Can Physiological and Psychological Factors Predict Dropout from Intense 10-Day Winter Military Survival Training?

Abstract

Background: In the military context, high levels of physiological and psychological stress together can compromise individual’s ability to complete given duty or mission and increase dropout rates. The purpose of this study was to investigate if baseline physical fitness, body composition, hormonal and psychological factors could predict dropout from a 10-day intense winter military survival training. Methods: 69 conscripts volunteered to participate in the study. Physical fitness (muscle strength and power, muscle endurance, and aerobic fitness), body composition and hormonal variables (BDNF, testosterone, cortisol, SHBG, DHEAS, IGF-1) together with self-reported psychological factors (short five personality, hardiness, sense of coherence, stress, depression) were assessed prior the survival training. Results: During the survival training, 20 conscripts (29%) dropped out. Baseline aerobic fitness (hazard ratio, HR: 0.997, 95% CI: 0.994–0.999, p = 0.006) and serum cortisol (HR: 1.0006, 95% CI: 1.001–1.011, p = 0.017) predicted dropout in Cox regression model. Each 10 m increase in the 12 min running test decreased the risk for dropout by 3%. Conclusion: Although most of the physiological and psychological variables at the baseline did not predict dropout during a short-term winter survival military training, baseline information of aerobic fitness and serum cortisol concentration may be useful to target support for individuals at higher potential risk for dropout.

Changes in Body Composition, Energy Metabolites and Electrolytes During Winter Survival Training in Male Soldiers

“…Thus, more accurate studies are needed to clarify protein and substrate metabolism during energy deficit. A high number of dropouts is typical for arduous training ( Vaara et al, 2020 ), but by using a mixed statistical model, we were able to use the maximum number of observations. Despite the high dropout rate, an adequate number of participants finished the survival training in both groups.…”

“…Self-reported sleeping times varied between 0.5 and 4 h per day in the field ( Vaara et al, 2020 ). In the garrison and during the recovery period, 7–8 h of sleep per day was possible.…”

“…During the recovery period the participants had light supervised physical activity (ball games, stretching) and various psychological therapy sessions. Self-reported sleeping times varied between 0.5 and 4 h per day in the field (Vaara et al, 2020). In the garrison and during the recovery period, 7-8 h of sleep per day was possible.…”

“…The mean temperature varied between −0.3 • C and −4.7 • C. The average depth of snow was between 80 and 100 cm. Overall description of the study protocol and field conditions has been published previously (Vaara et al, 2020).…”

Cinética do eixo GH/IGF-I em militares da Força Aérea Brasileira durante instrução de sobrevivência na selva

“…Em um treinamento militar de sobrevivência no inverno, as variações na cinética do eixo GH/IGF-I pouco influenciaram a permanência do combatente e o sucesso do exercício (VAARA et al, 2020). Entretanto, tendo em vista que, durante a Instrução de Sobrevivência na Selva, os militares envolvidos pouco se alimentaram (caldo de peixe e pequenos frutos), necessitaram realizar tarefas desgastantes (confecção de abrigos, limpeza da área, coleta de lenha, confecção de porto e armadilhas) e a variedade de agentes estressores disponíveis na selva amazônica, a supressão do eixo, conforme o estudo de Friedl et al(2000), foi uma hipótese confirmada.…”