Sleep Extension May Decrease Sedentary Activity

Sleep extension increases total sleep time without decreasing overall activity levels.  These data, collected as part of a broader experiment to test the impact of sleep extension and subsequent sleep deprivation on health and performance, were recently published in the journal Sleep Medicine. 

The study was conducted at the Walter Reed Army Institute of Research (WRAIR) Sleep Research Center in partnership with the Sleep and Performance Research Center at Washington State University.  

Twenty-eight volunteers maintained their normal sleep routine at home and then were allowed to acclimate to the Sleep Research Center.  Subsequently, volunteers extended their time in bed to 10 hours per night at the Sleep Research Center for 6 nights.  During the day, volunteers were released from the Sleep Research Center without instructions about how to conduct their daily activities.  Sleep and activity were measured by wrist actigraphs worn continuously during the normal sleep period and week of sleep extension.  

Sleep deprivation has been associated with a range of negative consequences on learning, perception, digestion and other normal processes of the body.  These impacts typically get worse as one becomes more sleep deprived.  

Studies originally performed at WRAIR have demonstrated that extra sleep prior to a period of sleep deprivation can protect against performance loss and increase the speed of recovery.  Yet, other data have suggested that prolonged sleep duration is related to negative health outcomes and increased mortality, perhaps due to being more sedentary than individuals who sleep less. 

"This study is a win-win for the worlds of sleep and public health research. We not only showed the protective and recuperative values of sleep extension before and certainly after conditions of sleep loss, but also demonstrate that sleep extension produces a natural drive to be more active during waking hours," said Capt. Allison Brager, an author on the study and chief of the Sleep Research Center.  Further data are needed to fully understand and confirm this relationship.  

Understanding the relationship between sleep and performance and mitigating performance decrements from sleep deprivation remains an active field of study at WRAIR and a high priority for the military as a full night's sleep is often not an option for Soldiers—especially those operating in combat environments. 


This study was funded by Department of Defense Military Operational Medicine Research Program (MOMRP) and was conducted at WRAIR.  

The opinions or assertions contained herein are the private views of the author, and are not to be construed as official, or as reflecting true views of the Department of the Army or the Department of Defense. The investigators have adhered to the policies for protection of human subjects as prescribed in AR 70– 25.