Each year, World Sleep Day reminds us that sleep isn’t just about shutting our eyes, it’s a biological necessity that affects our health, productivity, and longevity.
Yet, with late-night scrolling, demanding work schedules, and endless to-do lists, quality sleep often takes a backseat.
Have you ever woken up feeling like you barely slept, despite getting a full eight hours or have you struggled to fall asleep at night even though you’re exhausted?
Dr Oliver Rawashdeh from UQ’s School of Biomedical Sciences explains it could be due to your circadian rhythm, your body’s built-in clock, being out of sync.
“Imagine your brain as a 24-hour command centre, fine-tuned to the natural cycle of light and dark,” Dr Rawashdeh said.
“At its core is the suprachiasmatic nucleus—a tiny but powerful region in the brain that synchronises everything from your sleep to your metabolism.
“However, modern habits such as late-night scrolling, irregular schedules and artificial lighting can throw off our internal timekeepers, leading to chronic sleep issues.”
How do you keep your rhythm aligned?
Morning Light = Wakefulness: Sunlight signals cortisol release, boosting alertness.
Evening Darkness = Sleepiness: The absence of light helps your body produce melatonin.
Artificial Light = Confusion: Screens at night trick your brain into thinking it's still daytime.
Why sleep disruption matters – it’s more than just feeling tired
Losing sleep isn’t just an inconvenience, it’s a direct hit to your health. Here’s what happens when you don’t get enough:
- Memory & Brain Health: Sleep cleans out toxins from the brain and strengthens memory. Chronic sleep deprivation has been linked to cognitive decline and neurodegenerative diseases like Parkinson’s disease and Alzheimer’s disease.
- Heart & Metabolism: Poor sleep disrupts hunger hormones which can lead to weight gain, insulin resistance, and an increased risk of heart disease.
- Immune System: Sleep is when your body fights infections and repairs damage so if you skimp out on catching Z’s, you’ll be more prone to getting sick.
- Mood & Mental Health: Sleep deprivation fuels stress, anxiety, and depression and can make everything feel a lot harder.
The magic behind sleep cycles
Sleep isn’t just "on" or "off". Every night, your body moves through different sleep cycles that each play a crucial role:
- Stage 1 (Light Sleep): A brief transition as you start to drift off. Brain waves slow down, and muscle activity decreases.
- Stage 2 (Deeper Light Sleep): Heart rate and breathing slow. Your body prepares for deep sleep.
- Stage 3 (Deep Sleep): The most restorative phase—essential for immune function, memory consolidation, and muscle recovery. Growth hormone is released, repairing tissues.
- Stage 4 (REM Sleep): Brain activity spikes, and dreaming kicks in. Crucial for creativity, learning, and emotional balance.
Dr Rawashdeh said it’s important to understand sleep cycles as they each play a crucial role.
“A full sleep cycle lasts about 90–110 minutes, and you need four to six cycles per night for optimal health,” Dr Rawashdeh said.
“Deep and REM sleep are the most crucial phases of sleep – without them, you’ll wake up groggy, unfocused, and more likely to reach for an extra coffee… or three.”
Optimising your sleep & resetting your circadian rhythm
The good news is that you can retrain your body to improve your sleep. Here’s how:
- Get Morning Sunlight: 10-15 minutes of natural light resets your internal clock.
- Stick to a Consistent Schedule: Yes, even on weekends!
- Limit Screens Before Bed: Blue light suppresses melatonin; dim lights an hour before bed.
- Watch What You Eat & Drink: Avoid caffeine after 2 PM and keep heavy meals away from bedtime.
- Make Your Room a Sleep Sanctuary: Cool, dark, and quiet. Your bed is for sleep, not Netflix.
Final thoughts: sleep isn’t a luxury—it’s a necessity
In a world that glorifies "hustling" and staying up late, it’s easy to de-prioritise sleep, but that’s a costly mistake. Your brain, body, and overall wellbeing depend on quality rest.
So next time you think, "Just one more episode," ask yourself: Is it worth sacrificing my health?
Prioritise your sleep and your future self will thank you.
