Run in a natural environment, discover the most hidden paths in the mountains, in the woods, on the plains or in the hills. It is the trail running, the race that runs on mostly dirt tracks and which involves overcoming both positive and negative gradients. Trail running has been recognized as a discipline of athletics in 2015 for the 50th Iaaf competition. Trail running races of less than 42 kilometers are defined as "trails" and are characterized by differences in level close to 3000 meters. The most demanding races are called ultra trails if they exceed 42 km: the Tor des Geants, for example, is a race that winds through 7 sectors for a total of 331 km and more than 20 thousand meters in altitude (positive and negative). To deal with these bumps, you need equipment at height, starting with shoes specifically to study for trail running.