I am currently training the TT at USAC Pro Nats. I am trying to maximize my performance there and know I need to spend a ton of time making the adaptations in my TT position. For VO2 workouts, I can put out more power sitting upright, which sounds like it would be more beneficial. Should I do all workouts in the TT position or should I do my high intensity workouts where I can put out the most power?
Firstly, the ultimate goal is matching power between road bike and TT bike, so using time during the winter months to work on your position maintenance, comfort, power, and flexibility is super important.
As your season progresses, you should be increasing total time in TT position and trying to progress your power so that it hopefully matches or comes close to your road bike. It’s never going to be the same, but with enough practice, the physiological strain will be the same, so when you do VO2 and it’s 10W lower in TT position, it’ll give you the same adaptation as doing them seated upright on a road bike.
The reasoning behind this is pretty simple - you need to be able to produce big watts at important moments in a TT while in the position, and if you’re not training those systems in a way that mimics race scenarios, it will be more physiologically demanding and inevitably cause you to produce less watts/slow down.
If you have goals in road races as well as TTs, then split your time between the two bikes, one intense session per week per bike is usually what I do, then one more moderate ride on the TT bike focusing on position maintenance.