TY - JOUR

T1 - Hormonal contraceptive use and physical performance, body composition, and musculoskeletal injuries during military training

AU - O'Leary, Thomas J

AU - Evans, Hope

AU - Close, Marie-Elise

AU - Izard, Rachel M

AU - Walsh, Neil

AU - Coombs, Charlotte

AU - Carswell, Alexander

AU - Oliver, Sam

AU - Tang, Jonathan C Y

AU - Fraser, William

AU - Greeves, Julie P

PY - 2024/10/11

Y1 - 2024/10/11

N2 - 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.

AB - 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.

M3 - Article

JO - Medicine and Science in Sports and Exercise

JF - Medicine and Science in Sports and Exercise

SN - 0195-9131

ER -