Abstract
Members of the military get inadequate sleep due to a variety of reasons. Reduced manning, extended work hours, shiftwork schedules that result in circadian misalignment – all of these factors contribute to the sleep debt and degraded alertness observed in much of the military population. The issue of watchstanding schedules, performance, and alertness is of critical importance to the US military and is the focus of the current study. Based on a sample of active duty military members (N=75), this study had two goals. First, to conduct a field-based monitoring of the sleep and performance of military personnel while performing their duties. Second, to create and validate optimal recommendations based on the results of this empirical study. Participants wore actigraphs over a two-week period, completed daily activity logs, and took three-minute reaction time tests before and after standing watch on their regular schedules. Participants worked on a 2-day on/2-day off schedule, either in 3-section 8-hour shifts, or 2-section 12-hour shifts. Although there were no significant differences in the sleep amounts between the two schedules, results showed that participants on 8-hr shifts had fewer errors and less variable reaction time performance than those working 12-hr shifts. The 8-hr group reported better sleep quality, too. Our results suggest that the 8-hour schedule is better than the 12-hour schedule in terms of sleep and performance but may be more difficult to be applied. This study clearly shows the difficulty of implementing a specific watchstanding schedule in operational environments overloaded with unplanned, and irregular operational duties.