It is the fundamental phase before a time trial. At what intensity should I warm up? How much time? How long does it take to finish heating? Here are some indications taken from the UAE team on the occasion of the first stage of the Tirreno-Adriatico 2019, a team time trial of about 21 km.
We start pedaling on the trainers, the first part of the warm up should end when we start to sweat slightly (on a hot day this first part can last very little, even just 5 minutes).
The heating continues making a progression raising the beats (better the watts if you have a power meter mounted on the bike) at the intensity that will then be kept in motion (depending on the length of the time trial). The intensity should be increased on a regular basis by raising a step every 30 seconds. This phase should last about 7/8 minutes. Later, easy pedaling for about two minutes.
At this point it is necessary to perform three minutes at medium intensity with 6 seconds of hard effort (peak) every minute, at a cadence of more than 120 rpm (pedaling per minute) to awaken the fast fibers that can be involved during the effort. We must then finish with two minutes at low intensity to loosen the legs well. The warm up must finish about 7/5 minutes before the start.
To sum up
5/10 minutes: normal pedaling, warming up to sweat well
7/8 minutes: regular progression up to the race intensity
2 minutes: quiet ride
3 minutes: pedal at medium intensity and every minute do 6 seconds of agile sprint for more than 120 rides per minute.
2 minutes: easy