Figure skating lifts are required elements in two disciplines of figure skating, pair skating and ice dance. There are five groups of lifts in pair skating, categorized in order of increasing level of difficulty. Judges look for the following when evaluating pair lifts: speed of entry and exit; control of the woman's free leg when she is exiting out of the lift, with the goal of keeping the leg high and sweeping; the position of the woman in the air; the man's footwork; quick and easy changes of position; and the maintenance of flow throughout the lift. Twist lifts are "the most thrilling and exciting component in pair skating". They can also be the most difficult movement to perform correctly. They require more strength and coordination than many other pair elements, and are usually the first or second element in a program. According to the International Skating Union (ISU), the "Lady must be caught in the air at the waist by the Man prior to landing and be assisted to a smooth landing on the ice on a backward outside edge on one foot" during a twist lift. A pair lift and twist lift is required in the short program of pair skating; a well-balanced free skating program in pair skating must include lifts.