HOW DOES THE UTMB INDEX WORK? CALCULATION, LOGIC AND EVOLUTION
Trail running is a unique discipline, shaped by the diversity and unpredictability of natural environments, where every course and every edition is different. Capturing this complexity in a single indicator is a genuine challenge, requiring continuous refinement to improve its accuracy.
Since 2010, the UTMB Index has provided a methodology for evaluating performance in trail running. Recognised by more than 7,000 races worldwide, the tool enables performance comparisons across more than 3 million runners, drawing on a database of over 10 million recorded results.
How is the UTMB Index calculated?
The UTMB Index is an indicator of an athlete’s highest level of performance. It is calculated as a weighted average of a runner’s best scores over the past three years. The higher and more recent a score, the greater its influence on the overall average.
THE SCORE
The score reflects an athlete’s performance in a specific race. It is calculated using a statistical model that predicts the result of each finisher by analysing their past performances in similar races. The model then compares these predictions with the actual results to assess each athlete’s performance. Each race result is analysed through a four-step process.
Learn more FAQ
Why has my UTMB Index recently changed ?
Over the past fifteen years, the discipline has evolved significantly. The widening gap between a global elite capable of pushing the limits of performance and an increasingly large base of runners progressing more gradually has made the balance of the statistical model more complex. As a result, the model has tended to attenuate top-end performances, potentially limiting the visibility of progression among leading athletes.
“In response to these changes, and working closely with the Pro Trail Runners Association (PTRA) and leading figures in the sport, UTMB Group has refined the UTMB Index to improve its accuracy, fairness and relevance.” — Adrian Vincent, Head of Athlete Services and Digital Operations in UTMB Group
The core principles outlined above remain unchanged. The calculation of the UTMB Index and race scores continues to rely on the same statistical model. However, the model has been enhanced with new parameters to better reflect the diversity of race profiles. The integration of factors such as gradient, maximum altitude and competitive dynamics at the front of the race enables a more accurate assessment of faster, more runnable courses, high-mountain formats, and performances delivered in highly competitive fields.
As a result : all scores and UTMB Index values from the past five years have been recalculated based on this updated framework.
“We recognise that the UTMB Index can still be improved. It is entirely natural to question its accuracy, given that the complexity of trail running makes any form of modelling inherently imperfect. Our primary objective is to provide the most fair and relevant indicator possible at any given time. We remain attentive to the community and are committed to continuous improvement, ensuring it evolves alongside the discipline and its participants.” — Adrian Vincent, Head of Athlete Services and Digital Operations in UTMB Group
