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Become a better student · Module 2: Body and brain

Sleep is part of revision

The work you do in the day is locked in at night. Cutting sleep to revise more is a bad trade.

Written by the Brainhub Editorial Team Cites published research Updated 13 Oct 2026 5 min read

The course unlocks one lesson at a time. You can read this now, but it only counts once you’ve finished Stop re-reading.

Key takeaways

1. How much sleep teenagers need

The American Academy of Sleep Medicine recommends 8 to 10 hours a night for 13 to 18 year olds, and 9 to 12 hours for 6 to 12 year olds.[1]

2. Sleep and memory

During sleep, the brain replays and strengthens memories from the day and links them to what you already know. Research reviews show that sleep after learning improves how well that learning is remembered.[2]

That means the hour you lose to late-night revision can cost you some of what you revised earlier in the day.

Revise in the evening, sleep at night, test yourself in the morning.

3. Why teenagers stay up late

In adolescence the body clock shifts later, so teenagers naturally feel sleepy later at night, while school still starts early. Screens, caffeine and busy evenings make it worse.[3]

4. Protecting sleep in exam season

Steady wake time

Get up at roughly the same time every day, including weekends.

Wind down

Stop revising 30 to 60 minutes before bed. Put the phone outside the bedroom.

No all-nighters

A full night before an exam does more than an extra few hours of cramming.

For parents: Phones charging outside bedrooms is one of the simplest rules that helps.

Try it now

Test yourself on this page

Answer in your head first, then check.

  1. 1. How much sleep do 13 to 18 year olds need?

  2. 2. What does sleep do for learning?

  3. 3. Why do teenagers feel sleepy later at night?

Your next steps

  • Set a fixed wake-up time for the next week.
  • Charge your phone outside your bedroom tonight.
  • Move your last revision session earlier in the evening.

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Sources

  1. Paruthi, S. et al. (2016). Recommended amount of sleep for pediatric populations: a consensus statement of the American Academy of Sleep Medicine. Journal of Clinical Sleep Medicine, 12(6), 785–786. doi:10.5664/jcsm.5866
  2. Diekelmann, S. and Born, J. (2010). The memory function of sleep. Nature Reviews Neuroscience, 11(2), 114–126. doi:10.1038/nrn2762
  3. Carskadon, M. A. (2011). Sleep in adolescents: the perfect storm. Pediatric Clinics of North America, 58(3), 637–647. doi:10.1016/j.pcl.2011.03.003

This guide is general study advice. Every student is different. A teacher can help you work out what fits.