TempoLife › Nutrition & fitness glossary › Deep sleep
Deep sleep
The slow-wave stage (N3) where the body does most of its physical recovery.
Deep sleep is the slow-wave stage of the night, labelled N3 in a sleep lab. Brain waves slow right down, and it is the hardest stage to be woken from — pulled out of it, you feel groggy and disoriented for several minutes.
It is when most of the body's physical repair happens: tissue growth and mending, immune activity, and the clearing of by-products the brain builds up while awake. Most of your deep sleep is packed into the first half of the night, which is one reason a late bedtime costs you more than the clock suggests.
You cannot force deep sleep directly, but you can protect it: a consistent schedule, a cool dark room, and keeping alcohol and late caffeine away from bedtime all raise the share you get. Chasing a "deep sleep percentage" on a tracker is less useful than simply getting enough total sleep at regular hours.
Frequently asked questions
Deep sleep?
The slow-wave stage (N3) where the body does most of its physical recovery. Deep sleep is the slow-wave stage of the night, labelled N3 in a sleep lab. Brain waves slow right down, and it is the hardest stage to be woken from — pulled out of it, you feel groggy and disoriented for several minutes.
