The leaders are the lead dogs of a sled, on whom depend its speed and direction. They are not necessarily the leaders of the pack, but they should be able to respond directly to the musher's orders and to impart the impetus and rhythm to the other dogs. Obedient, intelligent and fast, they must know how to quickly execute the fundamentals : take all kinds of turns, change direction, slow down or accelerate, face obstacles and ignore disruptive elements.