If you think staying in bed on the weekends will make up for a
weeks’ worth of sleep deprivation, think again. A new study finds
that going long periods without sleep can lead to a sort of “sleep
debt” that cannot simply be undone with a little extra snoozing
from time to time.
The study involved a small number of participants, however, so
further research would be needed to verify the results.
Such chronic sleep loss may eventually interfere with your
performance on tasks that require focus, becoming particularly
noticeable at nighttime when the body’s natural sleep-wake cycle
isn’t giving you an extra boost.
Anyone who’s ever pulled an all-nighter knows how debilitating
sleep loss can be in the short term. Indeed, studies show that
after 24 hours without sleep, a person’s performance can drop to
the level of someone who is legally drunk.
But what about if those all-nighters turned into all-weekers? The
authors of the current study turned their attention to long-term
sleep loss, and examined whether the effects of such constant sleep
deprivation could be erased with an extended resting period.
The researchers put nine young adults on a sleep schedule that a
doctor or medical resident might experience on an on-call shift —
about 33 hours spent awake followed by 10 hours sleeping, a cycle
that is equivalent to about 5.6 hours of sleep every 24 hours. The
participants continued on this grueling schedule for three weeks,
at which time they were considered chronically sleep deprived. The
study also had a control group of eight young adults who were not
sleep deprived.
The subjects needed to periodically complete a performance task
designed to test their ability to pay attention and their reaction
time.
The sleep-deprived subjects generally performed the same as those
who had sufficient sleep if the test was given early on in the
“day,” just two hours after the subjects had awakened from their
long rest. This finding held true across all three weeks of the
study, suggesting that a long period of shut-eye could temporarily
make up for the chronic sleep loss.
However, the subjects performed significantly worse on tests that
were given later in the “day,” after 30 hours spent awake, as the
study progressed in weeks. For instance, the subjects fared poorly
on the last test of the day they took during week three as compared
with that same test during week 1. While they had a median reaction
time of 667 milliseconds in testing during week 1, which increased
to 2,013 milliseconds by week 3. The subjects appeared to have
developed a sleep debt — all that lost sleep really was catching up
with them.
Here’s how the results might play out in the real world: An
individual who is constantly sleep deprived during weekdays might
try to catch up during weekends. While that individual might feel
recovered after their sleeping spell, the study suggests the next
time they try to go without shut-eye, their performance may start
to deteriorate.
The findings also suggest that short-term and long-term sleep loss
may actually act on the brain in two different ways.
The sleep debt was also found to be most noticeable during the
subject’s nighttime. This could be due to the effects of our
natural sleep-wake cycle, or circadian rhythm, the researchers
suggest.
This cycle goes hand-in-hand with the periods of light/dark we
experiences as the sun rises and sets. Our natural tendency to want
to be awake during the day may mask signs of sleep debt when it’s
light out. But this protective effect may go away as darkness
arrives, the researchers say.
The findings are particularly applicable to people who work
odd-hour jobs that may have them going without sleep for extended
periods, such as health workers, truckers and emergency responders.
Chronic sleep loss could leave these individuals “vulnerable to
accidents and errors,” the researchers say. They advise public
health campaigns to emphasize the “potentially covert consequences
of chronic sleep loss.”
The study was conducted by Daniel Cohen, of Brigham and Women’s
Hospital in Boston, Mass., and colleagues. The findings were
published in the Jan. 13 issue of the Journal of Science
Translational Medicine.
So if you aren’t getting enough sleep, it’s important to understand
the consequences. Try to get a normal night’s sleep as often a
you can so that your body doesn’t slowly break down.
Have a great day and I’ll talk to you soon!
Sincerely,
Dr. Justin Trosclair
Resource: LiveScience, January 13, 2010
