Hormonal Contraceptive Use and Physical Performance, Body Composition, and Musculoskeletal Injuries during Military Training

O'Leary, TJ, Evans, HA, Close, MEO, Izard, RM, Walsh, NP, Coombs, CV, Carswell, AT, Oliver, SJ, Tang, JCY, Fraser, WD and Greeves, JP (2024) Hormonal Contraceptive Use and Physical Performance, Body Composition, and Musculoskeletal Injuries during Military Training. Medicine & Science in Sports & Exercise. ISSN 0195-9131

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Abstract

Purpose: To investigate associations between hormonal contraceptive use and physical performance, body composition, and musculoskeletal injuries in basic military training. Methods: Female British Army recruits (n = 450) were grouped as non-users (n = 182), combined oral contraceptive users (COCP; n = 184), or progestin-only users (POC; n = 144). Physical performance (2.4 km run, lift strength, leg power), body composition, iron and vitamin D status, and bone metabolism were measured at the start (week 1) and end (week 13) of training. Lower body musculoskeletal injuries were recorded from medical records. Results: Training decreased 2.4 km run time (-3.7%) and fat mass (-9.6%), and increased lift strength (4.5%), leg power (1.5%), lean mass (5.4%), and whole-body (0.9%), arms (1.8%), and legs (1.4%) aBMD (p ≤ 0.015); the training response was not different between groups (p ≥ 0.173). Lift strength was lower in COCP users than non-users (p = 0.044). Whole-body, trunk, and legs aBMD were lower in POC users than non-users and/or COCP users (p ≤ 0.041). There were no associations between hormonal contraceptive use and musculoskeletal or bone stress injury (p ≥ 0.429). Training did not change ferritin (p = 0.968), but decreased haemoglobin and total 25(OH)D, and increased PTH, βCTX, and PINP (p ≤ 0.005); the training response was not different between groups (p ≥ 0.368). Total 25(OH)D was higher, and βCTX and PINP were lower, in COCP users than non-users and POC users; PTH was lower in COCP users than non-users, and; βCTX and PINP were higher in POC users than non-users (p ≤ 0.017). Conclusions: Hormonal contraceptive use was not associated with performance or injury outcomes in military training.

Item Type:	Article
Additional Information:	This is a pre-copyedited, author-produced version of an article accepted for publication in Medicine & Science in Sports & Exercise. The published version of record O’Leary, Thomas J.1,2; Evans, Hope A.1; Close, Marie-Elise O.1; Izard, Rachel M.3; Walsh, Neil P.4; Coombs, Charlotte V.1; Carswell, Alexander T.5; Oliver, Samuel J.6; Tang, Jonathan C. Y.5,7; Fraser, William D.5,7; Greeves, Julie P.1,2,5. Hormonal Contraceptive Use and Physical Performance, Body Composition, and Musculoskeletal Injuries during Military Training. Medicine & Science in Sports & Exercise ():10.1249/MSS.0000000000003588, November 6, 2024. | DOI: 10.1249/MSS.0000000000003588 is available online at: https://doi.org/10.1249/mss.0000000000003588
Uncontrolled Keywords:	Prevention; Physical Injury - Accidents and Adverse Effects; 1106 Human Movement and Sports Sciences; 1116 Medical Physiology; 1117 Public Health and Health Services; Sport Sciences
Subjects:	R Medicine > RC Internal medicine > RC1200 Sports Medicine U Military Science > U Military Science (General)
Divisions:	Sport and Exercise Sciences
Publisher:	Lippincott, Williams & Wilkins
Date of acceptance:	11 October 2024
Date Deposited:	14 Jan 2025 10:45
Last Modified:	14 Jan 2025 11:00
DOI or ID number:	10.1249/MSS.0000000000003588
URI:	https://researchonline.ljmu.ac.uk/id/eprint/25260

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