Is hemoglobin desaturation related to blood viscosity in athletes during exercise?

P. Connes, D. Bouix, F. Durand, Pascale Kippelen, J. Mercier, C. Prefaut, J. F. Brun, C. Caillaud

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    Several studies have suggested that athletes with low hemoglobin saturation during exercise may experience impaired pulmonary blood gas exchange during maximal exercise. Blood viscosity may be implicated in exercise-induced pulmonary hemorrhage in race horses. We hypothesized that blood theology may contribute to impaired gas exchange and reduced hemoglobin saturation during exercise in humans. A group of 20 highly trained endurance athletes participated in this study, 9 with low hemoglobin saturation during exercise (Low-SpO(2) group) and 11 with normal hemoglobin saturation (High-SpO(2) group). All subjects performed a progressive exercise test conducted to VO(2max)Venous blood was sampled at rest, 50% VO2max and maximal exercise. Blood viscosity (etab) was measured at very high shear rate (1000 s(-1)) and 37degreesC with a falling ball viscometer. The erythrocyte rigidity coefficient, "Tk", was calculated using the Dintenfass equation. At rest, no significant difference in etab was observed between the two groups (3.00 +/- 0.08 mPa.s vs. 3.01 +/- 0.04 mPa . s for the Low-SpO(2) and High-SpO(2) group, respectively). At 50% VO2max and maximal exercise, etab was higher in Low-SpO(2) (p < 0.01). Tk decreased in High-SpO(2) (p < 0.01) but remained unchanged in the other group during testing. The greater increase in etab in the Low-SpO(2) group during exercise may therefore have been due to the lack of reduction in Tk. As suggested by previous studies, the greater increase in blood viscosity in athletes with low hemoglobin saturation may lead to vascular shear stress. Whether this could impair the blood gas barrier and result in exercise-induced hypoxemia requires further study.

    Original languageEnglish
    Pages (from-to)569-574
    Number of pages5
    JournalInternational Journal of Sports Medicine
    Issue number8
    Publication statusPublished - 2004


    • hypoxemia
    • red blood cell
    • hemorheology
    • endurance
    • STRESS
    • VOLUME

    Cite this

    Connes, P., Bouix, D., Durand, F., Kippelen, P., Mercier, J., Prefaut, C., Brun, J. F., & Caillaud, C. (2004). Is hemoglobin desaturation related to blood viscosity in athletes during exercise? International Journal of Sports Medicine, 25(8), 569-574.