Research studies on the practice of ultra-endurance trail running—ultra-trail running—are proliferating and reflect the very popularity of this sport. This article provides an exhaustive and interdisciplinary review of the literature on this emerging area of research. A meta-analysis based on 176 references highlights the contributions of the medical and social sciences. Finally, the systematic analysis of the corpus in the Nvivo software reveals a terminology structured around four themes: 1. medical and physiological approaches, 2. commitment and profiles, 3. motivations and experiences of practice, 4. territories of trail-running. These results allow a comprehensive synthesis of the research carried out so far and constitute a starting p...