Young adults can fall asleep, on average, in just 8.7 minutes while it takes older adults over 14 minutes.
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WASHINGTON: Healthy older adults need less sleep than their younger counterparts and, even with less sleep under their nightcaps, are less likely to feel tired during the day, scientists said.
The time spent actually sleeping out of eight hours in bed declined progressively and significantly with age, according to the study published in SLEEP, the journal of the American Academy of Sleep Medicine and the Sleep Research Society.
Older adults, aged 66 to 83 years, slept about 20 minutes less than middle-aged adults (40 to 55 years), who in turn slept 23 minutes less than young adults aged 20 to 30, the study said.
Unbroken sleep evades older adults
The older adults woke up significantly more often and spent more time awake after initial sleep onset than younger adults.
Deep, or slow-wave sleep, thought to be the most restorative phase of sleep, decreased with age, the study said.
But although older adults slept less deeply and less overall, and their sleep was less continuous than their younger counterparts', they also showed less need for a quick kip during the day.
The study was conducted at the Clinical Research Centre of the University of Surrey in England and involved 110 healthy adults without sleep disorders or complaints.
Youth fall asleep in less than 10 min
Forty-four of the participants were young, 35 middle-aged and 31 older adults. They slept normally one night, the baseline night, then had two nights where their sleep was interrupted, followed by one recovery night.
During the baseline night, younger adults spent an average of 433.5 minutes asleep compared to around 410 minutes for middle-aged adults and 390 for older adults.
On the same night, the younger adults had 118.4 minutes of deep sleep, compared to 85.3 minutes for middle-aged adults and 84.2 minutes for older adults.
But when asked to lie in a comfortable position on a bed during the day and try to fall asleep, young adults nodded off in an average of 8.7 minutes, compared with nearly 12 minutes for middle-aged adults and just over 14 minutes for older adults.
