Sex differences in physical performance, sleep, and psychological responses to long‐term, arduous military training

The U.S. Army Ranger Training Course (RTC) challenges candidates physically and mentally over 61+ days across varied environments. Psychological measures of resilience, grit, sleep, and physical performance have been investigated during RTC; however, whether those associations differ between sexes has not, despite sex integration occurring in 2015. 37 participants (10F, 27 ± 3y; 27 M, 25 ± 4y; mean ± SD) completed measurements of strength and power (isometric mid-thigh pull (IP) and standing long jump (SLJ)), self-reported outcomes of sleep (Pittsburgh Sleep Quality Index (PSQI)), resilience (CD-RISC-10), and grit (GRIT-S) before (BL) and after RTC (POST). Males displayed greater absolute measures of IP and SLJ at BL and POST than females (both, p < 0.0001); however, both sexes showed similar deficits POST. Sleep declined over time, with PSQI scores increasing (p < 0.001), including daytime dysfunction, duration, and quality deteriorating similarly for both sexes (all p < 0.05). GRIT-S and CD-RISC10 scores started and remained high, with no change over time nor differences by sex. Large deficits in strength and sleep were observed in a mixed-sex sample of military personnel undergoing strenuous 61+ day elite military training. Although males displayed greater absolute strength and power than females at both time points, no differences in performance decrements, sleep, or psychological factors were observed over the course.