The latest addition to the Mont Blanc Marathon event is the Mont-Blanc 80km Ultra, a gruelling race which will see runners climb cover some spectacular scenery.
Setting off before first light from Chamonix the runners will cover a challenging 6,000 metres of vertical climb along 80km's of ridges, snow fields, Swiss territory and glaciers.
The race is limited to 1000 runners and awards 3 UTMB points.
The race starts at 4am and the first finishers are expected at around 14:30.
Location: Chamonix / Mont Blanc Valley
Event: Races / Competition | Sports Event
Venue Style: Open Air / Outdoors