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 .
Short Daytime Naps Briefly Attenuate Objectively Measured Sleepiness Under Chronic Sleep Restriction
Study Objectives Napping is a useful countermeasure to the negative effects of acute sleep loss on alertness . The efficacy of naps to recover from chronic sleep loss is less well understood . Methods Following 2 baseline nights ( 10 hours ' time-in-bed ) , participants were restricted to 7 nights of 5-hour sleep opportunity .  Ten adults participated in the No-Nap condition , and a further 9 were assigned to a Nap condition with a daily 45-minute nap opportunity at 1300 h. Sleepiness was assessed using the multiple sleep latency test and a visual analogue scale at 2-hour intervals . Both objective and subjective indexes of sleepiness were normalized within subject as a difference from those at baseline prior to sleep restriction . Mixed-effects models examined how the daytime nap opportunity altered sleepiness across the day and across the protocol . Results Short daytime naps  attenuated sleepiness due to chronic sleep restriction for up to 6 - 8 hours after the nap . Benefits of the nap did not extend late into evening . Subjective sleepiness demonstrated a similar short-lived benefit that emerged later in the day when objective sleepiness already returned to pre-nap levels . Neither measure showed a benefit of the nap the following morning after the subsequent restriction night . Conclusions These data indicate a short daytime nap may attenuate sleepiness in chronic sleep restriction , yet subjective and objective benefits emerge at different time scales . Because neither measure showed a benefit the next day , the current study underscores the need for careful consideration before naps are used as routine counter measures to chronic sleep loss
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 .