THE WINTER CONTINGENCY- A SLEEP STUDY OF ARMY AIRCREWS OPERATING IN THE ARCTIC WINTER AND THE EFFECTS OF LIGHT EXPOSURE

• Main Author: Crook, Jeffery W.
• Other Authors: Nita Lewis Shattuck, Operations Research (OR), Matsangas, Panagiotis
• Format: Thesis
• Language: unknown
• Published: Monterey, CA; Naval Postgraduate School 2023
• Subjects: sleep; aircrew; Army; high energy visible; HEV; profile of mood states; POMS; Beck’s depression inventory; BDI-II; Arctic; Alaska
• Online Access: https://hdl.handle.net/10945/72698

This study investigated the sleep quality, sleep duration, and mood of soldiers operating in a winter Arctic environment, and the effects of high energy visible (HEV) light exposure. Twenty participants (19 males, one female) at Fort Wainwright, Alaska were recruited to participate in a study. The data collection took place over seven weeks during the winter months. Participants wore sleep-tracking Ōura rings throughout the study to assess sleep and wore HEV light-emitting glasses for 30 to 60 minutes upon awakening prior to the start of their duty day; HEV light canvases were also installed in common work areas. Our findings indicated that participants received adequate durations of sleep throughout the study and we saw no significant change (p = 0.356) in sleep durations between the baseline (MD=7.2, IQR=1.78) and light treatment phases of the study (MD=7.07, IQR=1.93). However, the quality of participants’ sleep may have been lacking as indicated by participant responses on questionnaires. We found significant improvement for profile of mood states (POMS) depressive symptoms (p = 0.039), fatigue (p = 0.074), confusion (p = 0.057) and Beck’s depression inventory (BDI-II) (p = 0.049) measurements when comparing mid-study and end-of-study questionnaires. The study could not control for the natural increase in daylight throughout the study, which may have played a role in the improvement in mood. Approved for public release. Distribution is unlimited. Major, United States Army