THE DETAILS: Researchers from Belgium and Switzerland used magnetic resonance imagings (MRIs) to monitor brain activity of healthy young adult volunteers (16 extreme morning people and 15 night owls) who spent 2 nights in a sleep lab. After a night’s sleep, the volunteers were asked periodically to perform tasks that required sustained attention. All of the participants slept 7 hours a night, but the early risers woke up about 4 hours earlier in the day than the night owls.
The results showed that both groups performed similarly on the tasks for most of the day. But 10 hours after crawling out of bed, early birds showed lower levels of activity in parts of the brain relating to attention when compared with night owls. The early birds also felt sleepier and didn’t react as quickly during tasks. Researchers say early birds could be more sensitive to sleep pressure—the body’s need to get some sleep—than night owls.
WHAT IT MEANS: If you’re the type of person who likes to work out late at the gym or start a house cleaning campaign after the sun sets, you’re probably a night owl. And the good news? Sleeping in for a bit in the morning probably won’t make you less efficient during the day—and you even may be better than early risers at staying awake when you have to as the hour grows late. So follow your inner clock if you can. If you’re a night owl whose work schedule doesn’t match your preferred sleeping habits, though, be careful about spending extra hours in bed on weekend mornings. Sleep experts say that keeping the same wake-up time every day is an important strategy for avoiding insomnia.