Livebib

TDS

TDS is the technical crossing of the week: 148 kilometres from Courmayeur to Chamonix, starting at 23:50 on Monday 24 August 2026.

Courmayeur → Chamonix

Distance
148 km
Ascent
+9,305 m
High point
2,589 mCol Chavannes
Start
11:50 PMMon, Aug 24
Create a broadcastOfficial website

The course

The whole race, as a ridgeline

▲ Col Chavannes · 2,589 m

▲ high point

Course & challenge

TDS

The route climbs immediately to Maison Vieille and the Arête du Mont-Favre before the Col Chavannes at 2,580 metres, then drops the length of the Tarentaise to Bourg-Saint-Maurice at 50 km, the lowest point of the race. The second half is the harder one: the Passeur de Pralognan at 61 km, the Cormet de Roselend, Beaufort at 92 km, and the Col de Tricot at 130 km before the descent through Les Houches. With 9,300 metres of ascent over a midnight start, most runners cover two nights on the course.

The facts here are fixed to the 2026 TDS. Its start village, gun time and elevation profile belong to this edition, and a later course change will not rewrite them. Livebib stores the race course once, so every broadcast linked to this race shares the same route and keeps it with the replay.

The climbs

The climbs that decide the day

  1. 01

    Arête du Mont-Favre

    10.7 km+1,237 m11.6 %

    crest at km 12.1

  2. 02

    Col Chavannes

    5.3 km+633 m11.9 %

    crest at km 20.4

  3. 03

    Col de Forclaz

    8.5 km+1,556 m18.2 %

    crest at km 58.1

  4. 04

    Col de la Gittaz

    5.4 km+747 m13.8 %

    crest at km 77.8

  5. 05

    Dôme de la Girotte

    3.8 km+764 m20.3 %

    crest at km 103.8

The course

On the map

TDS 2026Open the full-resolution map

Course data verified August 12, 2026