NORMOXIC VENTILATORY RESPONSE IN LOWLANDER AND SHERPA ELITE CLIMBERS

The differences in ventilatory response to exercise of some highland e thnic communities is a controversial issue. We have evaluated the diff erences in ventilatory response to exercise at sea level between two g roups of elite climbers, four Himalayan Sherpas (S) and four Caucasian lowlanders (C), after descent from extreme altitude. All of them perf ormed a progressive-intensity exercise test on a treadmill under normo xic conditions. Pulmonary gas exchange was obtained until exhaustion b y means of an automatic gas-analyzer system. Significant differences i n expired Ventilation and carbon dioxide production were found between the two groups, the (V) over dot(E).(V) over dot(O2)(-1) being lower in the S at rest (41.9 +/- 5) in comparison with C (48.7 +/- 9) (P < 0 .05), higher at medium loads of the test (S = 28.2 +/- 4 vs. C = 25.7 +/- 2; P < 0.05) and reaching similar values at higher loads (S = 34.5 +/- 2 vs. C = 35.6 +/- 4; NS). We conclude that the special ventilato ry response observed in these highlanders could explain their adaptati on to altitude, allowing higher oxygen blood saturation at medium work ing loads and reducing the risk of neurological injury caused by a hig h ventilatory response when exercising at high intensity effort under extreme altitude environment. (C) 1998 Elsevier Science B.V. All right s reserved.