Reset Your Body Clock: How to Understand and Align Your Circadian Rhythm

Tracey Mudge
Apr 21
7 min read

Have you ever felt like your body is just... out of sync? Maybe you’re wide awake at midnight but groggy by midmorning. Or you crash hard in the afternoon, even after a full night’s sleep. These issues often have less to do with how much you’re sleeping and more to do with when your body thinks you should be asleep or awake.

That’s the power of your circadian rhythm - your internal body clock that runs 24/7 behind the scenes. When it’s in sync, you feel energized, alert, and clear-headed during the day, and ready to drift off naturally at night. But when it’s off? Everything can feel harder - sleep, mood, focus, and even digestion.

In this article, we’ll break down what circadian rhythms are, why they matter so much, what disrupts them in modern life, and—most importantly—how to reset yours using practical, evidence-backed strategies.

What Exactly Is Your Circadian Rhythm?

Your circadian rhythm is your body’s internal timekeeping system. It governs a wide range of biological processes - your sleep-wake cycle, hormone levels, body temperature, alertness, and even metabolism. It repeats roughly every 24 hours and is heavily influenced by external cues, especially light.

The control centre of this rhythm is a tiny part of your brain called the suprachiasmatic nucleus (SCN). This “master clock” takes in signals (most importantly, light exposure through your eyes) and helps coordinate the timing of other biological clocks throughout your body, down to the level of individual cells.

When your circadian rhythm is working properly, your body knows when to release melatonin (to help you sleep), when to boost cortisol (to help you wake), and when to carry out tasks like tissue repair, digestion, or hormone regulation.

In a perfect world, your internal clock would be perfectly synchronized with the rising and setting of the sun. But modern life? Well, it complicates things.

Why a Healthy Body Clock Is So Important

A well-functioning circadian rhythm isn’t just nice to have - it’s vital for your physical and mental health. When your internal clock is aligned with your lifestyle and your environment, your body operates like a well-oiled machine.

Here’s what happens when your rhythm is in sync:

You fall asleep easily and stay asleep through the night
You wake up naturally and feel refreshed in the morning
Your energy is stable, and your mind is sharper during the day
Your hormones, digestion, and metabolism work more efficiently
Your immune system is better regulated

But when your rhythm is out of sync (say, you’re sleeping at odd hours, exposed to light late at night, or constantly shifting your schedule) your body gets confused. And that confusion can lead to:

Sleep difficulties (trouble falling or staying asleep)
Daytime fatigue and foggy thinking
Low mood or increased anxiety
Disrupted digestion and increased sugar cravings
Increased risk of burnout, metabolic issues, and immune dysfunction

Over time, chronic circadian disruption can contribute to more serious health concerns, including obesity, type 2 diabetes, depression, cardiovascular problems, and increased inflammation.

What Commonly Disrupts Your Circadian Rhythm?

You might be surprised how easy it is to throw off your internal clock. These are some of the most common rhythm disruptors in our everyday lives:

Artificial Light at Night

Exposure to bright or blue-toned light in the evening suppresses melatonin and delays your natural sleep window. This is especially true for light emitted by screens - phones, tablets, TVs, and computers. Even bright overhead lighting can interfere.

Lack of Natural Light in the Day

Many people spend most of their day indoors under dim lighting or fluorescent bulbs. Without strong morning and daytime light exposure, your body doesn’t get a clear signal to “wake up,” which weakens the strength of your rhythm overall.

Inconsistent Sleep and Wake Times

Changing your schedule too often (going to bed late on weekends, sleeping in some days and waking early on others) creates what researchers call social jet lag. Your internal clock becomes misaligned with your social or work schedule, leading to grogginess, irritability, and poor-quality sleep.

Shift Work or Nighttime Activity

People who work night shifts, rotating shifts, or overnight hours often experience significant circadian disruption. The body isn’t built to be fully alert and functional during the night, and trying to sleep during daylight hours goes against our natural cues.

Jet Lag and Time Zone Travel

Flying across time zones throws your internal clock out of sync with local time. It often takes several days to fully adjust, especially when travelling eastward (which shortens the day and is harder to adapt to).

Caffeine, Meals, and Exercise at the Wrong Times

Having caffeine too late in the day, eating heavy meals close to bedtime, or exercising intensely late at night can all delay your body's wind-down process and interfere with your natural rhythm.

Signs Your Rhythm Might Be Off

Not sure if your circadian rhythm needs a reset? Here are some common clues:

You stay up late even when you’re tired
You feel groggy or disoriented in the morning
Your sleep pattern varies a lot between weekdays and weekends
You rely on caffeine to stay alert during the day
You struggle to fall asleep, even when you're exhausted
You often feel mentally foggy or emotionally flat
You have energy crashes in the afternoon or evening

If any of these sound familiar, your body clock might be out of alignment - and it’s worth bringing it back on track.

Resetting Your Rhythm: What Actually Works

Circadian rhythms are responsive to signals. By sending your body the right cues at the right time, you can support better sleep, sharper focus, and more balanced energy throughout the day.

Here’s what helps most:

Expose Yourself to Morning Light

Morning light is the strongest anchor for your circadian clock. It helps shut down melatonin production, boost cortisol levels, and signal that it’s time to be awake.

Try this:

Get outside within 30–60 minutes of waking—even for 10–15 minutes
Sit near a sunny window if outdoor light isn’t an option
Take your morning coffee or breakfast outdoors if you can
If mornings are dark (especially in winter), consider a light therapy lamp

The earlier and brighter the light, the stronger the signal to your internal clock.

Dim the Lights and Unplug at Night

Evening should be about winding down - not flooding your senses with stimulation.

To support melatonin and sleepiness:

Use warm-toned, dim lighting in the evening
Turn off bright overhead lights and switch to lamps
Avoid screens for at least an hour before bed
Try wearing blue-light-blocking glasses after sunset
Do calming activities instead—reading, journaling, or quiet music

Think of your evening like a plane descent: gradually reduce stimulation and light as bedtime approaches.

Keep a Steady Sleep-Wake Schedule

Consistency matters more than perfection. Try to wake up and go to bed at roughly the same time every day - even on weekends. This regularity helps anchor your rhythm, making it easier to fall asleep and wake naturally.

Pro tips:

Aim for 7–9 hours of sleep per night
Limit weekend “sleep-ins” to no more than an hour later than usual
Set a nightly wind-down reminder, not just a morning alarm
Track your pattern for a week to spot inconsistencies

Time Your Meals, Caffeine, and Movement

Your body loves routine—not just in sleep, but in eating and movement too.

To reinforce your rhythm:

Eat meals at similar times each day
Have breakfast within an hour of waking to help set your metabolic clock
Avoid large or heavy meals in the 2–3 hours before bed
Cut off caffeine by mid-afternoon (2–3 pm)
Exercise during the day (ideally in daylight) but avoid intense workouts too close to bedtime

Evening exercise isn’t bad, but aim to finish at least an hour before bed, and choose gentler movement like yoga or stretching if you’re sensitive to nighttime stimulation.

Create a Sleep-Friendly Environment

Make your bedroom a signal for sleep - not stress or stimulation.

Set the scene for circadian success:

Keep it dark: use blackout curtains or an eye mask
Keep it cool: around 16–19°C (60–67°F) is ideal
Keep it quiet: use earplugs or white noise if needed
Keep it clutter-free: your brain sleeps better in a calm space
Keep screens out: ditch the bedtime scrolling

Even small changes (like switching to warm lighting or removing a glowing alarm clock) can make a noticeable difference.

Small Changes = Big Results

The great thing about circadian health is that you don’t need to overhaul your entire lifestyle to see improvement. Just a few consistent, light- and timing-based changes can have a powerful ripple effect on how you sleep, wake, and function every day.

You don’t have to be perfect. You just have to be intentional. Start with one or two changes (like getting outside for light each morning or dimming the lights earlier at night) and build from there. Within a week or two, you’ll likely notice:

Easier time falling asleep
Less grogginess in the morning
More stable energy during the day
Fewer crashes and mood dips
A stronger sense of overall wellbeing

Your body clock wants to work with you. You just need to give it a little support.

Final Thoughts

Circadian rhythms are the unsung heroes of your health. They regulate far more than just sleep - they influence your brain, body, and emotional state in ways you probably don’t even notice until something feels off.

In a world filled with late nights, glowing screens, irregular schedules, and artificial lighting, your body is constantly being asked to adapt. But when you take steps to align with your natural rhythm (even just a little) you’ll likely feel the difference.

Better sleep, better mornings, better mood. It’s not about perfection - it’s about creating a rhythm that works for you.

References

Ministry of Health New Zealand. (n.d.). How much sleep do we need? Retrieved from https://www.health.govt.nz/your-health/healthy-living/food-activity-and-sleep/sleeping

Sleep/Wake Research Centre, Massey University. (n.d.). Publications and research reports. Retrieved from https://www.massey.ac.nz/research/research-centres/sleep-wake-research-centre/

Royal Society Te Apārangi. (2021). Blue Light Aotearoa: Evidence summary. Retrieved from https://www.royalsociety.org.nz/what-we-do/our-expert-advice/all-expert-advice-papers/blue-light-aotearoa/

University of Otago – Brain Health Research Centre. (n.d.). The body clock and mental health. Retrieved from https://www.otago.ac.nz/bhrc/

Centers for Disease Control and Prevention. (n.d.). Circadian rhythms: How your body’s clock affects your health. Retrieved from https://www.cdc.gov/niosh/emres/longhourstraining/light.html

National Institute of General Medical Sciences. (n.d.). Circadian rhythms fact sheet. Retrieved from https://www.nigms.nih.gov/education/fact-sheets/Pages/circadian-rhythms.aspx