Stray-Gundersen, J., Gore, C, J., Rodriguez, F. A., Truijens, M., Townsend, N. E., Williams, K., & Levine, B. D. (2004). Effect of intermittent hypobaric hypoxia on erythropoiesis. Medicine and Science in Sports and Exercise, 36(5), Supplement abstract 2306.

The effect of three hours of intermittent hypobaric hypoxia on erythropoiesis was investigated. Trained athletes (N = 23) were randomly assigned to either hypobaric hypoxia (simulated altitude of 4,000-5,500 m) or normoxia (0-500 m) in a double-blind, placebo controlled design. Both groups rested in a hypobaric chamber for three hours per day, five days per week, for four weeks. Total Hb mass was measured twice before and twice after the treatment. Blood was drawn eight times during the 10-week study, (twice before, once per week during, and twice after) and analyzed for [Hb], reticulocyte Hb, soluble transferin receptor, and erythropoietin (EPO). Blood was also drawn twice (Week 2 and Week 4) within three hours of chamber exposure and assayed for EPO.

There were no differences between groups at baseline, nor were there any differences within or between groups for any variable except EPO. EPO did increase significantly in hypobaric hypoxia to acute chamber exposure, but not in normoxia. There was an acute response to hypoxia demonstrated by a large increase in EPO levels post-chamber exposure. There is no increase in erythroid mass to this mode of intermittent hypoxia as indicated by no change in total Hb mass, [Hb], reticulocyte Hb or soluble transferin receptor. Further, the similarity of the acute response to hypoxia in Wks 2 and 4 indicate no hematologic acclimatization to the intermittent hypoxic exposure.

Implication. Increases in erythropoietin can be achieved by exposing an athlete for three hours a day to a simulated altitude of 4,000-5,500 m per day.

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