Complete Guide to UTMB Series Races: The Four Main Events – OCC, CCC, TDS, UTMB

Introduction

UTMB (Ultra-Trail du Mont-Blanc) is the Olympics of trail running, held annually in late August in Chamonix, France. The race week includes four main races that circle Mont Blanc, crossing France, Italy, and Switzerland. For Taiwanese trail runners, UTMB is the ultimate dream of reaching the world stage, but it is also one of the most demanding race systems in the sport.

Comparison of the Four Races

OCC: The Ideal Entry Point

OCC is the shortest race with the least elevation gain among the four, but the 3,500 meters of cumulative climbing is still a formidable challenge for Taiwanese runners. The course starts from the small Swiss town of Orsières, crossing classic sections such as Champex-Lac and Bovine before reaching Chamonix. For Taiwanese runners tackling European alpine racing for the first time, OCC is the best starting point for familiarizing yourself with the altitude, terrain, and race atmosphere.

CCC: The Path to Advancement

CCC starts from Courmayeur, Italy, and overlaps with the UTMB route in the latter half, making it the standard test before advancing to the UTMB main event. The 101K distance combined with 6,100 meters of climbing requires 20–26 hours to finish, including a full night on the course. Many experienced Taiwanese runners regard CCC as the essential stepping stone to UTMB.

TDS: The Nightmare for Technical Runners

TDS (Sur les Traces des Ducs de Savoie) is the most technically demanding of the four races. The course is mostly single-track trails and scree slopes, and the midnight start forces runners to tackle steep terrain in the dark. If you enjoy technical running, climbing, and solitude, TDS suits you better than UTMB.

The UTMB Main Event: The Ultimate Sanctuary

The UTMB main event starts at 18:00 on Friday evening from Chamonix. Runners must accumulate ITRA points and earn entry through the lottery. The 171K route passes through Les Contamines, Courmayeur, and Champex-Lac before returning to Chamonix. Finishers receive the vest (gilet), one of the highest honors in the world of trail running.

Practical Advice

• Point accumulation path: Taiwanese runners can accumulate Running Stones from ITRA-certified races such as MSIG and HK100, then participate in UTMB World Series events to earn lottery entries
• Altitude acclimatization: It is recommended to arrive in Chamonix 5–7 days before the race and schedule short acclimatization runs
• Gear check: UTMB’s mandatory gear list is strict, with random checks within 48 hours before the race; missing a single item results in disqualification
• Weather preparation: Snow is possible in the high mountains in late August; bring ample waterproof jackets, thermal layers, and headlamp batteries

Conclusion

From OCC to UTMB, every race is a milestone in a trail running career. Taiwanese runners need not rush to tackle the longest distance; gradually accumulating overseas race experience is the way to go far beneath Mont Blanc. It is recommended to take on OCC in the first year, CCC in the second, and finally the UTMB main event—this is the most reliable path.

Related Reading

• Race Preparation Path for UTMB-Level Trail Races: An 18-Month Roadmap
• Taiwan Mountain Ultra: A Preparation Guide for UTMB Asia Series Races
• Trail Race Strategy: A Finish Guide for 100-Mile Races like UTMF and TNF100
• Annual Periodization Template for Trail Running: An 18-Month Path from Zero to UTMB