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. 2025 May 1;57(5):904-911.
doi: 10.1249/MSS.0000000000003621. Epub 2024 Dec 4.

Accelerated Red Blood Cell Turnover Following Extreme Mountain Ultramarathon?

Bastien Krumm, Antoine Raberin  1 , Tom Citherlet  1 , Guia Tagliapietra  1 , Raphael Faiss, Vincent Pialoux  2 , Tadej Debevec, Guido Giardini  3 , Grégoire P Millet  1
Affiliations

Accelerated Red Blood Cell Turnover Following Extreme Mountain Ultramarathon?

Bastien Krumm et al. Med Sci Sports Exerc. .

Abstract

Introduction: Mountain ultramarathon (MUM) induces extreme physiological stress for the human body. For instance, a decrease in total hemoglobin mass (Hbmass) due to severe hemolysis is historically suspected. Nevertheless, hematological changes following a 330-km MUM have to date never been investigated.

Methods: Blood volumes were determined before (pre-) and after (post-) a 330-km race completed by 13 participants, through the automated carbon monoxide (CO)-rebreathing method. Native viscosity and normalized blood viscosity were determined using a cone/plate viscometer at five different speeds (11.25 to 225 s -1 ). Biomarkers of inflammation, erythropoiesis, and hemolysis were additionally quantified.

Results: Following the race, an 18% rise in plasma volume (3338 ± 568 vs 3928 ± 590 mL, P = 0.001) was observed, whereas absolute Hbmass (802 ± 102 vs 833 ± 111 g, P = 0.09) did not change significantly. A decrease in native viscosity was reported at all speeds ( P < 0.001) with a significant reduction for normalized viscosity at low to intermediate speeds only (i.e., 11.25, 22.5, and 45 s -1 ). Marked inflammation was suggested by upregulated interleukin-6 (7.1 ± 8 vs 16.5 ± 14 ng⋅L -1 , P = 0.011) and C-reactive protein levels (12.3 ± 14 vs 51.6 ± 14 μg⋅mL -1 , P = 0.001). Besides, the increased erythropoietin (5.7 ± 3 vs 12 ± 6 mU⋅mL -1 , P = 0.021) and erythroferrone levels (6.5 ± 4 vs 8.5 ± 4 ng⋅L -1 , P = 0.001) may indicate enhanced erythropoiesis.

Conclusions: Overall, these findings suggest an enhanced red blood cell turnover, probably triggered by limited exercise-induced hemolysis (although still supported by the decrease in corrected viscosity), likely balanced through accelerated erythropoiesis.

Keywords: ERYTHROPOIESIS; HEMOLYSIS; HYPOXIA; RED BLOOD CELLS; ULTRAENDURANCE.

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Figures

FIGURE 1
FIGURE 1
BVs pre- and postrace. Hematocrit (A), hemoglobin concentration (B), BV (C), PV (D), total hemoglobin mass (E), and RBC volume (F). **P < 0.01 and ***P < 0.001 for the difference between time points.
FIGURE 2
FIGURE 2
Native (A) and normalized (B) blood viscosity pre- and postrace for different share rates. *P < 0.05 for the difference between time points.
FIGURE 3
FIGURE 3
Markers of hemolysis and erythropoiesis pre- and postrace. Erythropoietin (B), hepcidin (B), erythroferrone (C), haptoglobin (D), CRP (E), and fibrinogen (F). *P < 0.05, **P < 0.01, and ***P < 0.001 for the difference between time points.
FIGURE 4
FIGURE 4
Correlations between PV (A), BV (B), CRP (C), and haptoglobin (D) with running time.
See this image and copyright information in PMC

References

    1. Le Goff C Viallon M Kaux JF, et al. . Kinetics of cardiac remodeling and fibrosis biomarkers during an extreme mountain ultramarathon. Front Cardiovasc Med. 2022;9:790551. - PMC - PubMed
    1. Saugy J, Place N, Millet GY, Degache F, Schena F, Millet GP. Alterations of neuromuscular function after the world's most challenging mountain ultra-marathon. PLoS One. 2013;8(6):e65596. - PMC - PubMed
    1. Mairbaurl H. Red blood cells in sports: effects of exercise and training on oxygen supply by red blood cells. Front Physiol. 2013;4:332. - PMC - PubMed
    1. Pugh LG. Blood volume changes in outdoor exercise of 8-10 hour duration. J Physiol. 1969;200(2):345–51. - PMC - PubMed
    1. Robach P Boisson RC Vincent L, et al. . Hemolysis induced by an extreme mountain ultra-marathon is not associated with a decrease in total red blood cell volume. Scand J Med Sci Sports. 2014;24(1):18–27. - PubMed