Hemoglobin mass and peak oxygen uptake in untrained and trained residents of moderate altitude

Blood composition, hemoglobin mass (CO rebreathing method) and (V) over dot O(2)peak were measured in 15 untrained (UT-Bogota) and 14 trained males (T R-Bogota) living at 2600 m of altitude, and in 14 untrained lowlanders (UT- Berlin). [Hb] amounted to 15.3 + 0.2(SE) g/dl in UT-Berlin, 17.4 + 0.2 g/dl in UT-Bogota and 16.0 + 0.2 g/dl in TR-Bogota. Hb mass was significantly h igher in UT-Bogota (13.2 + 0.4 g/kg, P < 0.01) and in TR-Bogota (14.7 + 0.5 g/kg, P < 0.001) than in UT-Berlin (11.7 + 0.2 g/kg). In TR-Bogota also pl asma volume was expanded. Erythropoietin concentrations in UT-Bogota and TR -Bogota were not significantly increased. There was a positive correlation between blood volume and (V) over dot O(2)peak for the pooled values of all subjects, if the oxygen uptake of UT-Berlin was corrected for an ascent to 2600 m. For the Hb mass - (V) over dot O(2)peak relation two groups are in dicated pointing to two types of altitude acclimatization with different Hb mass increases but similar distribution of aerobic performance capacity. W e suggest that different genetic properties in a population of mixed ethnic origin might play a role.