A parent stopped me after a talk in a school last year and said her son was studying until one in the morning and his results were going backwards. She wanted to know what else he could do. The answer was less, and earlier. I run Study Skills Ireland and sleep is the single most undervalued piece of exam preparation in the country.
How much sleep does a Leaving Cert student actually need?
Most teenagers need somewhere between eight and ten hours a night, and the great majority of Irish sixth years are running on considerably less than that through the exam year. The gap matters because sleep is not downtime, it is when the day’s study is consolidated into memory that can be retrieved under pressure.
There is a second wrinkle that catches families out. Teenage body clocks genuinely shift later during adolescence, so a sixteen year old who cannot fall asleep at half ten is not being difficult. That is biology, and it collides badly with a school day that starts at nine.
So the realistic target is not lights out at ten. It is a consistent bedtime that allows eight hours before the alarm, held roughly steady across the week, including at weekends.
Why does studying late actually cost marks?
Because the material studied in a sleep deprived state is encoded poorly and recalled badly, so the extra hour at midnight often produces less than an hour at seven the following evening would have. Worse, the tiredness carries into the next day, which reduces what is learned in class as well.
That is the part families miss. A late night does not only cost that night. It taxes the following day, and if the pattern repeats through a term the cumulative loss is far larger than the handful of hours gained.
I put it to students this way. You can borrow time from sleep, but the interest rate is brutal and you always pay it back the next morning, usually in a subject you are sitting in period one.
My child says they study better late at night. Are they right?
Some genuinely do work better in the evening, and a student who is alert at nine o’clock should use that. What almost nobody does better is work at midnight on six hours of sleep, and that is usually what is actually happening. Late is fine. Late plus short sleep is not.
The honest test is what time they get up and how they feel in first class. A student who works until midnight and rises at seven is not a night owl, they are simply sleep deprived and calling it a preference.
There is also a hidden reason for the late finish. Many students study late because they started late, having spent the early evening drifting. Fix the start time and the finish time usually fixes itself.
What about the night before an exam?
Stop studying in good time, do something ordinary, and go to bed at the usual hour. Cramming the night before an exam typically adds very little and costs a great deal, because it raises anxiety at precisely the moment the student needs to be calm and rested for a three hour paper.
The exception people cite is the student who feels better having looked over something. That is fine, within limits. Twenty minutes of light review of material they already know, finishing well before bed, is reassurance rather than study.
What I would rule out entirely is learning something new the night before. It will not be retained, and discovering a gap at eleven o’clock the night before the paper does nothing except frighten a student who needs to sleep.
How do I get a teenager to go to bed without a row?
Move the target rather than the argument. Agree a time the study stops rather than a time the light goes out, and get the phone out of the bedroom. Most late nights in Irish houses are not study running over, they are a student who finished at ten and then lay in bed on a screen until one.
That distinction is worth checking before you have any conversation about it. Ask what time they actually stopped working. Parents are often arguing about study when the real issue is two hours of scrolling in the dark.
A wind down helps more than a rule. Twenty minutes between finishing work and getting into bed, doing something that is not a screen, gives the brain a chance to come down from the material. Students who go straight from a physics problem to bed tend to lie there doing physics.
What does the Irish evidence say about sleep and exam stress?
Research on Irish students has repeatedly found sleep to be one of the first things to suffer in the Leaving Certificate year. The Economic and Social Research Institute’s study of Leaving Certificate stress found large numbers of students losing sleep with worry, with around forty per cent of female students reporting it and more than half feeling constantly under strain.
The My World Survey work carried out with Irish adolescents by Jigsaw and University College Dublin similarly found that good sleep habits and physical activity were associated with better mental health outcomes among young people.
None of that is surprising to anyone who has lived with a sixth year. It is useful because it lets you have the conversation as a health matter rather than a discipline matter, which is a considerably easier conversation to have.
What should a school night actually look like?
Finish study at a fixed time, leave twenty minutes before bed with no screen, and aim for eight hours before the alarm, held roughly steady at weekends. A fixed finish time does more for study quality than any extra hour, because it gives the student a reason to work efficiently while they are at the desk.
The weekend part matters more than families expect. Sleeping until one on a Saturday feels like catching up and mostly resets the body clock later, so Sunday night becomes impossible and Monday is a write-off.
If your child is sleeping badly because of worry rather than habit, that is worth raising with your GP. A tired student can be helped with a routine. An anxious one needs something different.
Frequently Asked Questions
How much sleep does a Leaving Cert student need?
Around eight to ten hours a night. Sleep is when the day’s study is consolidated into memory that can be recalled under exam pressure, so lost sleep costs more than the extra study hour gains.
Is it better to study late or get up early?
Earlier is usually better, but the deciding factor is total sleep. A student working until midnight on six hours of sleep is not a night owl, they are sleep deprived, and the following school day suffers too.
Should my child study the night before an exam?
Stop in good time and go to bed at the usual hour. Light review of familiar material is fine as reassurance. Learning something new the night before will not be retained and raises anxiety.
How do I get my teenager to bed earlier?
Agree a time the study stops rather than a lights out time, and get the phone out of the bedroom. Most late nights are screen time after study rather than study running over.
Does catching up on sleep at the weekend work?
Only partly. Sleeping very late on Saturday resets the body clock later, which makes Sunday night harder and Monday worse. A roughly steady pattern across the week works better.
Working smarter rather than later
Study Skills Ireland runs study skills seminars for secondary school students and talks for parents in schools across Ireland. Enda O’Doherty teaches students how to get more out of a shorter, better organised evening, which is how most late nights get solved.
You can see what the student study skills seminar covers, read about the parents seminar, or get in touch about bringing a session to your school.
