THE WALKING TIRED

Think you’re getting enough sleep? You may be fooling yourself. (Experts say most of us are.) Here’s what you need to know to sleep better, and how using a sleep tracker can help—or hurt.

S By Christie Aschwanden leep—we know we need it, but too often it’s the first thing to go when we’re crunched for time. Our blasé attitude toward sleep has created a society of zombies walking around at half-power. And the worst part is that we might be too tired to even notice!

“Most of the time when someone says they only need five or six hours of sleep, that means their ability to tolerate sleep deprivation is better than most,” says Meeta Singh, M.D., medical director at the Henry Ford sleep laboratory in Detroit. “They’re actually walking around with sleep debt and have forgotten what it feels like to be awake and alert.”

For older people, there are other repercussions. A recent summary of sleep data gleaned from 10 million Fitbit users over nearly 6 billion nights corroborated previous research showing that the amount of deep sleep we get decreases with age. “You start slowly losing the robustness of ‘slow wave’ sleep,” the dreamless, non-REM sleep that is among the most restorative, says Sigrid Veasey, M.D., a professor of medicine at the University of Pennsylvania’s Perelman School of Medicine.

In other words: Do nothing to change your sleep habits over the years and it’s a slippery slope to zombieland. Luckily, with a boost from the self-tracking movement, science is uncovering more keys to help improve our sleep.