The effect of sex and protein supplementation on bone metabolism during a 36-hour military field exercise in energy deficit

O'Leary, Thomas J., Coombs, Charlotte V., Edwards, Victoria C., Blacker, Sam D., Knight, Rebecca L., Koivula, Fiona N., Tang, Jonathan C. Y. ORCID: https://orcid.org/0000-0001-6305-6333, Fraser, William D., Wardle, Sophie L. and Greeves, Julie P. (2023) The effect of sex and protein supplementation on bone metabolism during a 36-hour military field exercise in energy deficit. Journal of Applied Physiology, 134 (6). pp. 1481-1495. ISSN 8750-7587

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Abstract

This study investigated sex differences in, and the effect of protein supplementation on, bone metabolism during a 36-hour military field exercise. Forty-four British Army Officer cadets (14 women) completed a 36-hour field exercise. Participants consumed their habitual diet (n = 14 women [Women] and n = 15 men [Men Controls]) or the habitual diet and an additional 46.6 g·d–1 protein in men (n = 15 men [Men Protein]). Women and Men Protein were compared with Men Controls to examine the effect of sex and protein supplementation. Circulating markers of bone metabolism were measured before, 24 hours after (post-exercise), and 96 hours after (recovery) the field exercise. βCTX and cortisol were not different between time-points or Women and Men Controls (p ≥ 0.094). PINP decreased from baseline to post-exercise (p < 0.001) and recovery (p < 0.001) in Women and Men Controls. PTH increased from baseline to post-exercise (p = 0.006) and decreased from post-exercise to recovery (p = 0.047) in Women and Men Controls. Total 25(OH)D increased from baseline to post-exercise (p = 0.038) and recovery (p < 0.001) in Women and Men Controls. Testosterone decreased from baseline to post-exercise (p < 0.001) and recovery (p = 0.007) in Men Controls, but did not change for Women (all p = 1.000). Protein supplementation in men had no effect on any marker. Men and women experience similar changes to bone metabolism—decreased bone formation and increased PTH—following a short field exercise. Protein had no protective effect likely because of the energy deficit.

Item Type:	Article
Faculty \ School:	Faculty of Medicine and Health Sciences > Norwich Medical School
Depositing User:	LivePure Connector
Date Deposited:	19 May 2023 08:32
Last Modified:	31 May 2023 11:30
URI:	https://ueaeprints.uea.ac.uk/id/eprint/92103
DOI:	10.1152/japplphysiol.00106.2023

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