[The physiological effects of altitude and motor hypocapnia]

Respiration, blood gas composition and acid-base state were studied in 10 young men at the altitude from 800 to 3340 m above sea level. Development of arterial hypocapnia started at 2000-2500 m. Furthermore PaCO2 was reduced to 10-12 mm Hg as compared to the initial value, under maximal muscular load irrespective of the altitude. Interrelations between high-altitude and exercise hypocapnia are discussed.