Hormonal contraceptive use and physical performance, body composition, and musculoskeletal injuries during military training

O'Leary, Thomas J., Evans, Hope A., Close, Marie-Elise O., Izard, Rachel M., Walsh, Neil P., Coombs, Charlotte V., Carswell, Alexander T., Oliver, Samuel J., Tang, Jonathan C. Y., Fraser, William D. and Greeves, Julie P. (2025) Hormonal contraceptive use and physical performance, body composition, and musculoskeletal injuries during military training. Medicine and Science in Sports and Exercise, 57 (3). pp. 613-624. 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:	Data Availability Statement: All data and code are available from the corresponding author pending approval of public release from UK Ministry of Defence. Funding information: This study was funded by the UK Ministry of Defence (Army).
Uncontrolled Keywords:	bone,endurance,muscle,musculoskeletal injury,oestrogens,progestogen,orthopedics and sports medicine,physical therapy, sports therapy and rehabilitation ,/dk/atira/pure/subjectarea/asjc/2700/2732
Faculty \ School:	Faculty of Medicine and Health Sciences > Norwich Medical School
UEA Research Groups:	Faculty of Medicine and Health Sciences > Research Centres > Lifespan Health Faculty of Medicine and Health Sciences > Research Groups > Musculoskeletal Medicine Faculty of Medicine and Health Sciences > Research Centres > Metabolic Health
Related URLs:	http://www.scopus.com/inward/record.url?...
Depositing User:	LivePure Connector
Date Deposited:	16 Oct 2024 09:30
Last Modified:	17 Feb 2025 10:30
URI:	https://ueaeprints.uea.ac.uk/id/eprint/97036
DOI:	10.1249/MSS.0000000000003588

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