The traditional picture of the aged uncle snoozing after lunch may have to be redrawn after researchers found twentysomethings are more likely to nod off. Daytime sleepiness is more common in younger people and older adults are more alert during the day and need less sleep at night, scientists from the University of Surrey say.
The findings reverse the conventional view that age brings an increasing propensity for napping. Despite spending a longer period asleep at night, young people aged 20 to 30 are more likely to find their eyes closing during the day than older people aged 65-plus.
Researchers studied 110 healthy adults at the University of Surrey who spent eight hours in bed. They found that the older they were the less time they spent sleeping. Adults over 65 slept for six-and-a-half hours on average, 20 minutes less than adults aged 40-55. They in turn slept 23 minutes less than those aged 20-30, who spent on average seven hours 13 minutes asleep.
Older people also woke more during the night and spent less time in deep, slow wave sleep, which is thought to be the most restful. Despite this they showed less propensity to fall asleep during the day than the young adults.