When revision can be bad for you

Written by: Karen Sullivan | Published:
Image: Adobe Stock

At exam time, the negative impact of over-studying cannot be over-estimated. Karen Sullivan offers some words of caution to revising students...

In my last article, we looked at the increasing pressure on students to revise over holidays and across weekends; to put in nine-hour days to achieve top grades and opportunities (Getting exam revision right, SecEd, May 2018).

We looked at the fallacies behind this type of approach as well as the fact that the majority of students do not revise effectively. However, what we didn’t mention are the implications on health, wellbeing and even success, and these are most certainly cause for concern.

As a starting point, sleep is affected by over-studying, particularly in the lead-up to exams. Research by the Sleep Council found that 83 per cent of teenagers admit that their sleep is affected by worry and stress or exams. More than a third of those polled confessed to revising for between eight and 10 hours-a-day, with 56 per cent admitting to cramming the night before.

So why does this matter? The study pointed out that sleep triggers changes in the brain that help to improve memory which, of course, means that sleepless nights can undermine performance.

The National Sleep Foundation (Adolescent Sleep Needs and Patterns, 2000) also found that lack of sleep impacts on moods (anger, sadness, fear and anxiety were common) and subjects have difficulty controlling emotions.

They refer to a 1999 study (Dahl), which shows that sleep loss may be associated with decreased ability to stay focused and sit still, and cause problems completing tasks (resembling behaviours common in ADHD).

Moreover, insufficient sleep is, according to Professor Mary Carskadon, in Sleep in Adolescents: The Perfect Storm (2011), associated with poor grades, behaviour problems, substance abuse, driving crashes, overweight and immune-system compromise.

Other research suggests that sleep deprivation affects decision-making skills, decreases self-confidence, inhibits creativity and logical thinking, and affects concentration. Perhaps most worryingly, good-quality sleep is necessary for growth hormones to be released, which increase and maintain strength, form red blood cells that carry oxygenated blood, and promote muscle and bone growth. Physical health and development can be seriously compromised by regular periods of inadequate sleep.

A study from the University of Exeter (Luis Gracia-Marco et al, 2012) showed that teenagers who spent more time engaged in desk-bound and sitting activities, are showing low levels of bone mass in key regions of the body. The strongest connection between desk-bound behaviour and low bone mineral content was found in girls’ hips, which could lead to catastrophic problems in later life.

Toronto researchers (Biswas et al, 2015) looked at 47 studies of sedentary behaviour and found that even with some exercise, long periods at a desk (or similar) leads to cardiovascular issues, cancer and type 2 diabetes. In fact, prolonged sitting (eight or more hours-a-day – the recommended period for revision by some schools) increases the risk of developing type 2 diabetes by 90 per cent.

On an emotional level, another study found that more than three hours of revision per night can cause academic stress, physical health problems and a lack of balance (Cheung & Leung-Ngai, 1992).

Research undertaken in Australia (Kouzma et al, 2001) also suggests that students doing more revision and homework report higher stress levels, and more mood disturbance (including internalising and externalising problems and fatigue).

The toll of over-studying cannot be over-estimated, and it is hard to imagine that the risks are worth the rewards, particularly in the long term. Producing a generation of emotionally and physically unhealthy children, with an increasing number of mental health disorders and, quite apart from anything else, suffering from debilitating stress, all for the sake of a school’s league-table ranking or a place at university, is tragic and, in the long term, potentially catastrophic.

Healthy living is about balance, and when schools proscribe the opposite, some very dangerous lessons are being learned. In 2017, Childline reported that the number of young people seeking help due to exam stress (and exam results stress) increased by more than a fifth over the previous two years. And there is an irony. In 2013, a study published in the Journal of Experimental Education (Galloway et al) noted that there is, in many cases, an inverse correlation between studying time and grades. It found that revision taking longer than two and a half hours or more to complete diminished the positive effects of studying and led to increased stress and declining health among students.

Many young people are currently sitting exams and already experiencing myriad symptoms that will have both short and long-term effects. There is no doubt that schools have tried to combat this by offering “training” in study skills. But this isn’t the answer, either. Intervention research (Ergene, 2003) suggests that this does not reduce anxiety and can even affect performance.

The solution? Give the students a break. Quite literally. A maximum of four hours revision per day, and lots of relaxation time in between, with early nights, time with friends, and a positive frame of mind can go much further than days spent crouched over a desk.

More importantly, perhaps, maybe it’s time that we addressed this “audit culture” of over-testing and focused our efforts on creating young people who find joy in learning. They will be the ones who go furthest and fastest, who genuinely retain what they learn. And they will be the happiest ones of all. SecEd

  • Karen Sullivan is a best-selling author, psychologist and childcare expert. Email kesullivan@aol.com. To read her previous articles for SecEd, go to

Further information

  • Adolescent Sleep Needs and Patterns, National Sleep Foundation, 2000: http://bit.ly/2rOqcCk
  • Impact of Homework Stress on Children’s Physical and Psychological Wellbeing, Cheung & Leung-Ngai, Journal of the Hong Kong Medical Association, 1992.
  • Exam stress overwhelming for thousands of children, NSPCC, May 2017: http://bit.ly/2k2fxQh


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