The physiological and performance consequences of the Australian Special Forces selection course
Date of Award
2024
Document Type
Thesis
Publisher
Edith Cowan University
Degree Name
Doctor of Philosophy
School
School of Medical and Health Sciences
First Supervisor
Greg Haff
Second Supervisor
Kristina Kendall
Abstract
Special Forces (SF) soldiers are the most elite element of military forces, who have undergone rigorous training in order to prepare them for a wide array of specialised missions. In Australia, entry into the SF is determined through the highly competitive SF Selection Course (SF-SC), which is a gruelling program involving extreme physical demands, psychological stress, and restricted access to sleep and nutrition. The stressors involved in arduous military training events such as the SF-SC can result in significant losses of fat mass and lean mass, disruption to hormonal homeostasis, and significant decreases in neuromuscular capacity, which can potentially increase injury risk and impair operational readiness. Therefore, it is crucial that those working with these individuals understand the magnitude of the deficits caused by training, and appreciate the time required for recovery following this type of training.
The aim of this thesis was to comprehensively investigate the physiological and performance repercussions of the SF-SC. This aim was achieved through the completion of three studies. The first study was used to evaluate the validity of wearable activity monitors for estimating energy expenditure during military training. This was preliminary study to determine whether wearable activity monitors could be utilised to assess the energetic demands of the SF-SC, however none of the devices tested met the accuracy requirements for valid energy expenditure estimation in this context.
Study two was used to investigate the physiological impact of the SF-SC, examining energy expenditure and dietary intake, as well as the changes in body composition, hormonal status, and resting metabolic rate induced by the course. Furthermore, this study monitored the recovery of these variables over an eight-week period following course completion. This study highlighted the substantial energy deficit associated with the SF-SC and revealed significant losses of fat mass and lean mass, significant changes in hormone concentrations, and a significant decrease in resting metabolic rate. While most physiological parameters returned to baseline levels within one to three weeks post-course, IGF-I concentration remained suppressed at eight weeks following the course, demonstrating prolonged recovery.
The final study was used to examine the impact of the SF-SC on physical performance outcomes, such as changes in strength and power generating capacity, and the time-course of recovery following the course. The combined stresses involved in the SF-SC resulted in substantial decreases in strength and power. All strength variables had returned to baseline levels by one week post course, whereas power variables required three weeks to fully recover.
Collectively, these studies provide a comprehensive overview of the acute physiological and performance toll exerted by the SF-SC and the subsequent recovery trajectory. These insights not only contribute to a deeper understanding of the physical demands placed on SF candidates but also inform the development of optimized training and recovery protocols to ensure the sustained operational readiness and health of these elite operators.
DOI
10.25958/5x90-ry26
Access Note
Access to this thesis is embargoed until 15th June 2026
Recommended Citation
Uphill, A. (2024). The physiological and performance consequences of the Australian Special Forces selection course. Edith Cowan University. https://doi.org/10.25958/5x90-ry26