In many racing sports an athlete will compete (take part) in a time trial. This is when the athlete races over a course as fast as he can. In cross country skiing and biathlon competitions, a skier will start every 30 to 60 seconds. These are called interval starts. In cycling a time trial (TT) can be a single track race, or an individual time trial on the road. Time trials are often a part of a stage race, for example the Tour de France.