Runners are known in the Inca civilization under the name chasquis (chaskis). They were messengers of the empire, and were in charge of carrying messages and gifts. Highly trained and physically well-prepared, they ran 240 km a day through a well-regulated chaskis relay system. It was the main mode of communication in the Inca Empire, where mostly young people, whose services were used by the military and the emperors and merchants as well.