Body Composition Modifications Due to the "Search, Rescue and Survival Training" in Male Military Firefighter Cadets

To train and prepare cadets for a career as firefighters in Rio de Janeiro, the second-year students of the Officers Training Course are submitted to a Search, Rescue, and Survival Training (SRST) course, which is characterized by long periods of high physical exertion and sleep restriction during a 9-day instruction module, and food restriction during a 7-day survival module. The present study investigated changes in the body composition of 39 male cadets submitted to SRST during training and 4 weeks of recovery with no restrictions in food consumption.

Each cadet was evaluated by anthropometric measurements at six time points: pre-SRST; after the first module; after the second module; and after 1, 2, and 4 weeks of recovery. Measurements included body girths and skinfolds, to estimate trunk (chest and waist) and limbs (arm and thigh) dimensions, as well as body composition. Repeated measures ANOVA and Friedman test were applied (depending on each data distribution).

Statistically significant decreases in body weight (76.2; 69.8-87.2 to 63.9; 58.9-73.5 kg) and fat free mass (FFM, 69.2; 63.7-77.2 to 60.1; 56.2-68.0 kg) were observed following the second module of SRST. Following a single week of recovery, the FFM returned to pre-SRST values. Body weight returned to pre-training levels in 2 weeks. Body fat percentage and mass also significantly decreased during SRST (9.0; 7.7-12.3 to 6.5; 5.1-9.3% and 6.9; 5.6-10.0 to 6.9; 5.6-10.0 kg, respectively), which showed a slower and more gradual recovery that reached pre-SRST values after 4 weeks. The girths of arm, thigh, chest and waist significantly decreased due to SRST. The girths of the limbs (arm and thigh) returned to pre-training values after one month of recovery, while the girths of the trunk (chest and waist) did not return to pre-SRST values during the study period.

The findings suggest that men who experience periods of high energy demands and sleep restriction followed by a period of food restriction will endure unavoidable physical consequences that can be mostly reversed by a 1-month recovery.