Accession Number : AD0666044

Title :   ATTEMPTED ACCLIMATIZATION BY VIGOROUS EXERCISE DURING PERIODIC EXPOSURES TO SIMULATED ALTITUDE.

Descriptive Note : Final rept. Sep 65-Apr 66,

Corporate Author : INDIANA UNIV MEDICAL CENTER INDIANAPOLIS CARDIOPULMONARY LAB

Personal Author(s) : Murray,Raymond H. ; Shropshire,Spencer ; Thompson,Leonard

Report Date : SEP 1967

Pagination or Media Count : 18

Abstract : Acclimatization to altitude by means of periodic short-term chamber exposures could have military and athletic application by preparing unacclimatized subjects for endurance performance at altitude. Three unconditioned men were trained daily by endurance running for 3 weeks at ground level. Following control measurements, they exercised strenuously on a treadmill 2 hours daily for 17 days in a chamber at a simulated altitude of 2300 meters. Responses were evaluated by: symptoms; maximum work performance (as measured by the duration of exercise-to-tolerance); maximal heart rate; duration of breath-holding; production of lactate and excess lactate; maximum expiratory minute volume and oxygen consumption. During the initial periods of exercise at altitude, maximum work performance fell significantly from control levels (average 23%), with striking symptoms of exhaustion; breath-holding duration fell 13%; the production of excess lactate rose significantly in two subjects. Over the remainder of the altitude exposures exercise performance and breath-holding duration increased to near control levels while fatigue was much less noticeable. Maximal heart rate varied greatly. There was no significant change in maximal oxygen consumption during exercise at altitude, but expiratory minute volume rose slightly. During the period of altitude exposures, symptoms common with chronic exposures (malaise, Cheyne-Stokes respiration, rheumatic complaints) were often noted both in the chamber and at work and at home. (Author)

Descriptors :   (*ACCLIMATIZATION, *EXERCISE(PHYSIOLOGY)), ENDURANCE(PHYSIOLOGY), PHYSICAL FITNESS, RESPONSE(BIOLOGY), PERFORMANCE(HUMAN), TOLERANCES(PHYSIOLOGY), PULSE RATE, RESPIRATION, LACTATES, OXYGEN CONSUMPTION, FATIGUE(PHYSIOLOGY), HIGH ALTITUDE

Subject Categories : Personnel Management and Labor Relations
      Stress Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE