Physiological profile of middle-aged and older climbers who ascended Gasherbrum II, an 8035-m Himalayan peak

Background. The purpose of this study was to investigate the physiological characteristics of a group of middle-aged and older Japanese climbers who a scended Gasherbrum II, an 8035-m peak in the Karakoram Range of the Himalay as. Methods. Body composition, cardiac structure, and respiratory gas exchange during exercise were estimated in eight climbers with differing levels of e xperience (seven men and one woman, aged 54 to 63 years) 6 months before th eir expedition. Results. Using supplementary O-2, the four experienced climbers ascended be yond Camp 4 (7400 m) without showing any health problems and were able to a ttempt the summit. In contrast, the others, who had minimal experience at e xtreme altitude, suffered from altitude sickness on the way to Camp 4. Body mass index values were relatively high, but their low percentage of body f at (14.9%-21.4%) was indicative of the climbers' substantial lean body weig ht. Cardiac structures were generally normal, although three experienced ma le climbers had borderline hypertension and eccentric hypertrophy of the le ft ventricle. Peak (V)over dotO(2) ranged from 30.9 to 45.6 ml/kg/min, and no significant relationship between fitness level and the success or failur e of the ascent was evident. Conclusions. Even sexagenarians are capable of safely climbing 8000-m peaks with supplementary O-2 An exceptionally high fitness level, as is seen in elite older athletes, does nor appear to be required. What is essential, ho wever, is moderate fitness, good health, and extensive experience.