Better Sleep Starts Here: Understanding Your Sleep Cycle

14.03.25

I have a love/hate relationship with sleep, and I am sure I am not the only one. Sleep is wonderful, if you can get into bed, fall asleep easily enough, sleep through the night, and wake up when you want to. On the flip side, struggling with sleep can bring on emotions such as frustration, anger, and fatigue, which are not ideal when trying to settle the mind and body.

Having a deeper understanding your sleep cycle and the benefits of getting enough sleep, can help us prioritise making changes to our sleep routine!

Why do we sleep?

Sleep is a fundamental biological process that we all need, but its exact purpose is still not fully understood. Research suggests that one reason we sleep is to minimise energy consumption during periods when activity is less beneficial, such as at night for humans. Additionally, sleep allows the brain and body to rest and recover by replenishing depleted resources, consolidating memory, facilitating muscle repair, and supporting tissue regrowth. It is also believed that sleep plays a crucial role in neural growth and organisation in the brain.

How much sleep do we need?

Determining the right amount of sleep can be challenging. Generally, as we age, our sleep needs decrease until they stabilise once reaching adulthood, and then slightly decrease in older adulthood. On average, adults are recommended to get between 7 to 9 hours of sleep per night and research, although here are some specific guidelines for recommended amounts of sleep per age group. However, individual needs may vary based on factors such as sleep quality, pregnancy, health conditions, gender (women need more sleep than men) or recovery from injury or surgery.

Now, don’t instantly stress if you aren’t getting the recommended amount of sleep. Sometimes, a more useful factor is considering how rested you feel after sleeping. Feeling well rested is indicative of good sleep quality, which is actually superior to sleep quantity.

Sleeping too much can also not be a great thing. Oversleeping can lead to feelings of drowsiness, brain fog, and fatigue. If you are finding you are oversleeping on a regular basis, this may suggest that there is something else going on. If this is the case, we recommend chatting with your GP about this or any other questions you may have around how much sleep you need. Your GP will be able to provided you with specific information on this in conjunction with your personal circumstances.

The Sleep Cycle

You may be aware that there are two main types of sleep: rapid eye movement (REM) sleep and non-rapid eye movement (NREM) sleep. NREM sleep consists of three stages—N1, N2, and N3—each with distinct brainwave activity, muscle tone, and eye movement patterns.

N1 Stage – A light sleep stage lasting between 1 to 5 minutes.
N2 Stage – A deeper stage than N1, during which heart rate and body temperature drop. This stage is important for memory consolidation.
N3 Stage – The deepest stage of non-REM sleep, during which the body focuses on repair, bone and muscle growth, and immune system strengthening. Waking up from this stage can leave you feeling groggy.
REM Sleep Stage – The stage where dreaming occurs. In the first sleep cycle of the night, REM sleep is short, but it lengthens with each cycle, lasting up to an hour by the final cycle of the night.

A typical sleep cycle follows this pattern: N1 → N2 → N3 → REM. The first cycle lasts between 70 to 100 minutes, with subsequent cycles ranging from 90 to 120 minutes. On average, we experience four to five sleep cycles per night. It is also a bit of a myth that you have to sleep through the entire night. It is quite common for people to wake a few times across the night, usually occurring in-between cycles.

How our body knows when to go to sleep

Our body regulates sleep through two mechanisms: the circadian rhythm and the sleep drive.

Our circadian rhythm is an internal clock that aligns our mental and physical processes with the 24-hour cycle of the external environment. It is highly responsive to light changes, regulating temperature, hormones, metabolism, cognitive function, immune responses, and, of course, our sleep/wake cycle.

The sleep drive refers to our body’s increasing need for deep sleep as we remain awake. Upon waking, our sleep drive is low, but as the day progresses, it builds until the need for sleep becomes overwhelming, prompting us to rest.

Sleep Issues

Several factors can disrupt our body’s sleep mechanisms, leading to sleep problems. These include medical or mental health conditions (e.g., depression or anxiety), travel, medications, shift work, substance use, trauma, or poor sleep habits. Sleep issues can manifest in various ways, such as difficulty falling asleep, poor sleep quality, or insufficient sleep duration. These may lead to the development of a sleep disorder.

Treatments for Sleep Disorders

There are many different types of sleep disorders. Due to this, booking an appointment with a GP is a good first step. A doctor can recommend treatments tailored to your unique sleep concerns. Common GP-administered treatments include lifestyle changes to promote healthy sleep habits, medication adjustments, light therapy, oral appliances, and breathing devices.

In addition to a GP, a psychologist can also help support you with sleep difficulties by doing a deep dive into exactly what factors are getting in the way of your sleep. This work can complement any treatments recommended by the GP, by identifying what thoughts, feelings, and behaviours are contributing to the broader problem.

CBT-i

There are a variety of different talk therapies that your psychologist may use depending on what the sleep difficulty is, for example managing nightmares or processing trauma (which may be impacting sleep). Cognitive Behavioural Therapy for Insomnia (CBT-i) is an effective treatment for managing insomnia, a common sleep disorder characterised by difficulty falling asleep, staying asleep, or getting quality rest. CBT-i incorporates a number of strategies, including:

Cognitive strategies; to challenge and change unhelpful thoughts about sleep
Psychoeducation; to provide information on sleep, insomnia, stress, and sleep hygiene.
Behavioural interventions; such as stimulus control which strengthens the association between bed and sleep by restricting unhelpful activities like watching TV in bed.
Sleep restriction therapy; which improves sleep efficiency by limiting time in bed to match actual sleep duration, preventing hours of fruitless tossing and turning.
Relaxation techniques; including progressive muscle relaxation and deep breathing exercises, help reduce pre-sleep anxiety.

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If you are experiencing difficulties with your sleep, you don’t need to wait until you see a health professional to start making changes. A lot of the healthy sleep habits are things that you can start working on at home. You can find a range of different healthy sleep habits here and here. We recommend trying changing one or two habits at time. If you have trouble getting to sleep you could always try a relaxation exercise – here is a great one!