Factors affecting a climber’s ability to ascend Mont Blanc

The aim of the study was to determine the factors affecting a climber’s ability to ascend Mont Blanc using a number of variables collected at the Gouter Hut (3,817 m) before and after an attempted ascent on the Mont Blanc summit. Subjects (n=285) were tested at 3,817 m prior to their ascent of Mont Blanc. Maximum height ascended in the last 14 days was recorded. End tidal CO₂, arterial oxygen saturation (SaO₂), heart rate and respiratory rate were measured using a Capnograph (Nellcor Patrick NPB75). Acute mountain sickness (AMS) was assessed using the Lake Louise scoring system. Summit information is available for 216 subjects. None of the subjects who attained 4,000 m in the previous 14 days failed to reach the summit (P=0.04). Previous recent exposure to an altitude of 4,000 m resulted in faster ascent times to the summit than those who had not been above 3,000 m in the previous 14 days (4.02±0.6 vs. 4.46±0.8 h, P=0.009), higher SaO₂ on arrival at the Gouter Hut on day 1 (88.6±5 vs. 86.3±6%, P=0.004) and lower AMS scores upon arrival at the Gouter Hut after the attempted ascent to the summit 2.5±1.8 versus 4.7±2.5 U (P=0.001), respectively. It is concluded that recent exposure to 4,000 m confers an advantage to those who wish to ascend a 4,800 m peak.