BLOOD ADAPTATIONS TAKE 10 WEEKS AT MODERATE ALTITUDE
McGregor, J., Minares, C., Ruth, C., Pinchak, A., Zupan, M. F., Nelson, J. L., & Brothers, M. D. (2009). Hemoglobin mass and erythrocyte volume adaptations after 10 weeks of altitude in sea level females. ACSM 56th Annual Meeting, Seattle, Washington. Presentation number 2364.
This study assessed adaptations to moderate altitude (2,210 m) of total hemoglobin mass, erythrocyte volume, plasma volume, and total blood volume in sea-level females (N = 18) at the U.S. Air Force Academy. It was hypothesized that sea-level females would display significant gains in all hematological parameters over time. Ss' hemoglobin mass was assessed within the first 72 hours of in-processing at the Academy, and after 6 and 10 weeks of living at moderate altitude. During these same assessments, a controlled, seated venipuncture was conducted and erythrocyte volume, plasma volume, and total blood volume was calculated utilizing the total hemoglobin mass data, hemoglobin concentration, and hematocrit. Relative total hemoglobin mass values were compared to the average total hemoglobin mass values measured among upper-class Academy females (N = 20) who had resided at moderate altitude for more than two years.
Former sea-level females had significant increases in total hemoglobin mass (~12.5%) and erythrocyte volume (~10.8%) following 10 weeks of chronic moderate-altitude adaptation. Neither blood nor plasma volumes changed significantly. Sís total hemoglobin mass was significantly lower acutely and following six weeks of moderate-altitude exposure compared to moderate-altitude controls, but was not significant at week 10.
Implication. Adaptation to 2,210 m combined with military training resulted in significant increases in total hemoglobin mass and erythrocyte volume which required 10 weeks to reach the hematological values similar to those of long-term moderate-altitude adapted females.
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