I don't know what you are asking. If it is running, the basic mileage of long-distance running is 5 kilometers, 10 kilometers is the most comfortable mileage in long-distance running, half horse is the hard mileage in long-distance running, whole horse is the standard hard mileage in long-distance running, and 50 kilometers belongs to cross-country running, which is another classification of long-distance running. Cross-country running corresponds to road running, and the distance and time should be lengthened year-on-year. I can feel the secretion of endorphins and feel better when I am close to nature. I have no concept of hitting the wall. Most of the reasons for retiring are injury or closing the door, which is greatly affected by the environment. Most races are between running and walking. Systematic training is needed, the training module is more complicated, the leg strength and core are more important, and actual combat is the only way to become a master; Need to supplement water, energy and salt, cross-country race needs a certain amount of load-bearing self-supply. 12 hours to solve the battle, two meals for the game. A relatively large supply is needed in the middle of the event; Need to bring more equipment to cope with possible weather and environmental changes. (From Baidu: Hongtugong Treadmill)