Speed skating is also called avenue speed skating. Athletes race against time on a 400-meter-long field. This is absolute speed, which needs one word-fast. Therefore, the speed skating knife is long, the blade is narrow and flat, the sliding area is large, the friction resistance is small, and the shoe waist is short, which is convenient for athletes to lower their body center of gravity and reduce air resistance. Moreover, the skates of speed skating skates only have the front point fixed on the sole, and the back point can be separated from the skates when the athletes slide (especially when they slide in a straight line), which looks like a pair of shoes. This is mainly because this kind of "dislocation knife" can prolong the contact time between the skates and the ice surface when athletes pedal ice, so that athletes can make full use of the strength of their ankles to achieve "combination of legs and feet", improve skating efficiency and increase skating distance.