What is a UTMB Index Race?
A UTMB Index race is an officially certified trail event that contributes directly to a runner's global UTMB Index.
The system categorizes races into four standard distances: 20K, 50K, 100K, and 100M. Because the MoMoFo events are certified, runners who cross the finish line will receive an official performance score in their respective categories:
- The 20-Mile Fun Run applies to the 20K UTMB Index category.
- The MoMoFo 100k applies to the 100K UTMB Index category.
What are the Benefits for Runners?
Finishing an Index race unlocks several advantages within the sport:
- A Global Performance Benchmark: The UTMB Index evaluates a trail runner's performance based on a statistical algorithm. It gives runners a clear number (similar to a handicap in golf or a chess rating) to compare their performance across different terrains and distances worldwide.
- Privileged Race Access: A valid UTMB Index grants runners access to an exclusive pre-sales period and secured early-bird pricing for UTMB World Series Events and Majors on a first-come, first-served basis.
- Better Corral Placement: For large international events, a runner's UTMB Index is used to determine starting wave and corral placement so they are grouped with runners of similar pacing.
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⚠️ Important Clarification: Index Points vs. Running Stones Finishing a UTMB Index race like MoMoFo calculates and validates a runner's UTMB Index, which is mandatory to enter the HOKA UTMB Mont-Blanc (OCC/CCC/UTMB) lottery. However, Index races do not award "Running Stones" (lottery tickets). To get Stones, runners take their newly minted UTMB Index and use it to enter a UTMB World Series Event.
How is the Score Calculated?
The UTMB Index doesn't just look at a runner's raw finishing time—it understands that trail conditions vary wildly.
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The Base Distance & Elevation: The algorithm uses the course distance and total elevation gain/loss as a starting baseline.
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Statistical Peer Correction: The system compares the final times of all participants against a massive database of over 11 million historical race results. If a storm hits the forest or the terrain is exceptionally technical, the overall field slows down. The algorithm automatically recognizes this and adjusts the score upward so runners aren't penalized for tough conditions.
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Overall Index Rating: A runner's overall UTMB Index is calculated using a weighted average of their top 5 results over the last 36 months, with a heavier weight placed on their fastest and most recent races. To keep an index active, a runner simply needs to finish at least one certified race every 24 months.
