title: [Tolerance for controlled physical loading in chronic hypercapnia in man].
abstract: Young healthy test subjects showed adaptation to chronic hypercapnia during long-term exposure to an atmosphere containing 0.8--1.8% CO2 at normal atmospheric pressure: bradycardia, increase in vital lung capacity and chest movements, improvement of tests with breathing retention and further decrease in oxyhemoglobin. Simultaneously they exhibited an increase in the alkaline reserve of the blood and of the 2 min step-test index. This can be interpreted both as cause and effect: products of glycolysis are bound by buffer bases, thus reducing oxygen uptake per time unit. Study of adaptation to exercises of increasing workload demonstrated an earlier involvement of anaerobic mechanisms than under normal conditions: linear relationship between the workload and heart rate persisted only up to 150 beats/min. By the end of the second and the beginning of the third month of isolation the test subjects displayed deteriorated health state and work capacity in parallel with compensated acidosis.
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D002245:Carbon Dioxide / Q000378:metabolism; D002908:Chronic Disease; D006801:Humans; D006935:Hypercapnia / Q000503:physiopathology*; D010313:Partial Pressure; D005082:Physical Exertion; D012129:Respiratory Function Tests; D012149:Restraint, Physical; D012934:Social Isolation; D013997:Time Factors
chemical_list: D002245:Carbon Dioxide
vernacular_title: Ustoĭchivost' k dozirovannoĭ fizicheskoĭ nagruzki v usloviiakh khronicheskoĭ giperkapnii u cheloveka.