In June 2009, Drs. Basner and Dinges published an article titled “Dubious Bargain: Trading Sleep for Leno and Letterman.” Is this something you can relate to- staying up late to watch your favorite show even when you know you’re tired?
The relationship between exercise and sleep
The U.S. Census Bureau has a continuous telephone survey of 105 million households. It is called the American Time Use Survey (ATUS). This paper looked at how people spent the 2 hours before bed, and the 2 hours after getting up. They grouped people into 3 categories: Long workers (>8 hours daily), short workers (<8 hours) and non workers.
An estimated 20-40% of adults sleep less than the recommended 7+ hours each night. Remember that measured sleep is usually less than reported sleep, so these estimates may be low. Short sleep duration is associated with increased illness and obesity. The researchers’ goal was to determine if there are discretionary activities that can be eliminated to increase sleep time.
Among the three groups, bedtime was the same, and the long workers got up earlier than the others. People watch TV for 55 minutes of the 2 hours before bed. Travel and work took up 27% (about 30 minutes) of the 2 hours after waking for the day.
The authors conclude that watching TV may be an important social cue of approaching bedtime. They also conclude that “giving up some TV viewing in the evening should be possible to reduce chronic sleep debt and promote adequate sleep in those who need it.”