I just increase/decrease the workout percentage depending on what my body is telling me that day. I always do everything possible before hitting the - button including suffering for a bit first to see if it's just mental. There are however days where your legs are just blitzed from a tough run earlier in the day or from the day before. Similarly I always wait until 1 interval is complete to hit the + button as well.
I don't believe these subtle changes are anything other than a better sleep or meal plan that day. For this reason I'd never forego the FTP testing protocol every 6th week. I ensure it is repeatable and as scientific as possible within reason (I'm not running a test lab) to ensure it's tailored for me. Call me crazy but I really enjoy the buildup to getting on and doing the test and celebrating the results, good or bad afterwards.
I know a lot of people who don't do FTP testing and I usually attribute it to
1. They are not detail oriented people, so creating a repeatable protocol for the 24 hours leading up to the test is a nuisance
2. They are "by feel" riders who don't care about power figures
3. They have some other personal method to get their numbers
4. They dread a really hard session on the bike
------
"Train so you have no regrets @ the finish line"
I don't believe these subtle changes are anything other than a better sleep or meal plan that day. For this reason I'd never forego the FTP testing protocol every 6th week. I ensure it is repeatable and as scientific as possible within reason (I'm not running a test lab) to ensure it's tailored for me. Call me crazy but I really enjoy the buildup to getting on and doing the test and celebrating the results, good or bad afterwards.
I know a lot of people who don't do FTP testing and I usually attribute it to
1. They are not detail oriented people, so creating a repeatable protocol for the 24 hours leading up to the test is a nuisance
2. They are "by feel" riders who don't care about power figures
3. They have some other personal method to get their numbers
4. They dread a really hard session on the bike
------
"Train so you have no regrets @ the finish line"