(Chamonix) A suspenseful anniversary edition. For the 20th anniversary of the Ultra-trail du Mont-Blanc, 2,300 runners set off from Chamonix on Friday for a daunting journey of more than 170 km through the trails, without a real favorite and in almost winter weather.

As in every edition since 2003, the notes of the bewitching piece “Conquest of Paradise”, by the famous Greek composer Vangelis, will resound at 6 p.m. on the Place du Triangle de l’Amitié, accompanying the first strides of the athletes.

Tens of thousands of spectators who have come to the ski resort for the occasion will encourage these extreme trail runners, who have set off on a journey through three countries (France, Italy, Switzerland) and some 10,000 meters of elevation gain.

The loop, notably passing through Courmayeur, the Grand Col Ferret and Champex, was originally designed to be carried out by hikers in 7 days. But to be considered a UTMB “finisher”, you will have to cross the finish line in 46 hours and 30 minutes.

“It’s our Tour de France, the Champions League final, the most important event of the year”, sums up the British trail runner Damian Hall, 5th in 2018, who will however not start this year.

The fastest should take about 20 hours to complete this tour of Mont-Blanc. But in the absence of Spanish star Kilian Jornet, injured and four-time winner of the event, it is difficult to guess who will be the first to arrive in Chamonix on Saturday.

The Frenchman Mathieu Blanchard, the second and only man with Jornet to have passed under the symbolic bar of 20 hours in 2022 (19 hours 54 minutes 50 seconds), will have to achieve a new outstanding performance to win.

“After the Western States in the United States at the end of June (he finished 7th overall, editor’s note), I took a big blow to my morale, but I arrived in the Chamonix region at the beginning of August and I realized huge weeks of training. I’m not tired, not sore. The signs are there,” the former adventurer of the reality TV program “Koh-Lanta” enthused to AFP on Wednesday.

American Jim Walmsley, who has been living in the region since 2022 with the aim of winning this race – one of the only ones missing from his record – and Briton Tom Evans could still be on par with him.

All runners, elite and amateur alike, will have to deal with difficult weather conditions which prompted the organizers to modify the course at the beginning of the week to avoid paths made impassable by rain and snow, which fell above 2000 meters above sea level.

“This weather is in my favour, says Blanchard, everyone has prepared their cold weather kit, but I’ve been living in Quebec for 10 years, I train in minus 30 degrees in horrible conditions”.

If in men, the suspense remains whole, the women’s race is likely to be crushed by the American Courtney Dauwalter. After her triumphs in the two other major trail races this year (Western States and Hardrock 100), the 38-year-old former science teacher is aiming for an incredible hat-trick, the likes of which have never been achieved in the history of her sport.

Already twice titled on the UTMB (2019, 2021), only a breath away from the overall podium of the last Grand Raid de La Réunion, this atypical phenomenon of trail running could even shake up the top five, all genres combined, at the opportunity for a new exploit.