Fig. 1. V^·_O2max measured before, during the course of and after a typical exposure to altitude for an expedition to Mount Everest base camp (open symbols, sea-level measurements; filled symbols, altitude measurements. Values are means ± S.E.M. for 10 subjects. The asterisk demonstrates that the pre-exposure value is significantly different from all other measurements (P<0.05). From Cerretelli and Hoppeler, 1996, with permission.