Abstract
The effects of a 21-day live high-train low (LHTL) on hemoglobin mass (Hbmass) and iron demand including the erythropoietin (EPO)-erythroferrone (ERFE)-hepcidin axis and routine iron markers were investigated. Fifteen female endurance athletes completed either 21-day LHTL in normobaric hypoxia (2500 m, ~18 h·day−1) (INT, n = 8) or lived and trained in normoxia (CON, n = 7). Hbmass and resting blood were collected before and after the intervention. An additional blood sample was collected on Day 6 for INT. 21-day LHTL increased Hbmass 3.8% in INT (p < 0.001). EPO increased 35.6% from Day 0 to Day 6 in INT (p = 0.037) and then decreased 42.4% from Day 6 to Day 21 (p = 0.019). In INT, no changes were detected in ERFE or hepcidin, and from the routine iron markers only serum transferrin receptor increased from Day 0 to Day 21 (13.9%, p = 0.013). In CON, no changes were detected in Hbmass or iron markers. In INT, Hbmass and ferritin were positively associated (Day 0 to Day 6, p = 0.005). Thus, hepcidin and ERFE may not provide additional information regarding iron demand following 6- or 21-day LHTL compared to routine iron markers. The relationship between Hbmass and ferritin indicates that adequate ferritin levels are needed during hypoxia to support hematological adaptations.
Document Type
Journal Article
Date of Publication
12-1-2025
Volume
13
Issue
24
PubMed ID
41420382
Publication Title
Physiological Reports
Publisher
American Physiological Society
School
School of Medical and Health Sciences
Funders
Finnish Ministry of Education and Culture (OKM/2/626/2023) / Seppo Säynäjäkangas Science Foundation (12/2023) / Kainuu Regional Fund of the Finnish Cultural Foundation (5/2024)
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Comments
Kuorelahti, T., Ihalainen, J. K., Linnamo, V., Badenhorst, C., Kettunen, O., & Mikkonen, R. (2025). “Live high‐train low” induced changes in hemoglobin mass and the erythropoietin‐erythroferrone‐hepcidin axis in female endurance athletes. Physiological Reports, 13(24), e70707. https://doi.org/10.14814/phy2.70707