Relay races are the only track and field event in which a team of runners directly compete against other teams. Typically, a team is made up of four runners of the same sex. Each runner completes their specified distance (referred to as a leg) before handing over a baton to a teammate, who then begins their leg upon receiving the baton. There is usually a designated area where athletes must exchange the baton. Teams may be disqualified if they fail to complete the change within the area, or if the baton is dropped during the race. A team may also be disqualified if its runners are deemed to have wilfully impeded other competitors.