Greater maximal O2 uptakes and vital capacities in Tibetan than Han residents of Lhasa

Abstract Maximal O 2 uptake provides an index of the integrated functioning of the O 2 transport system. Whether lifelong high altitude residents have greater maximal exercise capacities than acclimatized newcomers is of interest for determining whether years to generations of high altitude exposure influence maximal O 2 uptake and, if so, what components of O 2 transport are involved. We studied 16 Tibetan lifelong residents of Lhasa, Tibet, China (3658 m) and 20 Han (“Chinese”) 8 ± 1 year residents of the same altitude who were matched for age, height, weight and lack of exercise training. At maximal effort, the Tibetans compared to the Hans had greater O 2 uptakes (51 ± 1 vs 46 ± 1 ml STPD · min −1 · (kg bw) − , P vs 155 ± 6 watts, P P 2 pulse (15.2 ± 0.4 vs 13.3 ± 0.5 ml O 2 consumption/heart beat, P vs 187 ± 3 beats/min, P = NS), supporting the likelihood that true maxima were achieved in both groups. The greater minute ventilation in the Tibetans resulted from greater tidal volume and the greater maximal tidal volume correlated positively with the resting vital capacity. We concluded that the Tibetans achieved a higher maximal O 2 uptake than the Hans, implying an increased capacity for O 2 transport to the working muscle.