say it depends on the kind of training you are doing and how you feel about it. Meaning during a base period it’s not so important. If you are fairly new to cycling and likely to see big gains during a build or period then once every 3-4 weeks is probably good. For many people once ever 8 weeks is fine. If taking a test and seeing improvement inspires you then more often is probably better. Just don’t do it right before or after a hard day and you could substite any give interval training day with a ramp test. Skipping one workout here or there in this sequence is not critical but if you want to do a ramp test before an interval workout, especially in the beginning phases it’s fine as well.
Hope that helps. In reality you could do 4 tests in 40 weeks and it should be enough to give you a quality workout.
I’d like to add to Alex’s argument. To take the test, rest yourself two to three days. The day before load the carbon (pizza and similar). A well-ventilated room and get started. 
Yes, this is how real men test 
Thank god I am old.