Sleep of recruits throughout basic military training and its relationships with stress, recovery, and fatigue

Abstract

Objective Studies in basic military training (BMT) examining sleep are largely cross-sectional, and do not investigate relationships between sleep, stress, recovery and fatigue. The aims of this study were to (1a) quantify changes in recruits’ sleep quantity and quality over 12 weeks of BMT; (1b) quantify changes in recruits’ perceptions of stress, fatigue and recovery over BMT; and (2) explore relationships between sleep, and perceptions of stress, fatigue and recovery. Methods 45 recruits (37 male; 8 female, age: 25.2 ± 7.2 years, height: 176.2 ± 10.0 cm, mass: 76.8 ± 15.0 kg) wore ActiGraph GT9X’s for 12 weeks of BMT, collecting sleep duration, efficiency and awakenings. Subjective sleep quality, fatigue were measured daily, with stress and recovery measured weekly. Multi-level models assessed relationships between sleep, and stress, recovery, and fatigue. Results Objective daily means for sleep duration were 6.3 h (± 1.2 h) and 85.6% (± 5.5%) for sleep efficiency. Main effects were detected for all mean weekly values (p < 0.05). Sleep quality showed the strongest relationships with stress, recovery and fatigue. The best model to explain relationships between, stress, recovery and fatigue, included sleep quality, sleep duration, sleep efficiency and awakenings. Conclusions The reported mean sleep duration of 6.3 h per night may negatively impact training outcomes across BMT. Combining both subjective and objective measures of sleep best explained relationships between sleep metrics stress, fatigue and recovery. Perceived sleep quality was most strongly related to change in stress, recovery, or post-sleep fatigue.

Steps toward developing a comprehensive fatigue monitoring and mitigation solution: perspectives from a cohort of United States Naval Surface Force officers

“…For example, that more experienced officers were more likely to frequently provide recovery periods when fatigue was identified may have been related to a greater understanding of the ability or need to prioritize rest in different situations based on operational needs. Furthermore, consistent with previous studies of military service members, worse sleep quality predicted more fatigue [ 6 , 10 ].…”

“…Such factors can disrupt sleep and alertness if individuals’ daily schedules become misaligned with the timing signals generated by their internal circadian rhythms [ 7 , 8 ]. As a case in point, short sleep has consistently been observed aboard US Navy (USN) warships, whether measured using self-report surveys (mean ± standard deviation; 5.26 ± 1.23 hours) [ 6 ] or actigraphy (6.60 ± 1.01 hours) [ 9 ] and fatigue has been associated with several deadly and costly at-sea mishaps [ 10–13 ]. These prominent threats to safety, among other consequences of fatigue, underscore the need for an effective fatigue management system (i.e.…”

Factors Predicting Training Delays and Attrition of Recruits during Basic Military Training

“…This study was approved by the Department of Defence and Veteran’s Affairs Human Research Ethics Committee (021-17). An overview of activities completed during BMT has been previously described [ 32 , 33 ], while sleep duration for these recruits has also been reported [ 33 ]. Activities included training related to military skills and equipment, marksmanship, and combat manoeuvres, and culminated in a 10-day field training phase which involved sleep restriction, physical and cognitive demands, and outdoor sleeping and night activities (e.g., picket).…”

The predictive effect of basic military training and general health status on sleep quality

“…Although it has been known since time immemorial that different emotions can be experienced during initial active duty for training [6], it can be argued that these emotions can also affect other health factors such as mental and physical health and sleep quality. In a study, it was found that there were strong relationships between subjective sleep quality and stress, rest, and fatigue in initial active duty for training for 12 weeks [7]. In addition, soldiers, firefighters, correctional officers, and paramedics experience more mental health problems as they are exposed to more psychological traumatic events in their lives than other individuals [8].…”