Objectives: To investigate: (i) the chronicity and phasic variability of sleep patterns and restriction in recruits during basic military training (BMT); and (ii) identify subjective sleep quality in young adult recruits prior to entry into BMT. Design: Prospective observational study. Methods: Sleep was monitored using wrist-worn actigraphy in Army recruits (n = 57, 18–43 y) throughout 12-weeks of BMT. The Pittsburgh Sleep Quality Index (PSQI) was completed in the first week of training to provide a subjective estimate of pre-BMT sleep patterns. A mixed-effects model was used to compare wee...