I guess that would depend on the rules of the race you are doing. With mine, I have to have my bike in the transition area and racked the night before it all starts. So there would be no way to warm up on it anytime after the day before. Not sure how common that is, but I would imagine they all require the bike to be in the transition area hours before the swimmers even start. But again - I'm a total novice, so all I can really speak to is my race this fall.