Napping boosts sleep and cognitive function in healthy older adults
With age come changes in the structure and quality of our sleep. After about age 60, we have less deep (slow-wave) sleep and more rapid sleep cycles, we awaken more often, and we sleep an average of two hours less at night than we did as young adults. It was once thought that older people didn't need as much sleep as younger ones, but experts now agree that's not the case. Regardless of age, we typically need seven-and-a-half to eight hours of sleep to function at our best. So if you're not getting enough sleep at night, what about daytime naps? Or does napping disrupt the sleep cycle, ultimately yielding less sleep and more daytime drowsiness?
These questions were addressed in a study by researchers at the Weill Cornell Medical College in White Plains, N.Y., and published in the Journal of the American Geriatrics Society (February 2011). The authors concluded that napping not only increases older individuals' total sleep time — without producing daytime drowsiness — but also provides measurable cognitive benefits.
The study. This small but well-designed study involved 22 healthy women and men ages 50 to 83 who agreed to be evaluated in a sleep laboratory. During a one- to two-week preliminary period, participants kept sleep logs at home and wore monitors to track their nighttime movements. They were then brought into the sleep laboratory for three nights and two days and given a thorough sleep evaluation (using polysomnography and other techniques) and a battery of cognitive tests. After this initial laboratory session, participants started a month-long daily napping routine at home: half took short (45-minute) naps, and half took longer (two-hour) naps. After the second and fourth weeks, all returned to the lab for repeat assessments.