Count Rihanna among the ranks of successful people, Barack Obama and Donald Trump among them, who thrive on very little sleep.
“I only sleep three or four hours a night,” the singer and style icon says in Vogue Paris’ December issue, adding that she spends the rest of the night binge-watching documentaries and shows.
While the average American sleeps seven or eight hours a night, about 1 percent of the population — so-called “short sleepers” — function on far less, says Dr. Matthew Ebben, a sleep expert at Weill Cornell Medicine and NewYork-Presbyterian.
“When you go into a shoe store, you don’t ask for the national average shoe size,” he says. “Some folks only need four hours of sleep, others need 12 hours.” Those who qualify as short sleepers feel fully functional after four hours of sleep, he says, and neither fall asleep during the day nor take naps to make up for it.
Recent studies show that many short sleepers share a genetic mutation that prevents them from sleeping for more than six hours a night. But those extra waking hours may not be as productive as one might think.
“[Short sleepers] might have a propensity toward manic behavior — you’re high-strung, we might say ‘wired,’” says Dr. Donald Greenblatt, director of the Sleep Center at the University of Rochester Medical Center, citing a 2001 study published in the Journal of Sleep Research.
‘When you go into a shoe store, you don’t ask for the national average shoe size. Some folks only need four hours of sleep, others need 12 hours.’
It’s a different story for those who do need seven or eight hours of sleep, but get far less. In that case, Greenblatt says, excessive sleepiness can impact concentration, memory, attention span and response time. “With 24 hours of sleep deprivation,” he says, “your response time will be as bad as it would be after [drinking] a six-pack of beer.”
So how much sleep do you really need? Ebben says the best way to find out is to log your sleep hours and monitor how you feel the next day. If you need an alarm clock to wake you up and sleep late on weekends, you probably aren’t getting enough shut-eye, which isn’t surprising for anyone juggling the stresses of what Rihanna calls “work work work work work work.”
In any case, Ebben says, “It’s good to know what your sleep need is even if your lifestyle doesn’t support that amount of sleep.”