Maximal aerobic capacity at several ambient concentrations of CO at several altitudes
To assess the nature of the combined effect of the hypoxias of altitude (ALT) and CO exposure, 11 men and 12 women nonsmokers served as subjects in a double-blind experiment. The exposure conditions were four ambient CO levels (0, 50, 100, and 150 ppm) at each of four ALT (55, 1,524, 2,134, and 3,048 m). Each subject, after attaining the required ALT and ambient CO level, performed a maximal aerobic capacity test (VO/sub 2/max). Blood samples were obtained before, at 50-W, 100-W, 150-W, and maximum work loads and at the 5th min of recovery. Blood were analyzed for hemoglobin, hematocrit, plasma proteins, lactates, and carboxyhemoglobin (HbCO). VO2max was similar at 55 and 1,524 m and decreased by 4 and 8% from the 55-m value at 2,134 and 3,048 m, respectively. On the basis of all statistical analyses, we concluded that VO2max values measured in men were only slightly diminished due to increased ambient CO. HbCO attained at maximum was highest at 55 m and lowest at 3,048 m. Women's HbCO concentrations were lower than men's. At maximal work loads CO shifted into extravascular spaces and returned to the vascular space within 5 min after exercise stopped. The independence of altitude and CO hypoxias on parameters of the maximum aerobic capacity test and a decrease in the CO to HbCO uptake with increasing altitude were demonstrated and attributed in part to the decrease in driving pressure of CO at altitude.
- Research Organization:
- Univ. of California, Santa Barbara (USA)
- OSTI ID:
- 6459122
- Journal Information:
- J. Appl. Physiol.; (United States), Vol. 65:6
- Country of Publication:
- United States
- Language:
- English
Similar Records
Maximal aerobic capacity at several ambient concentrations of carbon monoxide at several altitudes. Research report, April 1984-January 1988
Alteration in carboxyhemoglobin concentrations during exposure to 9 ppm carbon monoxide for 8 hours at sea level and 2134 m altitude in a hypobaric chamber
Related Subjects
ANOXIA
BIOLOGICAL EFFECTS
CARBON MONOXIDE
AIR POLLUTION
ALTITUDE
BLOOD CHEMISTRY
CARBOXYHEMOGLOBIN
DOSE-RESPONSE RELATIONSHIPS
EXERCISE
SEX DEPENDENCE
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
OXIDES
OXYGEN COMPOUNDS
POLLUTION
560300* - Chemicals Metabolism & Toxicology