Publications by authors named "J P Greeves"
Objectives: Automated immunoassays for 1,25-dihydroxyvitamin D (1,25(OH)D) have increased the use of serum measurements in clinical and research settings, but disagreement with LC-MS/MS methods remains an issue.
Methods: In this study, we examined this problem using samples obtained from healthy young adults, n=80, mean age 21.7 (18-32) years, and a large cohort of paediatric samples, n=422, mean age 7.
British Army basic training (BT) and initial trade training (ITT) enable personnel to develop role-related physical capability to perform in-service job-roles. The study aimed to compare physical performance of trainees (completing ITT) and trained soldiers, on a series of gym-based fitness tests and representative military tasks. A total of 316 British Army personnel [68 trainees (63 men: 22 ± 3 years, 71.
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- This study investigated how psychological and physical stress affects the reproductive and adrenal hormone systems in men and women during military training.
- Results showed that women exhibited greater HPA axis responses (higher cortisol levels) compared to men, while men had higher gonadotrophin responses than women.
- Notably, the findings indicate that women experienced a more significant suppression of reproductive hormone function during stress, contributing to the understanding of how sex differences influence stress responses in high-demand environments.
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.
View Article and Find Full Text PDFBackground: Women of reproductive age experience cyclical variation in the female sex steroid hormones 17β-estradiol and progesterone during the menstrual cycle that is attenuated by some hormonal contraceptives. Estrogens perform a primary function in sexual development and reproduction but have nonreproductive effects on bone, muscle, and sinew tissues (ie, ligaments and tendons), which may influence injury risk and physical performance.
Objective: The purpose of the study is to understand the effect of the menstrual cycle and hormonal contraceptive use on bone and calcium metabolism, and musculoskeletal health and performance.