To determine the hardness of a sport, it is necessary to take into account the duration of the effort , the sum of the aerobic and anaerobic efforts , the temperature and the altitude where it takes place. Of course, always considering the hypothetical case of athletes who possess identical bodily and physiological characteristics (weight, height, cardiovascular capacity, etc.) In terms of duration, the cycling events of a great lap take the cake. However, it happens that between each day there are rest and recovery sessions. For this reason, long-distance events such as the marathon and the 50 km walk, and the queen test of cross-country skiing, the 50 km, take precedence over cycling races.
From an endurance point of view, cyclists and runners only perform aerobic efforts while skiers combine aerobic and anaerobic expenditure, so their sport requires more preparation. In addition, in the case of skiers, when practicing at a high altitude, between 1,500 and 1,900 meters, the effort is multiplied. If we add to this the low temperatures, sometimes 20 degrees below zero, which imply greater wear and tear due to the loss of body heat, it must be concluded that cross-country skiing is the most demanding sport.
