doubles is 2 runs. The cumulative time of all runs is used to determine finish order. In all three events, the start order after the first run is determined by the outcome of the previous run, with the last-place slider sliding first, the next-to-last place slider sliding second, and so forth, with the leader of the previous run sliding last. Physical measurements of the sled are taken, and the temperature of the sled's steel blades is checked and may not be more than 5 °C (9 °F) above that of a previously established control temperature. Additionally, for artificial track races, the athlete must first be weighed. This is to determine whether the athlete is entitled to carry extra weight on their body while sliding. Men may use additional weight amounting to 75% of the difference between body weight and a base weight of . Women may use additional weight amounting to 50% of the difference between body weight and a base weight of . Doubles athletes may use additional weight amounting to 50% of the difference between body weight and a base weight of . Additional weight is not allowed if the body weight of the front person and back person together exceeds . If one of the partners weighs more than , the weight exceeding the mark is added to the lighter partner. If there should still be a difference between the partner's weight and the mark, the difference can be compensated according to an official weight table. Between runs, athletes are randomly selected for additional weight checks. Before each run, the sled (with the athlete, for artificial track races) is weighed at the start ramp. Once an athlete is on their sled, they are audibly notified that the track is clear. At this point, a tone sounds and the athlete has thirty seconds to begin their run. A run becomes official when an athlete and their sled, in contact with one another, crosses the finish line. If an athlete and sled are not within contact of one another, the athlete is disqualified from further competition. Disqualifications may also take place for any violation of rules and regulations. Certain disqualifications may be appealed. Training The sport of luge requires an athlete to balance mental and physical fitness. Physically, a luger must have strong neck, upper body, abdominal, and thigh muscles. Athletes also use wind tunnels to train. Strength training