Accommodating adolescent sleep-wake patterns: the effects of shifting the timing of sleep on training effectiveness.

STUDY OBJECTIVE: This study evaluated the effect of accommodating adolescent sleep-wake patterns by altering the timing of the major sleep period of US Army recruits. DESIGN: The quasi-experimental study compared recruits assigned to one of two training companies: one with a customary sleep regimen (20:30 to 04:30) while the other employed a phase-delayed sleep regimen (23:00 to 07:00), the latter aligning better with biologically driven sleep-wake patterns of adolescents. SETTING: The study was conducted during Basic Combat Training (BCT) at Fort Leonard Wood, Missouri. TRAINEES: The study included 392 trainees: 209 received the intervention, while 183 composed the Comparison group. MEASUREMENTS AND RESULTS: Demographic and psychophysiological measures were collected on all trainees. Weekly assessments of subjective fatigue and mood, periodic physical fitness, marksmanship scores, and attrition rates from BCT were studied. Actigraphy was collected on approximately 24% of trainees. Based on actigraphy, trainees on the phase-delayed sleep schedule obtained 31 m more sleep/night than trainees on the customary sleep schedule. The Intervention group reported less total mood disturbance relative to baseline. Improvements in marksmanship correlated positively with average nightly sleep during the preceding week when basic marksmanship skills were taught. No differences were seen in physical fitness or attrition rates. In contrast to the Intervention group, the Comparison group was 2.3 times more likely to experience occupationally significant fatigue and 5.5 times more likely to report poor sleep quality. CONCLUSIONS: Accommodating adolescent sleep patterns significantly improves mental health and performance in the training environment.

Sleep and fatigue issues in continuous operations: a survey of U.S. Army officers.

Forty-nine U.S. Army officers with recent combat experience were surveyed to assess their units' sleep patterns and to determine the tactics, techniques, and procedures used to counter the effects of sleep deprivation in their units. Despite Army policy requiring units to develop and implement sleep management plans, nearly 80% of the participants reported they had not been briefed on a sleep management plan during their most recent deployment. Over one half of the respondents reported that fatigue was a problem in their units. During high operational tempo (OPTEMPO), which occupied nearly half of their time in combat, participants report receiving only 4 hr of sleep daily. The vast majority of respondents (82.6%) reported feeling sleep-deprived at least occasionally while at high OPTEMPO. These findings have important implications for the operational readiness of all military units deployed to combat environments.

Longitudinal study of sleep patterns of United States Military Academy cadets.

STUDY OBJECTIVES: The study provided an opportunity to observe sleep patterns in a college-age population attending the United States Military Academy. DESIGN: This 4-year longitudinal study investigated sleep patterns of cadets. A stratified sample of 80 cadets had sleep patterns monitored using actigraphy for 8 months: one month in both fall and spring academic semesters over a 4-year period. SETTING: Data were collected at the United States Military Academy, West Point, NY. PARTICIPANTS: Participants were members of the class of 2007 (n˜1300) ranging in age from 17 to 22 when entering USMA. MEASUREMENTS AND RESULTS: A sample of the class (n=80) wore wrist activity monitors and completed activity logs for one month in fall and spring academic semesters for the 4-year period. On average over the 4 years, cadets slept<5.5 h on school nights. Cadets napped extensively, perhaps in an attempt to compensate for chronic sleep debt. Cadets slept more during fall than spring semesters. Male and female cadet sleep patterns varied dramatically, with males consistently receiving less sleep than females (˜21 m for nighttime sleep and ˜23 m for daily sleep). CONCLUSIONS: Cadet sleep at USMA is related to academic year, semester, season, sex, school day or weekend, and day of the week. These students suffer from chronic sleep debt. Restrictions imposed by the military academy limit the generalizability of the findings to other college age populations.

Sleep patterns of young men and women enrolled at the United States Military Academy: results from year 1 of a 4-year longitudinal study.

STUDY OBJECTIVES: Sleep patterns of young adults are different from those of other age groups.. This study examined sleep patterns of cadets during their first year at the United States Military Academy. DESIGN: This paper presents initial results of a 4-year longitudinal investigation into sleep patterns of college-age men and women. SETTING: Data were collected at the United States Military Academy, a 4-year undergraduate institution that develops men and women in 4 areas: intellectual, physical, military, and moral-ethical. PARTICIPANTS: Survey data were obtained from all members of the Class of 2007 (N approximately 1300), who ranged in age from 17 to 22 years. A stratified sample (n = 80) was selected to wear wrist-activity monitors. An additional 40 members of the junior and senior classes participated in the summer portion of the study. MEASUREMENTS AND RESULTS: Sleep patterns prior to entering the United States Military Academy were compared with patterns during cadet basic training and fall and spring semesters. Actigraphy data were recorded on a sample of the class (n = 80) for 50 days during cadet basic training and 30 days during fall and spring semesters. During cadet basic training, incoming cadets received 5 hours 40 minutes of sleep per night. During fall 2003 semester, these same cadets received 4 hours 50 minutes of sleep on school nights and 6 hours 32 minutes on weekends. Sleep received during spring 2004 semester was similar, with 5 hours 06 minutes on school nights and 6 hours 29 minutes on weekends. CONCLUSIONS: This first year of baseline data collection describes cadet sleep patterns and sets the stage to assess the effectiveness of follow-on interventions.