Work time is the primary lifestyle factor with
the largest reciprocal relationship to a person's sleep time
-- the more hours a person works, the less sleep that he or
she gets, according to a study published in the September 1
issue of the journal Sleep.
The study, authored by Mathias Basner, MD, of the University of
Pennsylvania, focused on a total of 47,731 respondents to the
American Time Use Survey (ATUS) conducted in 2003, 2004 and 2005.
The telephone survey was 15-20 minutes in length, and asked people
how they spent their time between 4 a.m. the previous day and
4 a.m. the interview day, including where they were and whom they
were with.
According to the results, most waking activities were inversely
related to sleep time. The largest reciprocal relationship to
sleep on both weekdays and weekends was found for work time.
Respondents who slept four-and-a-half hours or less worked an
average of 93 minutes more on weekdays and 118 minutes more
on weekends than the average sleeper, while those who slept
11-and-a-half hours or more worked an average of 143 minutes
less on weekdays and 71 minutes less on weekends than the average
sleeper.
"These cross-sectional results in a nationally representative
sample suggest that compensated work time is the most potent
determinant of sleep time, in which case work time should be
considered an important factor when evaluating the relationship
between sleep time and morbidity and mortality," said Dr.
Basner.
Dr. Basner noted that travel time (which composed of work commute
time and all other travel time) on both weekdays and weekends
was an unexpected second-place factor reciprocally related to
sleep time. These data suggest avenues for further research,
such as how sleep time may be squeezed by work commutes that
are starting earlier in the morning (to work) and/or later in
the day (to home), or commutes that are getting longer due to
such factors as urban sprawl or traffic volume growing faster
than transport capacity, said Dr. Basner. The findings also
highlight how little is known about how non-commute travel,
such as to shops, to schools, to religious and social events,
or long distance travel might be reducing sleep time, added
Dr. Basner.
Short sleep was also moderately related to time spent for socializing,
relaxing and leisure on weekends. Short sleepers also spent
more time engaged in education, household activities and, for
very short sleepers, watching TV. Except for time spent watching
TV, which increased with longer sleep times, all waking activities
decreased with increasing sleep time.
The differences between weekday and weekend results were minor,
except for two activities. Short sleepers spent less time watching
TV than respondents with average sleep times on weekends in
all sleep categories, and long sleepers spent less time socializing,
relaxing and leisure activities than respondents with average
sleep times.
The extent to which sleep time was exchanged for waking activities
was also shown to depend on age and gender. Sleep time was minimal
while work time was maximal in the age group 45-54 years, and
sleep time increased both with lower and higher age.
The ATUS is a federally administered, continuous survey on
time use in the United States sponsored by the Bureau of Labor
Statistics and conducted by the U.S. Census Bureau. The goal
of the survey is to measure how people divide their time among
life's activities in a nationally representative sample.
Experts recommend that adults get seven-to-eight hours of sleep
each night for good health and optimum performance.
Those who suspect that they might be suffering from a sleep
disorder are encouraged to discuss their problem with their
primary care physician or a sleep specialist.
Article: "American Time Use Survey: Sleep Time and
Its Relationship to Waking Activities.
