By Seyma Calisgan

Sleep is a vital function that helps your body and mind to replenish and allows you to wake up renewed and refreshed. There are many questions one might have about sleep, including:

• What is sleep and why is it important?
• How many hours should I sleep?
• How does sleep affect my life in general, including my academic life?
• What can I do to ensure good sleep?

Let’s look at the answers to these questions!

What is sleep and why is it important?

The science of sleep

Your sleep cycle is controlled by an internal “body clock,” which determines whether you are awake or ready for bed. The circadian rhythm is a 24-hour cycle that this clock follows. The hormone cortisol is released when the sun rises in the morning. It promotes energy and alertness. The sleep-wake homeostasis is also connected to adenosine, a brain-produced chemical molecule. As you become more tired throughout the day, your adenosine levels rise and your body breaks down this complex molecule while you are sleeping. Additionally, as natural light fades in the evening, your body produces melatonin, which is a drowsiness-inducing hormone.

The cycle of sleep

Your whole sleep consists of multiple rounds of the sleep cycle. A person has 4 to 6 sleep cycles in a typical night, and the first sleep cycle is usually the shortest, lasting 70-100 minutes, while subsequent cycles last 90-120 minutes. However, the amount of time spent in each sleep cycle differs from person to person, depending on a variety of factors, including age, alcohol consumption, and previous sleep patterns. The sleep cycle is divided into 4 stages. These include 3 different stages of non-REM (NREM) and 1 stage of rapid eye movement (REM) sleep¹.

NREM sleep patterns

Stage 1

Stage 1 is the ‘dozing off’ stage, which usually lasts 1 to 5 minutes. A person can swiftly progress to stage 2 if they are not disturbed. During the NREM stage 1, the body has not relaxed; however, both body and brain functions begin to decelerate with brief twitches.  

Stage 2

Stage 2 sleep can last anywhere from 10 to 25 minutes. Each NREM stage 2 can last longer and a person’s NREM stage 2 sleep accounts for almost half of their total sleep time. During this stage, the body cools down, muscles relax, and respiration and pulse rate slow down.

Stage 3

Stage 3 sleep is known as deep sleep and it is more difficult to wake someone up. As the body relaxes, pulse, muscle tone and breathing rate decrease. This stage is crucial for restorative sleep because it allows the body to recover and grow. It could also help the immune system and other vital biological functions. This stage usually lasts for 20-40 minutes and gets shorter during the night.

REM sleep patterns

You do not enter the REM sleep stage until you have been asleep for roughly 90 minutes in normal circumstances. REM stages become longer as the night progresses, especially in the second half of the night. While the first few minutes of REM sleep are brief, later stages can continue up to an hour. In adults, REM stages account for roughly 25% of total sleep time².

How many hours should I sleep? How does sleep affect my life in general, including my academic life?

Quality sleep and its effect on academic life

Most individuals require at least 7 hours of sleep each night to function well cognitively and behaviourally. Li et al. (2022) reported that 7 hours of sleep is the best duration for the middle-aged and the elderly. This research stated that both less sleep and oversleeping are linked to mental health problems and poor cognitive performance. However, there is less clarity about why oversleeping leads to problems. It is possible that those with poor quality sleep tend to sleep more because they feel tired³.

Furthermore, Maheshwari and Shaukat’s research (2019) on the poor sleep quality of medical school students found that it had a significant negative impact on their performance (i.e. their grade point average (GPA)). Thus, good quality sleep can enhance cognitive skills, including learning and memory retention⁴.

What can I do to ensure good sleep?

Tips for a good night’s sleep

You can experience sleeping problems when dealing with stressful life events. However, when short-term insomnia progresses into long-term (chronic) insomnia, complications arise – this is when you should seek assistance. But there are certain things you can do to improve your overall sleep quality. These include:

•           Limiting your use of electronic devices before bedtime and keeping them away from your bed during the night

•           Not going to bed before you’re sleepy

•           Endeavouring to go to bed at the same hour every day

•           Increasing the amount of time you spend exercising during the day

•           Drinking caffeine in moderation as it can linger in your system for up to 8 hours⁵.

Don’t forget that quality sleep provides us with a healthy, productive and quality life.

If you feel like you suffer from sleep problems and these affect your life, the University offers some helpful sources. Follow the link below:

https://www.studentsupport.manchester.ac.uk/taking-care/