Skate skiing is a nordic ski techniche where the skier provides propulsion on a smooth, firm snow surface by pushing alternating skis away from one another at an angle, in a manner similar to ice skating. Designed for skiing on groomed surfaces. Recommended ski lengths are between 170 and 200 centimetres (up to 110% of the skier's height) for adult skiers. The entire bottom of each skate ski is a glide zone—prepared for maximum glide. Traction comes from the skier pushing away from the edge of the previous ski onto the next ski.