Adverse weather conditions in the Chamonix valley have prompted UTMB organisers to make precautionary changes ahead of the start of main race this evening.
Heavy showers and overcast skies have plagued the valley for the past 48 hours but crucially for the race, last night Chamonix witnessed huge drops in temperature resulting in the freezing level coming down to only 1,700m.
With 10cm of snow expected up high overnight, organisers have taken the decision to shorten the length of the main UTMB race from 168km to 100km and have changed the route to account for the situation at altitude. The other races in the series - the TDS and the CCC - started earlier and have been unaffected by any route changes.
Follow all the action live on UTMB Web TV and for more details on the new route, visit the UTMB News Page.
