An individual time trial (ITT) is a road bicycle race in which cyclists race alone against the clock (in French: contre la montre – literally "against the watch", in Italian: tappa a cronometro "stopwatch stage"). There are also track-based time trials where riders compete in velodromes, and team time trials (TTT). ITTs are also referred to as "the race of truth", as winning depends only on each rider's strength and endurance, and not on help provided by teammates and others riding ahead and creating a slipstream. Individual time trial are usually held on flat or rolling terrain, although sometimes they are held up a mountain road (in Italian: cronoscalata "chrono climbing"). Sometimes the opening stage of stage race is a very short individual time trial called a prologue.