The effect of induced erythrocythemia on hypoxia tolerance during physical exercise was determined for five male mountain climbers. Treadmill testing was performed under four conditions: 1) prereinfusion, normoxia (Pre-N); 2) prereinfusion, hypoxia (Pre-H); 3) postreinfusion, normoxia (Post-N); and 4) postreinfusion, hypoxia (Post-H). An altitude of 3,566.2 m was simulated by having subjects breathe a gas mixture of 13.5% O2-86.5% N2 at normal barometric pressure. Tests were administered immediately before and 24 h after autologous transfusion of 750 ml of red blood cells. Hematocrit increased from 43.3% at prereinfusion to 54.8% at postreinfusion. Hemoglobin concentration increased from 13.80 g.100 ml-1 at prereinfusion to 17.63 g.100 ml-1 at postreinfusion. Maximal O2 uptake (V̇O2[max], 1.min-1) increased (P < 0.05) by 12.8% (3.28 to 3.70) from Pre-N to Post-N and 13.0% (2.62 to 2.96) from Pre-H to Post-H. Treadmill performance time (s) increased (P < 0.05) by 15.8% (793 to 918) from Pre-N to Post-N and 8.9% (687 to 748) from Pre-H to Post-H. V̇O2[max] decreased by 20.1% from Pre-N to Pre-H and by 9.8% from Pre-N to Post-H. Treadmill time decreased by 13.4% from Pre-N to Pre-H and 5.7% from Pre-N to Post-H. The calculated change in hypoxia tolerance following reinfusion indicated that physiological altitude was improved by 463.6 m. It was concluded that induced erythrocythemia increased hypoxia tolerance during physical exercise.
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of Applied Physiology Respiratory Environmental and Exercise Physiology|
|State||Published - Oct 25 1982|
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