Spoon

Meditation and sleep

The 90-Minute Nap (One Full Sleep Cycle)

A nap long enough for one full sleep cycle, so you wake from lighter sleep instead of deep sleep.

Also called: Sleep cycle nap, Full-cycle nap, Long nap

Needs Apple Watch

A 90-minute nap is a nap long enough for one full sleep cycle: light sleep, deep sleep and REM sleep, after which sleep turns lighter again. Cycles average about 90 minutes but run from about 70 to 120[1]. Wake at the end of one and you skip the heavy fog of waking from deep sleep.

In Spoon, True Sleep counts your nap from the moment your Apple Watch senses you have fallen asleep, so 90 minutes means about 90 minutes of sleep.

Session
About 2 hours: falling asleep, 90 minutes of sleep, waking up
Nap lengths
Power nap 10 to 20 min, NASA nap 26 min, full cycle about 90 min
Good for
A short night behind you or a long evening ahead
Level
Beginner
Origin
Sleep research on nap length and sleep cycles
Needs
Apple Watch for True Sleep

How to do it

  1. Nap in the early afternoon, so you still sleep well tonight.
  2. Lie down somewhere dark and quiet, with your Apple Watch snug on your wrist.
  3. In True Sleep, pick a wind-down exercise and 90 minutes. With a plain alarm, add the time you usually take to fall asleep.
  4. Follow the wind-down breathing, then let yourself drift off. Don't watch the clock.
  5. When the alarm comes (in True Sleep, a strong tap on your wrist), stop it and sit up.
  6. Wait until you feel fully awake before you drive.

Benefits

  • Wake up from lighter sleep

    By about 90 minutes, you are usually past deep sleep, the hardest stage to wake from[1].

  • Deep sleep and REM in one nap

    Naps of 60 to 90 minutes with both improved learning on a visual task about as much as a night of sleep[5].

  • A fresher, more creative mind

    People whose nap reached REM did better on a creative word test than people who rested quietly or napped without REM[6].

  • Your nap starts when you fall asleep

    True Sleep counts from sleep, so a slow start never eats into your nap.

  • Calm before you drift off

    Slow breathing comes first, and you'll feel calmer and sleepier within a few minutes.

What the research says

In a lab study, 24 healthy young adults slept about 5 hours, then napped at 3 PM for exactly 5, 10, 20 or 30 minutes of sleep[3]. The 10-minute nap worked best overall: alertness and performance rose right away, and some gains lasted 155 minutes. Gains from the 20-minute nap appeared 35 minutes after waking. After 30 minutes of sleep, alertness and performance first dropped, then improved[3].

That dip is sleep inertia, the fog after waking. It is strongest in the first 30 minutes after waking and less likely after naps under 30 minutes[2]. Waking from deep sleep is the classic suspect, though a 2019 review found the evidence on its exact role mixed[2].

Longer naps reach REM. Naps of 60 to 90 minutes with deep sleep and REM produced about as much learning on a visual task as a night of sleep[5]. Naps with REM also improved creative problem solving more than quiet rest or naps without REM[6].

The NASA nap comes from a study of pilots on long-haul flights. Given a 40-minute rest opportunity in the cockpit, they slept about 26 minutes on average. Their performance was then 34 percent better and their alertness up to 54 percent better than in pilots who did not rest[4].

Why 90 minutes?

Deep sleep comes in the first part of a cycle. In the early cycles it often lasts 20 to 40 minutes, and it is the stage people are hardest to wake from[1]. So a nap of 30 to 60 minutes can end right in it and leave you foggy[2]. At about 90 minutes you are usually back in lighter sleep, with deep sleep and REM banked[1][5].

Cycles vary: the first often lasts 70 to 100 minutes, later ones 90 to 120[1]. If 90 leaves you groggy, try 80 or 100 next time.

Power nap, NASA nap or 90-minute nap?

  • 10 to 20 minutes (power nap): a quick lift with little grogginess. In one study, 10 minutes helped right away[3].
  • 26 minutes (NASA nap): the average sleep pilots got in NASA's cockpit study[4].
  • 30 to 60 minutes: more rest, but more risk of waking groggy from deep sleep[2].
  • About 90 minutes (full cycle): deep sleep and REM, then lighter sleep. Best after a short night or before a long evening[1][5].

When should a nap timer start?

A normal alarm counts from when you lie down. Falling asleep takes time, and it changes from day to day. Set 90 minutes, take 25 to drift off, and the alarm rings 65 minutes into your sleep, before even a short first cycle ends[1].

True Sleep starts the countdown when your Apple Watch senses, from your heart rate and movement, that you have fallen asleep. Set 90 and you sleep about 90, however long you took to drift off. It does not read sleep stages or track your cycles. It counts the minutes from the moment you fell asleep.

Tips

  • Lie down for True Sleep. Spoon Mode is the one you do sitting up.
  • Turn on the latest wake time whenever you must be up by a set time.

Safety

  • True Sleep is new in the beta. Keep a regular alarm for anything you cannot miss.
  • If your Watch never senses sleep, only the latest wake time will wake you. A dead battery means no alarm.
  • If you sleep poorly at night, skip long or late naps. They make it harder to fall asleep at bedtime.
  • Grogginess is strongest in the first 30 minutes after waking[2]. Wait until you feel fully awake before you drive.
  • True Sleep is a nap alarm. It is not medical care for insomnia or any sleep disorder.

True Sleep in Spoon

True Sleep is Spoon's nap alarm. It is new in the beta and needs an Apple Watch. Pick a wind-down exercise and a nap length, lie down and breathe. When your Watch senses from your heart rate and movement that you have fallen asleep, the countdown starts. Nothing buzzes then, so you stay asleep.

When time is up, a strong tap pattern repeats on your wrist for up to 2 minutes, or until you stop it. There is no snooze. The summary then shows when you fell asleep, how long that took and when the alarm went off.

  • Wind-down choices: 4-7-8 Sleep, Box Breathing, Coherent Breathing, Meditation or Custom.
  • Presets of 10, 15, 20, 26, 30, 45, 60 and 90 minutes, or 5 to 120 minutes in 5-minute steps.
  • Optional latest wake time (off by default): you wake by then, even if your Watch never senses sleep.
  • Start it from your iPhone or from your Watch.
Join the betaSee every exercise

Free public beta for iPhone and Apple Watch. This one needs an Apple Watch.

Questions

How long should a nap be?

For a quick boost, sleep 10 to 20 minutes: in a lab study, a 10-minute nap helped right away, and some benefits lasted more than two hours. For a full reset, sleep about 90 minutes, one full sleep cycle. Naps of 30 to 60 minutes more often end in deep sleep and leave you groggy.

Is a 90-minute nap too long?

Not if you have the time and slept too little. It covers about one full sleep cycle, so you get deep sleep and REM and usually wake from lighter sleep. Take it in the early afternoon so it doesn't cost you sleep tonight.

Why do I wake up groggy after a nap?

That fog is called sleep inertia. It is strongest in the first 30 minutes after waking, and more likely after naps longer than about 30 minutes, when you may wake from deep sleep. Keep naps to 10 to 20 minutes, or sleep a full 90.

What is the NASA nap?

It comes from a NASA study of pilots on long-haul flights. Given a 40-minute rest opportunity in the cockpit, pilots slept about 26 minutes on average. Afterward their performance was 34 percent better and their alertness up to 54 percent better than in pilots who did not rest.

Does True Sleep wake me at the end of a sleep cycle?

No. True Sleep does not read sleep stages or track your cycles. It counts the minutes you choose from the moment your Apple Watch senses you have fallen asleep. Set 90 and you get about 90 minutes of sleep, close to an average cycle.

When should you not nap?

Skip naps if you struggle to sleep at night, and avoid napping in the evening: a long or late nap makes it harder to fall asleep at bedtime. If you need a nap every day even after a full night's sleep, talk to a doctor.

Sources

  1. Suni E. Stages of Sleep: What Happens in a Normal Sleep Cycle? Sleep Foundation, 2025. sleepfoundation.org
  2. Hilditch CJ, McHill AW. Sleep inertia: current insights. Nature and Science of Sleep, 2019. pmc.ncbi.nlm.nih.gov
  3. Brooks A, Lack L. A brief afternoon nap following nocturnal sleep restriction: which nap duration is most recuperative? Sleep, 2006. pubmed.ncbi.nlm.nih.gov
  4. Rosekind MR et al. Alertness management: strategic naps in operational settings. Journal of Sleep Research, 1995 (summarized by the Sleep Foundation). sleepfoundation.org
  5. Mednick S, Nakayama K, Stickgold R. Sleep-dependent learning: a nap is as good as a night. Nature Neuroscience, 2003. pubmed.ncbi.nlm.nih.gov
  6. Cai DJ et al. REM, not incubation, improves creativity by priming associative networks. Proceedings of the National Academy of Sciences, 2009. pmc.ncbi.nlm.nih.gov

Updated October 2026. This page is for education, not medical advice. If you have a heart, lung or blood pressure condition, epilepsy, or you are pregnant, ask your doctor before you start a breathing practice with holds or fast breathing.