Have you ever climbed into bed feeling completely exhausted, only for your brain to suddenly become very busy?
You remember the email you need to send tomorrow.
Then the appointment you need to book.
Then the shopping you forgot to do.
Then you start thinking about something that happened earlier in the day.
And before you know it, you’re lying there thinking:
I really need to get to sleep!
Which, ironically, doesn’t always help you get to sleep.
For many people, the transition from a busy day to bedtime is when all those unfinished thoughts finally have a chance to surface. And there may be a very simple reason why.
Your brain doesn’t necessarily switch off just because you get into bed
During the day, we’re constantly giving our brains things to focus on.
- Work.
- Family.
- Conversations.
- Exercise.
- Emails.
- Notifications.
- Decisions.
Then suddenly the lights go out, the house is quiet and there are no more distractions.
That’s often when the brain starts processing everything that hasn’t been dealt with yet.
Research into pre-sleep cognitive activity has found that thoughts involving worry, planning and problem-solving are particularly common around bedtime, and that greater cognitive arousal is associated with difficulty falling asleep.
A systematic review of the evidence found that people with insomnia tend to experience more thoughts that interfere with sleep, including worry, rumination and planning.
In other words, sometimes the problem isn’t that you’re not tired.
Your brain is simply still busy.
So what if you gave those thoughts somewhere to go?
This is where our Marginal Gain comes in.
Before bed, spend 5–10 minutes writing down what’s on your mind.
Write down:
- Anything you need to remember tomorrow
- Tasks you don’t want to forget
- Things you’re worrying about
- Anything you need to deal with the following day
Then close the notebook. You don’t need to solve everything right in that moment.
You’re simply getting those thoughts out of your head and onto paper so the detail is captured enough to let you switch off and let the unconscious part of your brain work on them for a while.
It might sound simple and common sense but it’s back by science.
The five-minute to-do list experiment
In a 2018 study published in the Journal of Experimental Psychology, researchers looked at whether writing before bed could influence how quickly people fell asleep.
Fifty-seven healthy young adults spent a night in a sleep laboratory. Before going to bed, they were asked to spend five minutes writing.
One group wrote about things they had already completed.
The other group wrote a specific list of things they needed to remember to do over the coming days.
The results were interesting.
The people who wrote the to-do list fell asleep significantly faster than those who wrote about completed activities.
And the more specifically they wrote down the tasks they needed to remember, the faster they subsequently fell asleep.
It wasn’t a huge intervention. There was no supplement. No complicated sleep protocol. No expensive sleep technology.
Just five minutes of writing.
Why might this work?
One possible explanation is cognitive offloading.
When something is important, unfinished or worrying, we have to keep some mental attention on it.
“Don’t forget to email Sarah.”
“I need to book that appointment.”
“Remember to pick up the dry cleaning.”
“What am I going to do about that problem tomorrow?”
Writing these things down creates an external record that allows you to close the mental loop.
Instead of repeatedly reminding yourself to remember something, you’ve given yourself somewhere to come back to it.
The 2018 study found that the specificity of the to-do list mattered too. More detailed lists were associated with faster sleep onset, suggesting that putting specific future tasks onto paper may be more useful than simply writing vague thoughts.
What About Worries?
This is where we need to be a little more careful.
Writing isn’t automatically a cure for worry or insomnia. Research on expressive writing in people with insomnia has produced mixed results.
One study found that a writing intervention reduced one measure of pre-sleep cognitive arousal but didn’t significantly reduce the time it took participants to fall asleep.
So we’re not suggesting that writing down your worries will magically switch off your brain.
The stronger evidence for this particular Marginal Gain is around writing down specific future tasks and things you need to remember.
And that makes sense. The goal isn’t to spend 20 minutes analysing everything that went wrong that day.
It’s to give your brain a simple message:
“I’ve written it down. I don’t need to keep remembering it tonight.”
Try the 5-minute brain dump
Tonight, about 5–10 minutes before bed, take a notebook and write down anything that’s occupying your mind.
Then put the notebook away.
Don’t keep working. Don’t start solving tomorrow’s problems at 11pm.
You’ve done enough. You’ve captured them. Now you can leave them until tomorrow.
The Marginal Gain
Better sleep doesn’t always require a dramatic change.
Sometimes it’s about removing one small obstacle that’s getting in the way.
For a busy mind, that obstacle might simply be the feeling that you have to keep remembering everything.
So give your brain somewhere to put it.
Five minutes. One notebook. Fewer things to hold onto.
Try it for the next three nights and notice what happens when you get into bed.
You might find that your mind has a little less to say.
References
Scullin MK et al. (2018)
Journal of Experimental Psychology: General, 147(1), 139–146.
Lemyre A et al. (2020)
Pre-sleep cognitive activity in adults: A systematic review.
Sleep Medicine Reviews, 50, 101253.
Hall M et al. (2009)
An experimental assessment of a Pennebaker writing intervention in primary insomnia.
The study examined whether expressive writing could reduce pre-sleep cognitive arousal and sleep-onset difficulty. Results were mixed, highlighting why the strongest claim here is around specific task-list writing rather than writing being a universal treatment for insomnia.
