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Single versus Split Dose of Iron Optimizes Hemoglobin Mass Gains at 2106 m Altitude
Abstract
Purpose: To determine if a single versus a split equivalent daily dose of elemental iron was superior for hemoglobin mass (Hbmass) gains at altitude while minimizing gastrointestinal (GI) discomfort. Methods: Twenty-four elite runners attended a 3.1 ± 0.3 wk training camp (Flagstaff, AZ; 2106 m). A two-group design, randomized and stratified to baseline Hbmass, sex, and ferritin (>30 μ·L −1 ), was implemented daily as: 1) single dose of 1 × 200 mg ( pm only, SINGLE) versus 2) split dose of 2 × 100 mg ( am and pm ; SPLIT) elemental iron (ferrous fumarate). The Hbmass and venipuncture assessments were completed upon arrival and departure (±2 d) from camp for ferritin, hepcidin, and erythroferrone (ERFE) concentrations. Validated food frequency, GI distress, menstrual blood loss (MBL) and training questionnaires were implemented throughout. Univariate analysis was used to compare Hbmass, with baseline ferritin, dietary iron intake, MBL, and training volume used as covariates. Results: Both conditions increased Hbmass from baseline ( P < 0.05), with SINGLE (867.3 ± 47.9 g) significantly higher than SPLIT (828.9 ± 48.9 g) ( P = 0.048). The GI scores were worse in SINGLE for weeks 1 and 2 combined (SINGLE, 18.0 ± 6.7 points; SPLIT, 11.3 ± 6.9 points; P = 0.025); however, GI scores improved by week 3, resulting in no between-group differences ( P = 0.335). Hepcidin significantly decreased over time ( P = 0.043) in SINGLE, with a nonsignificant decrease evident in SPLIT (~22%). ERFE significantly decreased in both groups (~28.5%; P < 0.05). No between-group differences existed for ERFE, hepcidin, food frequency, MBL, or daily training outcomes ( P > 0.05). Conclusions: A single nightly 200-mg dose of elemental iron was superior to a split dose for optimizing Hbmass changes at altitude in runners over an approximately 3-wk training camp.
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“recent evidence suggests that extra iron intake may be necessary for optimal erythropoietic adaptation to altitude (Garvican-Lewis et al., 2018, Hall et al., 2019).”
From Key Nutritional Considerations for Youth Winter Sports Athletes to Optimize Growth, Maturation and Sporting Development (2021) · cites this paper as Hall et al., 2019
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“At both sea level and altitude, the iron regulatory hormone, hepcidin, has been shown to increase in response to iron supplementation (16,28), exercise stress (6,7,29), inflammation (30), and/or underlying iron stores (31).”
Self-citationIdentification of erythroferrone as an erythroid regulator of iron metabolism
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“Though previously not explored in athletes at altitude, rodent data demonstrate that increases in ERFE can be used as a marker of erythropoiesis and subsequent suppression of the hepcidin response (15,37).”
Self-citationStoffel, N. U., Cercamondi, C. I., Brittenham, G., Zeder, C., Geurts-Moespot, A. J., Swinkels, D. W., Moretti, D., & Zimmermann, M. B. (2017) · The Lancet Haematology · doi:10.1016/s2352-3026(17)30182-5 · Cited by 435
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“(11) and the current study suggest that supplementing athletes with 200 mg of elemental iron per day (when exposed to ~2000 m of altitude) will likely optimize hematological adaptation to the stimulus, as measured by Hbmass outcomes (11,27).”
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Cited by
Iron considerations for the athlete: a narrative review
Sim, M., Garvican-Lewis, L. A., Cox, G. R., Govus, A., McKay, A. K. A., Stellingwerff, T., & Peeling, P. (2019) · European Journal of Applied Physiology · doi:10.1007/s00421-019-04157-y · Cited by 274
Self-citationHannon, M. P., Flueck, J. L., Gremeaux, V., Place, N., Kayser, B., & Donnelly, C. (2021) · Frontiers in Sports and Active Living · doi:10.3389/fspor.2021.599118 · Cited by 23
Metadata
- Authors
- HALL, R., PEELING, P., NEMETH, E., BERGLAND, D., MCCLUSKEY, W. T. P., & STELLINGWERFF, T.
- Affiliations
- Canadian Sport Institute Pacific, Vancouver & Victoria, British Columbia, CANADA;
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA;
- Hypo2 High Performance Sport Center, Flagstaff, AZ; and
- Venue
- Medicine & Science in Sports & Exercise
- Published
- 2019-04
- Volume
- 51
- Issue
- 4
- Pages
- 751-759
- ISSN
- 1530-0315
- 0195-9131
- Cited by
- 27
- References
- 5
- Language
- en
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