Psychophysiological stress and resilience responses to military training and their associations with injury and attrition status among male and female personnel

Psychological and physiological stress may be influenced by military training and responses may vary based on sex. Baseline psychological (Perceived Stress Scale (PSS) and Connor-Davidson Resilience Scale (CD-RISC)) and physiological (serum cortisol and dehydroepiandrosterone (DHEA)) measures of stress and resilience were compared and assessed for their relationship with injury and attrition status between male and female candidates participating in Marine Corps Officer Candidates School (OCS). Changes over time were assessed in those who completed OCS. Two-way independent measures ANOVAs (sex*group) compared baseline measures between sexes and injured/non-injured candidates, and completers/non-completers. Two-way mixed measures ANOVAs (time*sex) assessed changes over time in completers. At baseline (24.6 ± 3.2 yrs; 25.3 ± 2.3 kg/m2; 22.2 % female), PSS and cortisol were higher in females than males. Similarly, PSS and cortisol were higher, but DHEA was lower, in those who did not complete training. In completers, significant interaction effects for CD-RISC, cortisol, and DHEA were observed. CD-RISC did not change over time in males but decreased in females. Cortisol and DHEA decreased over time in both sexes, but to a greater extent in females than males. During OCS, PSS increased over time, and females scored higher than males. Female candidates observed reduced resilience and neuroendocrine concentrations and greater perceived stress than males, indicating a sex difference in coping ability and greater physiological burden to military training. Baseline stress measures may also serve as risk factors for attrition.