Between 7 to 9 hours a night is recommended for young adults aged between 18 to 25 years old. However it’s important to keep in mind that people can be very different: some function very well with 6 hours, whilst others need 10-11 hours. All of these durations are appropriate for this age group.
Our research suggests that it’s more important to have sleep of good quality than spending a longer time in bed. If you only sleep 6 or 7 hours a night, that’s fine if your sleep is of good quality. What’s good quality? This is entirely subjective: if you feel refreshed and do not feel sleepy during the day!
Get up and go to bed at the same time every day, including on the weekends. This is boring – and usually unwanted – advice but it works, because it capitalises on regular cycle of the body clock which determines when we naturally want to sleep and be awake.
Avoid electronic screens in the 2-3 hours before bed. Phones, laptops, and tablet computers emit light that fools the body clock into thinking it is daytime and delays the time at which you naturally feel sleepy. This advice is particularly important for people who are night owls, who tend to stay up late.
Sleep cycles are roughly 90 minutes long so if you need to get up early, set your alarm for multiples of 90 minutes (1.5 hours) from when you go to bed. If you go to bed at midnight, try setting your alarm for 6am, 7:30am, or 9am. Add in an extra 5-15 minutes to take into account the time it takes you to fall asleep.
If you’re not naturally a morning person, it could be because you’re more sensitive to light than average. Leave the curtains/blinds open to let sunlight in and give a strong prod to your body clock that is it time to wake up.
If your alarm has got you up but you are feeling groggy, go outdoors and get some sun immediately! Sunlight, even on a cloudy day, is much brighter than indoor lighting and this will send a strong signal to your body clock that it is time to be awake and alert. It will also help you feel sleepy and go to bed on time at night.
Daylight and darkness are cues from the environment that tell the body clock when to prepare to be awake and when to prepare to sleep. In fact, the body clock and circadian rhythms are part of every system in the body and they make sure that all the biological processes in the body are synchronised, like musicians in an orchestra. This is why we have such a terrible time with jetlag or working night shift, when the body clock and circadian rhythms are out of sync with the cycle of day and night.
In a modern society where we have 24-hour access to artificial lighting and access to food, circadian health is the idea that when we sleep, move, and eat is as important as the quality of our sleep, how much exercise we do, and what we eat.
Dr Bin runs an online unit of study called Health Challenges: Sleep & Circadian Rhythms. All students and staff are welcome to self-enrol in OLET1509 in Canvas. This is a 0-credit point unit of study that introduces how sleep and circadian rhythms work. Students can also take OLET1510, a 2-credit point unit which develops on the concepts introduced in OLET1509 and goes into more detail about jetlag, shift work, insomnia, and other sleep and circadian disorders.
If you're an international student, register for Dr Yu Sun Bin's Wellness Webinar about mastering sleep ahead of exams on Wednesday 11 November at 4pm.