Time trial

In many racing sports an athlete (or occasionally a team of athletes) will compete in a time trial against the clock to secure the fastest time. In cycling, for example, a time trial (TT) can be a single track cycling event, or an individual or team time trial on the road, and either or both of the latter may form components of multi-day stage races. In contrast to other types of races, athletes race alone since they are sent out in intervals (interval starts), as opposed to a mass start.
In cross country skiing and biathlon competitions, skiers are sent out in 30 to 60 second intervals.
In rowing, time trial races, where the boats are sent out at 10 to 20 second intervals, are usually called "head races."
In many forms of motorsport, a similar format is used in qualifying to determine the starting order for the main event, though multiple attempts to set the fastest time are often allowed. In rallying, the special stages are run in a time-trial format. A similar race against the clock or time attack is often part of racing video games.