Studying sleep recovery

To examine the effects of sleep deprivation, researchers enrolled 159 healthy young adults into a short-term, laboratory-based study. Participants were randomly assigned to a sleep-restriction group or a normal-sleep (control) group.

In the sleep-restricted group, participants began with two nights of ten hours of time in bed. This was followed by five nights of four hours of time in bed and one night of sleep recovery of zero, two, four, six, eight, or ten hours of time in bed. The control group had ten hours of time in bed for the entire study.

Several times per day throughout the study, participants performed 20 to 30 minute computer tests to measure alertness, brain function, and memory. As expected, measurements declined over time in the sleep-restricted group. The more nights of restricted sleep, the more poorly the participants performed on the tests. And the fewer hours of sleep people were given to recover from sleep deprivation, the more poorly they performed on the tests.

What was not expected is how subjects given “adequate” sleep recovery performed. Even after eight and ten hours of sleep, participants failed to perform normally on tests of alertness, brain function, and memory. The authors concluded that complete recovery from chronic sleep deprivation requires more than ten hours of sleep in one night or multiple nights of recovery sleep.

Making sleep a priority

On average, we get about one and a half fewer hours of sleep per night than we did a century ago. Use the following tips to make sleep a priority and get your ZZZ’s:

• Go dark. Even tiny amounts of light from a cell phone or alarm clock can suppress production of melatonin, the hormone our bodies make to bring on sleep. Also keep bedroom temperatures cool.
• Create a bedtime routine. Taking a warm shower or bath, sipping herbal tea, or doing light stretches are all soothing practices. Keep consistent wake and sleep times.
• Mellow out. Avoid coffee, cola, or caffeinated tea after 12 noon. If you read before bed, avoid topics that upset or annoy you, such as politics, war coverage, or disaster reporting, and don’t leave the pile of unfolded laundry in the bedroom, which creates a feeling of things left undone.
• Unplug. Cut back on computer and TV time before bed.
• Avoid alcohol and heavy meals in the evening. They prevent the deep sleep needed for good health.
• Try patterned breathing. Try breathing in through your nose for a count of four, out through your mouth for eight, and repeating several times.
• If you’re not sleeping well, talk to your doctor about insomnia. Even if you’re not interested in medication, you may be referred to a sleep specialist who can give you other ways to beat insomnia.

(Sleep 2010;33:1013–26)