EXERCISE TOLERANCE AT HIGH AND LOW ALTITUDES: 'REGULATION OF VENTILATION DURING EXERCISE AT 10,200 FEET IN ATHLETES BORN AT LOW ALTITUDE.'

Abstract : Five champion high school track runners from Lexington, Kentucky were studied at low altitude (1000 ft.) and during 3 weeks in Leadville, Colorado (10,200 ft.). Measurements of minute ventilation, respiratory frequency, tidal volume, mixed expired oxygen concentration, and oxygen consumption were obtained at performance levels ranging from the basal state to maximum treadmill exercise. During maximal effort, oxygen consumption was approximately 25% less in Leadville than in Lexington, whereas minute ventilation, tidal volume, respiratory frequency, and mixed expired oxygen concentration were similar at both altitudes. Similarities in data from a wide range of altitudes suggest that ventilation is regulated in part by some mechanism which senses a given effort in terms of exercise capacity.