A pacemaker or pacesetter, sometimes informally called a rabbit, is a runner who leads a middle- or long-distance running event for the first section to ensure a fast time and avoid excessive tactical racing. Pacemakers are frequently employed by race organisers for world record attempts with specific instructions for lap times. Some athletes have essentially become professional pacemakers. A competitor who chooses the tactic of leading in order to win is called a front-runner rather than a pacemaker.
Pacemakers may be used to avoid the tactics of deception that are possible in competition by those who, for example, race away from the start line (and are likely to subsequently slow down), giving the other runners the impression that they are far behind. A trusted team of pacemakers who are paid to keep the runners at a speed that they can manage for the rest of the race become useful in such a situation. Pacemakers are also used on world record attempts in order to make sure that the runner knows where their invisible 'opponent' predecessor is at that stage of the race. Pacemakers serve the role of conveying tangible information about pacing on the track during a race. Pacemakers may also facilitate drafting.
Pacemaking gained much usage after Chris Brasher and Chris Chataway successfully paced Roger Bannister to break the four-minute mile for the first time in 1954.