Doing an FTP test is not the most pleasant of past times! However it really is essential to set your power zones and get the most out of your training.
It’s not unusual to get different results doing indoor and outdoor FTP tests and there are all sorts of reasons why that might be – inherent differences between the biomechanics of riding on road or in a fixed position on a turbo trainer, the constant fluctuations in road surface and gradient, environmental conditions and motivation to name but a few. This Training Peaks blog goes into some detail about the biomechanical differences in particular.
Is it really worth doing specific FTP tests indoors and out? That’s a difficult one to answer definitively. On balance though, I’d say probably not for the following three reasons;
- Your fitness is constantly changing depending on the training you have been doing recently, and the accumulated training over a greater period of time, plus how rested you are. If you did regular FTP tests – say every day, or even several times a day, the chances are your results would be slightly different every time anyway. Then there’s motivation – you need to be really motivated to turn yourself inside out for an accurate FTP test.
- Have you tried sticking to exactly 250 Watts (or any other power)? Unless you are on Trainer Road or similar where it’s electronically controlled, it’s impossible to produce an exact amount of power for any length of time. Even on a turbo trainer there is a big fluctuation in the power we produce, and on the road just being in the ballpark can be challenging at times!
- Specific physiological adaptations don’t ONLY happen at certain power outputs – or even in certain power zones or levels. Physiological processes are complex and occur on a continuum rather than at specifically defined power outputs. We use zones or levels to indicate a region where certain physical adaptations are most likely strongest, but those adaptations occur throughout a whole range of power outputs and zones or levels to a varying degree.
