Pez on Warm up

Pez has a good summary of warm up requirements here.

While he is using Cross and running late due to shorter daylight hours etc etc.... One of the studies he references is about tests using a 3km TT.

The results are not astounding but worth repeating:

In summary, any kind of moderate to hard warm-up seems infinitely preferable to no warm-up at all. Therefore, set your departure time and stick to it! Also, do whatever you need to in order to trim and optimize your on-site preparation so that you’re not fiddling away precious time once you arrive.

I know that I always seem to find a million things to do other than getting on the bike and getting warmed up... And typically don't want to fatigue myself and probably then don't do enough Tempo.