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How did you sleep last night? Your response may depend on how long you were in bed, how much of that time was spent tossing and turning or whether you felt comfortable. But it may also depend on whether you exercised today, what your wearable device says, or when you’re asked.
This article is part of a special series investigating key questions about sleep. Read more here.
“Everyone has their own definition of sleep quality — and that’s the problem,” says the sleep researcher. Nicole Tang At the University of Warwick, UK.
Although sleep quality and what determines it is a mystery scientists are still figuring out, we do know that a good night’s rest involves a series of sleep cycles, the distinct succession of phases of brain activity we experience during sleep (see chart below). And for most of us, each stage of these cycles is necessary to wake up refreshed. The average person experiences four to five full cycles during one night and disrupting them can come with health consequences, both short and long term.
“Poor sleep quality is associated with many adverse physical health outcomes,” he says. Jean-Philippe Chaput At the University of Ottawa, Canada. Similar to what you might expect from not sleeping enough (see “Why chronotype is the key to knowing how much sleep you need”), and includes risks higher than Cardiovascular diseasesfor Strokefor High blood pressurefor Type 2 diabetes and Weight gain.
Although there is no definitive consensus on what determines sleep quality, researchers and doctors frequently analyze sleep using electroencephalogram (EEG), which tracks brain activity during sleep…
