Sleep duration and physical performance during a 6‐week military training course

Abstract

Summary Sleep is vital in influencing effective training adaptations in the military. This study aimed to assess the relationship between sleep and changes in physical performance over 6 weeks of military training. A total of 22 officer‐trainees (age: 24 ± 5 years) from the New Zealand Defence Force were used for this prospective cohort study. Participants wore wrist‐actigraphs to monitor sleep, completed subjective wellbeing questionnaires weekly, and were tested for: 2.4‐km run time‐trial, maximum press‐up and curl‐ups before and after 6 weeks of training. Average sleep duration was calculated over 36 nights (6:10 ± 0:28 hr:min), and sleep duration at the mid‐point (6:15 hr:min) was used to stratify the trainees into two quantile groups (UNDERS: 5:51 ± 0:29 hr:min, n = 11) and (OVERS: 6:27 ± 0:09 hr:min, n = 11). There were no significant group × time interactions for 2.4‐km run, press‐ups or curl‐ups (p > .05); however, small effects were observed in favour of OVERS for 2.4‐km run (59.8 versus 44.9 s; d = 0.26) and press‐ups (4.7 versus 3.2 reps; d = 0.45). Subjective wellbeing scores resulted in a significant group × time interaction (p < .05), with large effect sizes in favour of the OVERS group for Fatigue in Week 1 (d = 0.90) and Week 3 (d = 0.87), and Soreness in Week 3 (d = 1.09) and Week 4 (d = 0.95). Sleeping more than 6:15 hr:min per night over 6 weeks was associated with small benefits to aspects of physical performance, and moderate to large benefits on subjective wellbeing measures when compared with sleeping < 6:15 hr:min.

Under Pressure: The Chronic Effects of Lower-Body Compression Garment Use during a 6-Week Military Training Course

“…During the study period, trainees completed a psychological questionnaire at the completion of each week on a Monday morning in a class prior to the next week commencing, as used previously [ 27 ]. The questionnaire was individually completed via a paper-based form, and assessed each trainee’s general muscle soreness and sleep quality on a five-point scale of 1 to 5 with 0.5 point increments (5 = very good, 4 = good, 3 = normal, 2 = poor, 1 = very poor).…”

Operation early‐bird: Investigating altered light exposure in military barracks on sleep and performance—a placebo‐controlled study

“…The Micro Motionlogger actigraph uses a tri‐axial accelerometer that has also been validated against PSG, and distinguishes sleep from wakefulness 88%–90% of the time (Gotoh, 2006). As the Micro Motionlogger was manually scored, double scoring by two trained members of the research team was undertaken on 33% of randomly selected sleep files to assess the reliability of manually selected sleep intervals as performed previously (Edgar et al, 2021). Any discrepancies of more than 15 min for either “start time” or “end time” of the sleep interval were flagged and re‐analysed.…”

“…With respect to physical performance, longer sleep durations have demonstrated improved training capacity (Cook et al, 2012) and improved aerobic adaptations in athletes (Teece et al, 2021). Similarly, when stratifying military trainees into two quantile groups based on sleep duration, small benefits in aerobic fitness were observed in those who averaged only a modest 36 min longer sleep duration than a short-sleeping cohort (Edgar et al, 2021).…”

Recent Progress in Long-Term Sleep Monitoring Technology

“…Scientists have proven that there is a negative correlation between the number of steps taken for exercise and the onset of sleep apnea. So, sleep monitoring should be part of a complete, daily health test to help most people improve their sleep [ 27 , 28 , 29 ]. Figure 2 a demonstrates the current use of polysomnography, which is not convenient in-home conditions.…”