Why Waking Up Is So Hard: The Science Behind Sleep Inertia
Bashing the alarm clock until it submits is a morning ritual for some. For others, waking up is a mild annoyance. But unless you’re of the rare breed that receives perfect amounts of rest each night, getting out of bed is difficult. How come?
The reason is a phenomenon called sleep inertia. Each night we fall asleep in four phases. If the alarm clock rings out while we’re in phases three or four, the deepest parts of our sleep, the hormones that keep us sleeping soundly are still coursing through our bloodstream. Physically, we’re still asleep, even if the light that hits our eyes is telling us to rise and shine.
We can’t avoid sleep inertia entirely — even the perkiest of morning people still have to ease out of their slumber to some degree. But we can take concrete steps to minimize the chance we’ll wake up in one of the deep-sleep phases.
Before bedtime, this includes disengaging from electronic devices that emit a blue backlight. This light disrupts the suprachiasmatic nucleus, a part of the brain that releases the sleep-promoting hormone melatonin. More generally, sleep science is finding how much time people spend in their bed, what foods they eat, and how stressed they are all influence their quality of sleep.
A final word of advice: Don’t press the snooze button. You aren’t helping yourself by restarting the sleep cycle. Spend that nine extra minutes opening the blinds and preparing your brain for the day ahead.