INFNIT™ Marathon des Sables Dataset 1986–2026

The INFNIT™ Marathon des Sables Dataset is the most comprehensive performance record of the Marathon des Sables (MDS) ever assembled. It contains 24,163 athlete records spanning 40 editions from 1986 to 2026, combining finisher data from DUV Statistik (1986–2019) with full athlete records including DNF stage dropout data from LiveTrail (2021–2026). Key features: 23,183 finisher records, 922 DNF records with exact stage-level withdrawal location, athlete demographics, performance tier classification (ELITE/MID/BACK), and velocity data. The dataset captures the first longitudinal record of where athletes withdraw during MDS stages, enabling survival analysis and DNF prediction modelling. This dataset supports the INFNIT™ research programme — an AI-driven ultramarathon performance platform — and is associated with the paper series: INFNIT-I through INFNIT-IV (University of Southampton, MA AI, 2026). **Keywords:**marathon des sables, ultramarathon, DNF analysis, survival analysis, extreme sports, endurance running, stage race, sports analytics, performance data, desert ultramarathon