For what it’s worth, I don’t extend my time on the bike before any TR workouts, but I also rarely start a workout ‘cold’. I have some off-bike warm up exercises that I do (largely consisting of dynamic stretching and muscle activation), so that my body is reasonably ready for the workout ahead.
Here’s a video I found a while back, which I think it very good, but can be a little long so I sometimes do only half the number of each movement. There are also some good (and shorter) ride warm up videos on the Dynamic Cyclist YouTube channel.
