Acute carbohydrate ingestion does not influence the post-exercise iron-regulatory response in elite keto-adapted race walkers

Alannah K A McKay, Peter Peeling, David B Pyne, Marijke Welvaert, Nicolin Tee, Jill J Leckey, Avish P Sharma, Megan L R Ross, Laura A Garvican-Lewis, Rachel P L van Swelm, Coby M Laarakkers, Louise M Burke

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Abstract

Objectives: Adhering to a low carbohydrate (CHO) high fat (LCHF) diet can alter markers of iron metabolism in endurance athletes. This investigation examined the re-introduction of CHO prior to, and during exercise on the iron-regulatory response to exercise in a homogenous (in regard to serum ferritin concentration) group of athletes adapted to a LCHF diet. Design: Parallel groups design. Methods: Three weeks prior to the exercise trials, twenty-three elite race walkers adhered to either a CHO-rich (n = 14) or LCHF diet (n = 9). A standardised 19–25 km race walk was performed while athletes were still adhering to their allocated dietary intervention (Adapt). A second test was performed three days later, where all athletes were placed on a high CHO diet (CHO Restoration). Venous blood samples were collected pre-, post- and 3 h post-exercise and measured for interleukin-6 (IL-6) and hepcidin-25. Results: The post-exercise IL-6 increase was greater in LCHF (p < 0.001) during both the Adapt (LCHF: 13.1-fold increase; 95% CI: 5.6–23.0, CHO: 8.0-fold increase; 5.1–11.1) and CHO Restoration trials (LCHF: 18.5-fold increase; 10.9–28.9, CHO: 6.3-fold increase; 3.9–9.5); outcomes were not different between trials (p = 0.84). Hepcidin-25 concentrations increased 3 h post-exercise (p < 0.001), however, they did not differ between trials (p = 0.46) or diets (p = 0.84). Conclusions: The elevated IL-6 response in athletes adapted to a LCHF diet was not attenuated by an acute increase in exogenous CHO availability. Despite diet-induced differences in IL-6 response to exercise, post-exercise hepcidin levels were similar between diets and trials, indicating CHO availability has minimal influence on post-exercise iron metabolism.

Original languageEnglish
Pages (from-to)635-640
Number of pages6
JournalJournal of Science and Medicine in Sport
Volume22
Issue number6
DOIs
Publication statusPublished - 1 Jun 2019

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Walkers
Iron
Eating
Carbohydrates
Exercise
Diet
Athletes
Hepcidins
Interleukin-6
High Fat Diet
Ferritins

Cite this

McKay, Alannah K A ; Peeling, Peter ; Pyne, David B ; Welvaert, Marijke ; Tee, Nicolin ; Leckey, Jill J ; Sharma, Avish P ; Ross, Megan L R ; Garvican-Lewis, Laura A ; van Swelm, Rachel P L ; Laarakkers, Coby M ; Burke, Louise M. / Acute carbohydrate ingestion does not influence the post-exercise iron-regulatory response in elite keto-adapted race walkers. In: Journal of Science and Medicine in Sport. 2019 ; Vol. 22, No. 6. pp. 635-640.
@article{f61e6ab6ccda44b39c3d91b28732e838,
title = "Acute carbohydrate ingestion does not influence the post-exercise iron-regulatory response in elite keto-adapted race walkers",
abstract = "Objectives: Adhering to a low carbohydrate (CHO) high fat (LCHF) diet can alter markers of iron metabolism in endurance athletes. This investigation examined the re-introduction of CHO prior to, and during exercise on the iron-regulatory response to exercise in a homogenous (in regard to serum ferritin concentration) group of athletes adapted to a LCHF diet. Design: Parallel groups design. Methods: Three weeks prior to the exercise trials, twenty-three elite race walkers adhered to either a CHO-rich (n = 14) or LCHF diet (n = 9). A standardised 19–25 km race walk was performed while athletes were still adhering to their allocated dietary intervention (Adapt). A second test was performed three days later, where all athletes were placed on a high CHO diet (CHO Restoration). Venous blood samples were collected pre-, post- and 3 h post-exercise and measured for interleukin-6 (IL-6) and hepcidin-25. Results: The post-exercise IL-6 increase was greater in LCHF (p < 0.001) during both the Adapt (LCHF: 13.1-fold increase; 95{\%} CI: 5.6–23.0, CHO: 8.0-fold increase; 5.1–11.1) and CHO Restoration trials (LCHF: 18.5-fold increase; 10.9–28.9, CHO: 6.3-fold increase; 3.9–9.5); outcomes were not different between trials (p = 0.84). Hepcidin-25 concentrations increased 3 h post-exercise (p < 0.001), however, they did not differ between trials (p = 0.46) or diets (p = 0.84). Conclusions: The elevated IL-6 response in athletes adapted to a LCHF diet was not attenuated by an acute increase in exogenous CHO availability. Despite diet-induced differences in IL-6 response to exercise, post-exercise hepcidin levels were similar between diets and trials, indicating CHO availability has minimal influence on post-exercise iron metabolism.",
keywords = "LCHF diet, Iron metabolism, Ferritin, Hepcidin, interleukin 6, Race-walkers, Interleukin-6",
author = "McKay, {Alannah K A} and Peter Peeling and Pyne, {David B} and Marijke Welvaert and Nicolin Tee and Leckey, {Jill J} and Sharma, {Avish P} and Ross, {Megan L R} and Garvican-Lewis, {Laura A} and {van Swelm}, {Rachel P L} and Laarakkers, {Coby M} and Burke, {Louise M}",
note = "Copyright {\circledC} 2018. Published by Elsevier Ltd.",
year = "2019",
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doi = "10.1016/j.jsams.2018.12.015",
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McKay, AKA, Peeling, P, Pyne, DB, Welvaert, M, Tee, N, Leckey, JJ, Sharma, AP, Ross, MLR, Garvican-Lewis, LA, van Swelm, RPL, Laarakkers, CM & Burke, LM 2019, 'Acute carbohydrate ingestion does not influence the post-exercise iron-regulatory response in elite keto-adapted race walkers', Journal of Science and Medicine in Sport, vol. 22, no. 6, pp. 635-640. https://doi.org/10.1016/j.jsams.2018.12.015

Acute carbohydrate ingestion does not influence the post-exercise iron-regulatory response in elite keto-adapted race walkers. / McKay, Alannah K A; Peeling, Peter; Pyne, David B; Welvaert, Marijke; Tee, Nicolin; Leckey, Jill J; Sharma, Avish P; Ross, Megan L R; Garvican-Lewis, Laura A; van Swelm, Rachel P L; Laarakkers, Coby M; Burke, Louise M.

In: Journal of Science and Medicine in Sport, Vol. 22, No. 6, 01.06.2019, p. 635-640.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Acute carbohydrate ingestion does not influence the post-exercise iron-regulatory response in elite keto-adapted race walkers

AU - McKay, Alannah K A

AU - Peeling, Peter

AU - Pyne, David B

AU - Welvaert, Marijke

AU - Tee, Nicolin

AU - Leckey, Jill J

AU - Sharma, Avish P

AU - Ross, Megan L R

AU - Garvican-Lewis, Laura A

AU - van Swelm, Rachel P L

AU - Laarakkers, Coby M

AU - Burke, Louise M

N1 - Copyright © 2018. Published by Elsevier Ltd.

PY - 2019/6/1

Y1 - 2019/6/1

N2 - Objectives: Adhering to a low carbohydrate (CHO) high fat (LCHF) diet can alter markers of iron metabolism in endurance athletes. This investigation examined the re-introduction of CHO prior to, and during exercise on the iron-regulatory response to exercise in a homogenous (in regard to serum ferritin concentration) group of athletes adapted to a LCHF diet. Design: Parallel groups design. Methods: Three weeks prior to the exercise trials, twenty-three elite race walkers adhered to either a CHO-rich (n = 14) or LCHF diet (n = 9). A standardised 19–25 km race walk was performed while athletes were still adhering to their allocated dietary intervention (Adapt). A second test was performed three days later, where all athletes were placed on a high CHO diet (CHO Restoration). Venous blood samples were collected pre-, post- and 3 h post-exercise and measured for interleukin-6 (IL-6) and hepcidin-25. Results: The post-exercise IL-6 increase was greater in LCHF (p < 0.001) during both the Adapt (LCHF: 13.1-fold increase; 95% CI: 5.6–23.0, CHO: 8.0-fold increase; 5.1–11.1) and CHO Restoration trials (LCHF: 18.5-fold increase; 10.9–28.9, CHO: 6.3-fold increase; 3.9–9.5); outcomes were not different between trials (p = 0.84). Hepcidin-25 concentrations increased 3 h post-exercise (p < 0.001), however, they did not differ between trials (p = 0.46) or diets (p = 0.84). Conclusions: The elevated IL-6 response in athletes adapted to a LCHF diet was not attenuated by an acute increase in exogenous CHO availability. Despite diet-induced differences in IL-6 response to exercise, post-exercise hepcidin levels were similar between diets and trials, indicating CHO availability has minimal influence on post-exercise iron metabolism.

AB - Objectives: Adhering to a low carbohydrate (CHO) high fat (LCHF) diet can alter markers of iron metabolism in endurance athletes. This investigation examined the re-introduction of CHO prior to, and during exercise on the iron-regulatory response to exercise in a homogenous (in regard to serum ferritin concentration) group of athletes adapted to a LCHF diet. Design: Parallel groups design. Methods: Three weeks prior to the exercise trials, twenty-three elite race walkers adhered to either a CHO-rich (n = 14) or LCHF diet (n = 9). A standardised 19–25 km race walk was performed while athletes were still adhering to their allocated dietary intervention (Adapt). A second test was performed three days later, where all athletes were placed on a high CHO diet (CHO Restoration). Venous blood samples were collected pre-, post- and 3 h post-exercise and measured for interleukin-6 (IL-6) and hepcidin-25. Results: The post-exercise IL-6 increase was greater in LCHF (p < 0.001) during both the Adapt (LCHF: 13.1-fold increase; 95% CI: 5.6–23.0, CHO: 8.0-fold increase; 5.1–11.1) and CHO Restoration trials (LCHF: 18.5-fold increase; 10.9–28.9, CHO: 6.3-fold increase; 3.9–9.5); outcomes were not different between trials (p = 0.84). Hepcidin-25 concentrations increased 3 h post-exercise (p < 0.001), however, they did not differ between trials (p = 0.46) or diets (p = 0.84). Conclusions: The elevated IL-6 response in athletes adapted to a LCHF diet was not attenuated by an acute increase in exogenous CHO availability. Despite diet-induced differences in IL-6 response to exercise, post-exercise hepcidin levels were similar between diets and trials, indicating CHO availability has minimal influence on post-exercise iron metabolism.

KW - LCHF diet

KW - Iron metabolism

KW - Ferritin

KW - Hepcidin

KW - interleukin 6

KW - Race-walkers

KW - Interleukin-6

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UR - http://www.mendeley.com/research/acute-carbohydrate-ingestion-not-influence-postexercise-ironregulatory-response-elite-ketoadapted-ra

U2 - 10.1016/j.jsams.2018.12.015

DO - 10.1016/j.jsams.2018.12.015

M3 - Article

VL - 22

SP - 635

EP - 640

JO - Australian Journal of Science and Medicine in Sport

JF - Australian Journal of Science and Medicine in Sport

SN - 1440-2440

IS - 6

ER -