Impact of a Special Operations Forces Basic Training on Body Composition and Energy Expenditure

Area of Science:

• Exercise Physiology
• Sports Science
• Military Performance

Background:

• The Belgian Special Operations Regiment's 8-week Special Forces Basic Course follows initial military training.
• This study aimed to quantify energy expenditure and body composition shifts during this demanding course.

Purpose of the Study:

• To estimate energy expenditure during the Special Forces Basic Course.
• To assess changes in body composition, including weight, body fat, and muscle mass, in candidates undergoing the course.

Main Methods:

• Body composition was measured using a multi-frequency bioimpedance analysis at baseline and endpoint.
• Energy expenditure was estimated using triaxial accelerometers worn by 41 participants.
• Statistical significance was determined using t-tests, with effect size calculated using Cohen's d.

Main Results:

• 88 of 126 participants completed the course.
• Completers showed a significant decrease in body weight (78.3 to 76.4 kg) and body fat (3.1 kg, P=0.01), with a significant increase in muscle mass (1.2 kg, P=0.01).
• Mean total energy expenditure was 4,088 kcal/day, with significant reductions in body fat percentage (15.3% to 11.6%).

Conclusions:

• The Special Forces Basic Course creates a hypo-energetic environment for tactical athletes.
• Future research should explore the effects of increased energy intake on body composition in this population.