Published sleep research · Read this before you borrow another hour tonight
No new evening routine. No tracker. A free five minute check that shows which signals in your own answers speak loudest.
"I'll just catch up at the weekend."
Say that sentence out loud.
You know your own version. To bed at one because the day only stopped then. Lying awake for an hour while the day repeats itself. Waking at three and not getting away again. Waking at the alarm with the feeling that nothing happened in between. Needing twenty minutes and something warm before you are capable of anything. Falling over at three in the afternoon. Reading the same paragraph twice at your desk.
I am Jesse van der Velde. Not a guru and not a doctor. I study and share what published research says about how a body ages. I have been testing that on myself and with the people I guide for more than fourteen years.
The thought I hear a lot of people say is "it only costs me a tired morning".
Because researchers have measured what it costs, and that tired morning is the smallest item on the bill.
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Sleep looks like the one part of the day in which nothing happens.
Nothing gets made. Nobody gets helped. No work gets finished. So when the day runs short, that is where everyone takes it from.
That deal hangs on one assumption: the only price is that you are tired, and being tired is something you can push through.
That assumption is old, and it is the first piece the research has taken apart.
In 2013 Björn Rasch and Jan Born published an extensive review article in Physiological Reviews.¹
What was studied: what role sleep plays in memory, across more than a century of research in animals and humans.
How: this is a review article and not a new measurement. The authors first set out the history of the concepts and then work through the more recent findings.
The findings: the older idea was passive, namely that sleep protects fresh memories by keeping disturbing input away. Current theories describe something active. During sleep, memories go through a process of system consolidation. That starts with reactivating the neuronal representations of what was learned shortly before, which happens during deep sleep and reshapes those representations so they fit into long-term memory. The REM sleep that follows stabilises what has been reshaped, possibly. The authors describe sleep as a brain state optimised for laying down memory, as against the waking brain, which is optimised for taking in new material.
Read that again. Learning and storing are two different tasks, in two different states, and only one of them happens while you are awake.
That is what makes those missed hours expensive in a way a tired morning does not show.
Now the second thing that was measured, within a week.
In 1999 Karine Spiegel, Rachel Leproult and Eve Van Cauter published in The Lancet.²
What was studied: what a short term sleep debt does to metabolism and to hormones.
How: 11 young men were given only 4 hours in bed for six nights. The researchers looked at carbohydrate metabolism, thyroid stimulating hormone, the activity of the stress axis and the balance of the autonomic nervous system. They then compared those measurements with measurements in the same men at the end of a recovery period of six nights with 12 hours in bed.
The findings: glucose tolerance was lower in the sleep debt condition than in the rested condition (p less than 0.02). Thyrotropin levels were lower (p less than 0.01). Cortisol in the evening was higher (p is 0.0001), and activity of the sympathetic nervous system was increased (p less than 0.02).
And then the sentence the authors themselves wrote in their interpretation, and it is worth taking with you: the effects they saw resemble what is seen in normal ageing.
Eleven men, so a small study, all young and male, and six nights. Read it as a demonstration that a week is enough to move these measures, and not as a statement about you.
Does this sound familiar? Take the free check now.
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Six nights. That is how long that sleep debt condition lasted before glucose tolerance, thyrotropin, evening cortisol and sympathetic activity had all shifted.² Not six months. Six nights, in healthy young men.
4.50 and 4.24. In 2015, Aric Prather, Denise Janicki-Deverts, Martica Hall and Sheldon Cohen published in Sleep. 164 healthy men and women aged 18 to 55 wore a movement monitor on the wrist for seven days in a row and kept a sleep diary. They then went into quarantine, were given nose drops containing a rhinovirus, and were followed for 5 days to see who came down with a cold, defined as infection plus objective signs of illness.
Compared with people who slept more than 7 hours a night, people who slept less than 5 hours were 4.50 times as likely to catch a cold (95 per cent confidence interval 1.08 to 18.69), and people who slept 5 to 6 hours 4.24 times as likely (1.08 to 16.71). That association held regardless of the antibodies beforehand, of demographic characteristics, of the season, of body mass index, of psychological variables and of lifestyle habits.³
And then the honest detail people leave out. The group who slept 6.01 to 7 hours was not at higher risk (1.66, with an interval from 0.40 to 6.95 that runs straight through 1). How fragmented the sleep was showed no link with who came down with a cold. Look too at how wide those intervals are: this is a real finding with a lot of uncertainty about its size.
19 minutes, 26 minutes, 9.91 per cent. In 2015, James Trauer, Mary Qian, Joseph Doyle, Shantha Rajaratnam and David Cunnington published a systematic review with meta-analysis in Annals of Internal Medicine, covering 20 randomised studies with 1,162 participants, 64 per cent women, average age 56. Right after the programme, the time to fall asleep was 19.03 minutes shorter, the time awake after falling asleep 26.00 minutes shorter, and sleep efficiency 9.91 per cent better. Total sleep time went up by 7.61 minutes, and that is the only outcome without a firm conclusion, because the interval runs from minus 0.51 to 15.74. No adverse outcomes were reported.⁴
You know your own version of this. Mine is a run of years in which the working day did not stop until around midnight, and I went to bed at one because that was the only hour that was mine.
I told myself the price was a slow morning, and some coffee.
Look at what was actually running. Six nights is enough to move glucose tolerance, evening cortisol and the balance of the nervous system in healthy young men.² You feel none of it.
A judgement about your character gets you nowhere. Nothing constructive comes out of it. You cannot try harder to be a different person.
A week you have never measured does have a next step. You can put it next to the published research.
1. Taking that hour out of the night.
Whether you do that is of course up to you, and some weeks genuinely leave you no other room.
But be clear about what it does and does not do. It gets you an hour tonight. It takes that hour away from the state in which what you learned today is laid down, because that reshaping happens during sleep and not while you are awake.¹
2. "It only costs me the next morning."
That is the assumption the whole deal turns on, and it is the one most of the measurement work argues against. Six nights moved four separate hormone and metabolic measures in healthy young men.² A week of short nights before a virus exposure was linked to a few times as much chance of coming down with a cold.³
That tired morning is the only item on the bill you really feel.
3. Catching up at the weekend.
What it does: give back part of your sleep, and that is real. What it does not do: tell you which part of your sleep is the problem. If it sits in the falling asleep, in the waking up, or in getting up unrested, then a long Saturday does not touch the cause, and Monday starts the same week over again.
4. "That is just how I am built."
Set against it here is the number that carries the strongest evidence in this whole field.
The 2015 meta-analysis looked at a structured programme with no pill in it, built from at least three of the following parts: cognitive therapy, stimulus control, sleep restriction, sleep hygiene and relaxation. Across 20 randomised studies against groups without an active programme, people fell asleep about 19 minutes faster, lay awake about 26 minutes less during the night, and their sleep efficiency went up by about 10 per cent, with those changes appearing to hold at later measurement points.⁴
Note what that review cannot say, because the authors write it down themselves: people whose sleep problems came together with medical, psychiatric or other sleep disorders did not take part, so it does not describe everyone, and over the longer term the estimates are less sharp.
Four moves, one shared problem: none of them starts with what is actually going on with you.
The advice failed here, and it was the sensible sounding kind. You did nothing wrong. It can be different.
This is the heart of it. What has the strongest study evidence in this field is nothing you swallow. It is a structured programme made up of specific parts, and each of those parts is aimed at a specific part of the problem.
That means the first question is not what you should do.
The question is: which part of my sleep is the problem?
Falling asleep is one part. Staying asleep is a second. Waking up unrested is a third. How satisfied you are with your sleep as a whole is a fourth, and what it costs your day is the fifth. These are not the same complaint, and they do not point to the same part.
That is why the free BioProfile sleep scan asks exactly those five, and nothing else. Five minutes, and you know which of them speaks loudest in your own week.
On one condition, and that is the honest limit. This is a questionnaire. It collects your complaint. It does not measure a night, it is never a clinical category, and it will never tell you that you have something. What it gives you is your own five answers, read alongside what published research describes, and something specific to take to your doctor or your coach instead of "I sleep badly".
BioProfile has built that first step. A scientifically validated questionnaire, five minutes, free and with no account.
You answer questions about your nights and about your days. Then you see which signals in your profile speak loudest, and what the research says about them.
Not a medical examination. An analysis of your own answers. You use the outcome yourself, or you put it on the table with your doctor or your coach.
There is nothing to buy at the end. Not on this subject. I have nothing to sell you here. What there is instead is a specific answer rather than a general complaint.
You do the free check. Five minutes, no account, and there is nothing to buy.
Even if you do nothing with it, you have traded "it only costs me a tired morning" for an analysis of your own answers. That trade is worth five minutes.
And the next time it is one in the morning and the laptop is still open, you will know what you are making a decision about.
Do it now, while this page is still open. Tonight is coming either way.
Our scientifically validated questionnaire gives you answers
The scan is not a medical examination. It is an analysis of your own answers. If complaints persist, consult your doctor.
