The Ultra-Trail du Mont-Blanc captivates thousands every year. What makes these extreme runs so special and how do you best prepare for the enormous physical toll?
The fascination of extreme mountain running can hardly be observed better anywhere than in Chamonix. Every year at the end of August, the French mountain town transforms into the global centre of trail running. According to reports from publications like the Trail Runner Magazine, the event around the Ultra-Trail du Mont-Blanc (UTMB) attracts crowds of athletes and fans. The premier discipline leads over around 170 kilometres and almost 10,000 metres of elevation gain once around the Mont-Blanc massif through France, Italy, and Switzerland. It is a brutal test of endurance for body and mind, where runners are often out all night and under extremely changeable conditions.
How demanding these runs are is shown by the statistics of the UTMB in 2025: Out of 2,492 runners who started, only 1,665 reached the finish line – which corresponds to a finisher rate of about 66 percent. Even absolute top runners like the Briton Jon Albon report in interviews with iRunFar of enormous exhaustion and injury-related dropouts in the past. The time limit for the entire race is 46 hours and 45 minutes. Anyone who wants to survive here must prepare meticulously, as the weather in the Alps can range from summer temperatures in the valley to icy cold and heavy storms on the passes.
So how do you prepare for such extreme physical tolls? The Canadian ultra-runner Emilie Mann explains in an interview with Runners World that preparation goes far beyond simply racking up running kilometres. Specific training stimuli that simulate the actual route profile are important:
In runs over such long distances, the gear often decides between finishing or giving up. Experienced runners like Abby Levene, editor at Trail Runner Magazine, rely on well-thought-out equipment for their tours. This includes a well-fitting, sufficiently large running pack that keeps gear dry, as well as reliable sun protection and lightweight, foldable trail running poles.
The choice of shoes is particularly critical. Emilie Mann emphasises that comfort and cushioning are crucial on extremely long runs to avoid painful shoe changes during the race. At the same time, the shoe should not be too heavy in order to maintain a dynamic running feel. Whether highly cushioned models or shoes with direct ground feedback like the La Sportiva Prodigio 2 – what is important is excellent traction on loose ground and enough space in the toe box so that your feet still feel comfortable even after hours.
Your takeaway: For extreme mountain runs, targeted adaptation to elevation gain and 'time on feet' is more important than pure speed training.
This article was generated automatically with AI from the sources listed above and has not been editorially reviewed.