The UTMB Index allows runners to compare results from different trail races from all around the world based on their speed. It also demonstrates runners experience at different distances.
The UTMB Index is calculated from the weighted average of a runners best scores, up to the top 5 are taken into account. Runners must have at least one score from races completed in the past 24 months for their UTMB index to be valid, if their UTMB Index is valid then all their results from the past 36 months are used to calculate their UTMB Index.
- The best result is given the highest weight, and the weight progressively decreases for the subsequent four results.
- Newer results receive higher weight than older results.
How do you calculate the UTMB Index for a runner that doesn't have 5 results?
To allow the UTMB Index to be open to as many people as possible, as soon as a runner has completed one race they will receive a UTMB Index. Their UTMB index will be given a slight negative weighting compared to someone who has achieved 5 results. This gives an advantage to runners who have multiple performances, while allowing inclusion of runners with less than 5 results.
This is similar to other sports where you need to have several results to consolidate your performance level.
Do recent and older results have the same importance in the UTMB Index?
Recent results are counted as more important than older results when calculating the UTMB Index. When a result is greater than 12 months old a negative weighting is applied which reduces its value.
My UTMB Index has changed, but I haven't participated in any new races. Why?
Your UTMB Index is recalculated every 24 hours taking into account all the results in the relevant time period. As your result get older they will carry less weighting in the UTMB Index calculation and your UTMB Index will naturally decrease (unless you have new results coming in).