Conclusions : Chronic lack of sleep in adolescents is associated with greater risk of sports and musculoskeletal injuries .
Current evidence can not yet definitively determine the effect of acute lack of sleep on injury rates .
Background : Although sleep has been identified as an important modifiable risk factor for injury , the effect of decreased sleep on sports injuries in adolescents is poorly studied .
The objective of this study was to quantitatively and qualitatively review published literature to examine if a lack of sleep is associated with sports injuries in adolescents and to delineate the effects of chronic versus acute lack of sleep .
The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation.
OBJECTIVES To inform the debate over whether human sleep can be chronically reduced without consequences , we conducted a dose-response chronic sleep restriction experiment in which waking neurobehavioral and sleep physiological functions were monitored and compared to those for total sleep deprivation . DESIGN The chronic sleep restriction experiment involved r and omization to one of three sleep doses ( 4 h , 6 h , or 8 h time in bed per night ) , which were maintained for 14 consecutive days . The total sleep deprivation experiment involved 3 nights without sleep ( 0 h time in bed ) . Each study also involved 3 baseline ( pre-deprivation ) days and 3 recovery days . SETTING Both experiments were conducted under st and ardized laboratory conditions with continuous behavioral , physiological and medical monitoring . PARTICIPANTS A total of n = 48 healthy adults ( ages 21 - 38 ) participated in the experiments . INTERVENTIONS Noctumal sleep periods were restricted to 8 h , 6 h or 4 h per day for 14 days , or to 0 h for 3 days . All other sleep was prohibited . RESULTS Chronic restriction of sleep periods to 4 h or 6 h per night over 14 consecutive days result ed in significant cumulative , dose-dependent deficits in cognitive performance on all tasks . Subjective sleepiness ratings showed an acute response to sleep restriction but only small further increases on subsequent days , and did not significantly differentiate the 6 h and 4 h conditions . Polysomnographic variables and delta power in the non-REM sleep EEG-a putative marker of sleep homeostasis -- displayed an acute response to sleep restriction with negligible further changes across the 14 restricted nights . Comparison of chronic sleep restriction to total sleep deprivation showed that the latter result ed in disproportionately large waking neurobehavioral and sleep delta power responses relative to how much sleep was lost . A statistical model revealed that , regardless of the mode of sleep deprivation , lapses in behavioral alertness were near-linearly related to the cumulative duration of wakefulness in excess of 15.84 h ( s.e . 0.73 h ) . CONCLUSIONS Since chronic restriction of sleep to 6 h or less per night produced cognitive performance deficits equivalent to up to 2 nights of total sleep deprivation , it appears that even relatively moderate sleep restriction can seriously impair waking neurobehavioral functions in healthy adults . Sleepiness ratings suggest that subjects were largely unaware of these increasing cognitive deficits , which may explain why the impact of chronic sleep restriction on waking cognitive functions is often assumed to be benign . Physiological sleep responses to chronic restriction did not mirror waking neurobehavioral responses , but cumulative wakefulness in excess of a 15.84 h predicted performance lapses across all four experimental conditions . This suggests that sleep debt is perhaps best understood as result ing in additional wakefulness that has a neurobiological " cost " which accumulates over time
Conclusions : Chronic lack of sleep in adolescents is associated with greater risk of sports and musculoskeletal injuries .
Current evidence can not yet definitively determine the effect of acute lack of sleep on injury rates .
Background : Although sleep has been identified as an important modifiable risk factor for injury , the effect of decreased sleep on sports injuries in adolescents is poorly studied .
The objective of this study was to quantitatively and qualitatively review published literature to examine if a lack of sleep is associated with sports injuries in adolescents and to delineate the effects of chronic versus acute lack of sleep .