CHANGES IN BODY COMPOSITION AND PHYSICAL PERFORMANCE OF SOLDIERS DURING MANDATORY MILITARY SERVICE

Abstract

Introduction: The entry of 18-19-year-old youth into the Armed Forces through compulsory military service (CMS) promotes an abrupt lifestyle transition, characterized by a rigorous physical and operational routine. Objective: To analyze changes in body composition and physical performance in recruit soldiers subjected to nine months (36 weeks) of military instruction and Military Physical Training (MPT). Methods: A longitudinal study conducted with a platoon of 21 newly incorporated soldiers in a combat engineering battalion in Cachoeira do Sul-RS. Body composition (body mass, height, and fat percentage using the Jackson and Pollock 3-skinfold protocol with a Sanny® caliper and a Líder® scale) and functional physical performance were evaluated using the Physical Fitness Test (PFT) at three moments (diagnostic, formative, and summative), which included the 12-minute run, push-ups, pull-ups, and sit-ups. Results: At the end of 36 weeks, 85.71% of the soldiers presented a statistically significant reduction in body fat percentage, with an average decrease from to (). Additionally, 100% of the sample obtained a significant increase in lean mass, rising from to (). Regarding functional performance, a significant reduction was observed in the overall "Insufficient" rating in the PFT (from 57.1% in the first evaluation to 38.0% in the last), accompanied by a marked improvement in both aerobic and neuromuscular muscle strength and endurance indices. Conclusion: The first year of military instruction and periodized MPT promoted highly beneficial neuromuscular and cardiorespiratory adaptations, leading to a healthy body recomposition process and optimizing the operational physical readiness of the combatants.