Due to the growing increase in participants in trail running and the earliness in their practice, the need to know the reasons why these young people decide to engage in this demanding sport has arisen, as well as how it influences their personal development. 40 technified athletes from all over Spain (28 men, 12 women) participated in this mixed study to answer the different questions raised. It was observed that most of them began to practice it thanks to people close to them (60%). In terms of the aspects that have been influenced by the practice of this sport, they include; their outlook on life (29%), their habits and responsibilities (28%) and friends (26%). Finally, 48% of participants found that trail running can help them with their mindset to face problems and other situations in the future from which it is concluded that trail running could stimulate the development of a resilient personality (hardiness) among its practitioners.