The Importance of Sleep

Dear all

Exam season is officially upon us. It’s a time when everyone will be trying to do their best in their academic work. As we all know, when we have busy periods of time, the first thing many of us sacrifice is sleep. However, recent research from the University of Cambridge suggests that prioritising sleep might actually be the most effective ‘revision’ young people can do.

The 15-Minute Difference

A major study involving thousands of adolescents found that those who sleep longer and go to bed earlier tend to have improved brain function and perform better in cognitive tests. Interestingly, the researchers found that even small differences in sleep duration—as little as 15 minutes—can influence how well a person performs tasks involving focus, reading, and problem-solving.

The study divided teenagers into groups based on their habits. Those who went to bed earliest and slept the longest (averaging around 7 hours and 25 minutes) showed the best cognitive performance. In contrast, those who slept the least and went to bed the latest performed the poorest on tests. While 7.5 hours was the average for the top performers in this study, experts at the American Academy of Sleep Medicine and Johns Hopkins University suggest that teenagers need between nine and ten hours to function at their peak.

Why our Brain Needs Rest

Sleep is not just ‘downtime’ for our body, but is an active period of maintenance. While we sleep, our brain performs a ‘deep clean,’ clearing out toxins that build up during the day. Crucially for students, sleep is when memory consolidation happens. This is where our brain strengthens the connections formed while studying, turning what has been revised into long-term knowledge. Without enough sleep, our brain struggles to ‘prune’ unnecessary information and store the important facts you need for exams.

The ‘Delayed Sleep Phase’ Struggle

It isn’t always easy to get an early night. During adolescence, our biological clock—or circadian rhythm—naturally shifts. This ‘delayed sleep phase’ makes young people feel naturally more awake at night and sleepier in the morning. However, external factors can make this worse. Using screens (phones or tablets) before bed is particularly disruptive. The blue light from screens blocks the release of melatonin, the hormone that tells us it’s time to sleep, while clicks and likes on social media trigger dopamine, a chemical that keeps our brain alert and awake.

Top Tips for Exam Success

On Monday, I shared the following top tips with our students:

• The Golden Hour: Put away all electronics at least one hour before bed to allow your melatonin levels to rise.
• Consistency is Key: Try to wake up and go to sleep at the same time every day, even on weekends, to stabilise your body clock.
• Minimise Caffeine: Caffeine can stay in your system for hours; even a morning coffee can sometimes disrupt your ability to fall asleep at night.

Have a great weekend.

Best wishes

Michael Bond