Watching TV At Bedtime Contributes To Sleep Debt

By Margarita Nahapetyan

Watching television at bedtime may contribute to chronic sleep problems, says a new study by U.S. researchers.

For the study purposes, the investigators analyzed data from more than 20,000 individuals with the ages of 15 years or older. All the participants have completed the American Time Use Survey between the years 2003 and 2006. The experts studied and recorded the activities that the subjects were engaged in, two hours before and after bed time. The results revealed that TV viewing was by far and away the dominant activity before bedtime, accounting for nearly 50 per cent of pre-bed time. On average, Americans spent almost half of their last two waking hours of each day watching the tube.

According to the authors of the study, Dr. Mathias Basner, MD, MS, MSc, and Dr. David F. Dinges, PhD, of the University of Pennsylvania School of Medicine in Philadelphia, they were quite surprised to discover that watching TV appeared to be the most important period of time for the beginning of the sleep time, rather than hours following sunset or other more biological factors. Therefore, in fact, it looks like television may make people stay up late, while alarm clocks are used to wake them up early, potentially reducing sleep time to much less hours that are physiologically needed.

The experts say that sleeping less than seven or eight hours on a regular basis impairs people's alertness and is also linked to a higher chance of morbidity, mortality and being obese. In spite of this fact, up to 40 per cent of American population sleep for less than the recommended time per night. Dr. Dinges said that given the relationship of lack of sleep with the health-related risks, there is a big concern that many individuals in the United States are chronically under-sleeping due to lifestyle choices.

Regardless the technologies that give U.S. viewers the opportunity to record and watch any program at a later time or on hand-held devices, people just wait till the end of he show to turn off the TV and go to sleep, Dr. Basner said. Interestingly enough, he noted, that those individuals who live in the United States' Mountain and Central time zones, who generally can watch television shows an hour early, get more sleep, compared to their counterparts who live in Eastern Standard or Pacific Standard Time zones.

Dr. Basner added that according to the new findings, watching less TV before going to bed and postponing work start time in the morning should be considered among the major behavioral changes in order to achieve extra sleep time and reduce continuous sleep debt. While it may not be easy to change the timing of work, giving up some TV watching in the evening should be possible to get an adequate sleep, he concluded.

The findings of the study were presented at SLEEP 2009, the 23rd Annual Meeting of the Associated Professional Sleep Societies.