How to Fix Your Circadian Rhythm: Resetting Your Internal Clock

Your circadian rhythm, also known as your sleep-wake cycle, is part of your internal clock that influences when you naturally fall asleep and wake up. This internal clock, known as the circadian clock, plays a crucial role in regulating sleep and waking by responding to external cues such as light exposure. It aligns roughly with the length of a day and doesn’t just regulate sleep—it also affects when you get hungry and when you feel most active.

A variety of factors influence your circadian rhythm, including:

• Light and Dark Cycles: Exposure to light and darkness helps regulate your sleep-wake cycle. Natural light during the day and darkness at night are crucial signals.
• Diet: What and when you eat can impact your circadian rhythm.
• Stress: High-stress levels can disrupt your sleep patterns.
• Exercise: Regular physical activity can help regulate your sleep-wake cycle.
• Social Environment: Your daily routines and social interactions also play a role.
• Temperature: Your body temperature fluctuates throughout the day, influencing your sleep cycle.

The circadian rhythm is controlled by a small bundle of brain cells called the suprachiasmatic nucleus (SCN).

When the SCN receives signals indicating it’s time to sleep, such as low light levels, it prompts your body to produce melatonin, which makes you tired. As light increases, your melatonin levels drop in the morning, signalling that it’s time to wake up and get moving.

How to Reset Your Sleep Schedule

If you struggle with falling asleep at night and experience short, unsatisfying sleep, it might be time to adjust your bedtime and daytime routines. Circadian rhythm disorders, such as advanced sleep phase disorder (ASPD) and delayed sleep phase syndrome (DSPS), can significantly impact your sleep patterns, leading to chronic sleep deprivation, poor performance, and even depression. Here’s how you can reset your internal clock:

1. Adjust Your Sleep Schedule

Your body adapts better to small changes over a more extended period rather than sudden, drastic ones. Instead of quitting your late-night habits cold turkey, try this gradual adjustment strategy:

• Set Your Goal: Decide on your desired sleep and wake times. For example:
• Goal: Sleeping at 10:30 PM and waking up at 6:30 AM.
  
• Shift Gradually: Move your sleep schedule by 15-minute intervals each night until you reach your goal. For example:
• Current Schedule: If you sleep at 12:00 AM and wake up at 8:00 AM, aim to adjust by 15 minutes earlier each night.
• First Night: Sleep at 11:45 PM and wake up at 7:45 AM.
• Second Night: Sleep at 11:30 PM and wake up at 7:30 AM.
• Continue this pattern until you reach your 10:30 PM to 6:30 AM goal.
• If you experience a setback, don't worry. Start again from where you are.

2. Maximize Light Exposure During the Day

Bright light significantly influences your circadian rhythm because your SCN is directly connected to your retinas. The more light your eyes absorb, the more awake you'll feel. If you find yourself struggling to stay awake during the day, try brightening up your environment:

• Open the Blinds: Let in natural sunlight in the morning.
• Example: Sleep with open curtains or open your blinds when you wake up to let in the morning sun.
  
• Sit Outside: Spend time outside during meals or breaks.
• Example: If you work in an office, try to have lunch outside. If you work from home, take your meals on your balcony or patio.
  
• Take Outdoor Walks: Go for daily walks to get more sunlight.
• Example: Use your breaks to take even a 10-15 minute walk. Sitting in a park for 15 minutes can also be an alternative if walking isn't possible.

3. Minimize Light Exposure in the Evening

Before artificial light, it got dark after sunset, signalling our bodies to prepare for sleep. Electric lights and screens can make it seem like daytime 24/7, disrupting our circadian rhythm. Blue light, in particular, mimics natural sunlight and can trick your body into thinking it's daytime.
To help your brain recognize it's time for sleep, implement these light-reducing strategies into your evening routine:

• Limit Screen Time: Stop using blue light-emitting devices (like cell phones, TVs, and computers) a few hours before bedtime.
• Example: If your bedtime is 10:30 PM, stop using these devices by 8:30 PM.
  
• Use Dimmer Lighting: At night, opt for dimmer, warmer lighting to signal to your body that it's time to wind down.
• Example: Switch to warm-toned lamps or candles after 8:30 PM to help your body prepare for sleep.
  

4. Adjust Meal and Exercise Times

Late-night eating can reduce the length of the vital sleep stage, leaving you tired the next day. Exercise raises body temperature and endorphin levels, keeping you awake. Practicing healthy sleep habits, such as adjusting meal and exercise times, is crucial for resetting your internal clock.

• Exercise Earlier:
• Example: If you prefer evening workouts, finish exercising at least one to two hours before bed. If bedtime is 10:30 PM, complete your workout by 8:30 PM.
  
• Avoid Late-Night Eating:
• Example: Have your last meal at least three hours before bed. If bedtime is 10:30 PM, finish eating by 7:30 PM. If you need a late-night snack, opt for something light and healthy.
  

We've written about exercise & eat hacks here.

5. Limit Caffeine and Alcohol Intake

Caffeine keeps you alert, while alcohol sedates you, but both can disrupt your sleep cycle. Caffeine has a long half-life and continues to affect you during sleep, while both substances suppress REM sleep, leaving you tired even after sleeping.

• Caffeine:
• Example: Stop drinking caffeine about eight hours before bed. If bedtime is 10:30 PM, avoid caffeine after 2:30 PM.
  
• Alcohol:
• Example: Stop drinking alcohol about three hours before bed. If bedtime is 10:30 PM, avoid alcohol after 7:30 PM.
  
  

The Role of Your Sleep Environment in Circadian Rhythm

Sleep hygiene involves behaviours and conditions that promote better sleep by regulating circadian rhythms, which are essential for maintaining healthy sleep-wake cycles. Besides developing positive habits like consistent sleep and wake times and reducing blue light exposure before bed, creating a supportive sleep environment is crucial.

The Importance of Comfortable Bedding

Creating an ideal sleep environment starts with evaluating your bedding. Comfortable and clean sheets can significantly enhance sleep quality. Here are some guidelines for maintaining your bedding:

• Pillowcases: Replace once a week to ensure cleanliness and reduce allergens.
• Duvet Covers and Fitted Sheets: Replace every 2 weeks to a month to maintain a fresh sleep environment.
  

You can read more about it here.

Temperature Control

Maintaining a cool room temperature is vital for good sleep. Research suggests a more relaxed environment helps you fall asleep faster and stay asleep longer. You can learn more about optimal sleep temperatures here.