How to Regulate Your Circadian Rhythm for Better Sleep

Your circadian rhythm is your body’s natural 24-hour sleep-wake cycle. It plays an important role in sleep, hormone balance, nervous system function, and overall health. When your circadian rhythm is disrupted, you may find yourself exhausted in the morning but wide awake at night, struggling to fall asleep, or waking throughout the night.

Understanding Your Circadian Rhythm

Two important hormones involved in your daily rhythm are cortisol and melatonin. Cortisol should be higher in the morning and gradually decrease throughout the day, while melatonin should increase as the day goes on and be higher around bedtime.

This rhythm is regulated in part by the suprachiasmatic nucleus, often referred to as the body’s “master clock.” One of its biggest influences is light exposure. Light signals the body that it is time to be awake and alert, while reduced light allows the body to transition toward rest and sleep.

Signs Your Circadian Rhythm May Be Disrupted

One of the simplest ways to recognize a disrupted circadian rhythm is to look at how you feel at opposite ends of the day.

• Feeling extremely tired in the morning
• Not feeling energized when you wake up
• Struggling to feel sleepy at night
• Feeling more alert at night
• Having difficulty falling asleep because your brain won’t shut down
• Waking up throughout the night

How Your Daily Habits Affect Sleep

One of the biggest factors affecting circadian rhythm is light exposure, especially in the evening. Blue light can signal the brain that it is time to wake up and produce cortisol. Reducing screen time before bed or switching your phone and computer to a red-light setting can help decrease this stimulation.

Nutrition and blood sugar are also closely connected to cortisol. When blood sugar drops, cortisol can rise to bring it back up. Consistently eating throughout the day, with meals containing plenty of protein and fat, can help reduce the need for cortisol to regulate blood sugar. The approach described here is three meals a day about five hours apart, with not too many carbohydrates.

Exercise timing matters as well. Intense exercise can increase cortisol, so exercising very intensely late in the evening may make it harder to fall asleep. More intense workouts are better earlier in the day, while walking and other less intense movement can be a better fit later in the day.

Stress, Temperature, and Your Sleep Environment

Stress can disrupt the balance between cortisol and the parasympathetic nervous system. The vagus nerve plays an important role in the body’s calming response and in transitioning into a more restful state. Infections, gut issues, inflammation, and other factors that irritate the nervous system can also contribute to sleep issues.

Your environment matters, too. Temperature can influence how restful and sleepy you feel, and finding a comfortable sleeping temperature can make a significant difference. Social stimulation late at night can also make it harder to immediately transition into sleep.

Creating a Better Morning and Bedtime Routine

Supporting your circadian rhythm starts when you wake up, not just when you go to bed. Morning light exposure can help signal to your body that the day has begun. A consistent morning routine can reinforce that rhythm.

At night, the goal is to gradually slow things down. Eating about two hours before bed, avoiding intense exercise close to bedtime, taking a walk after dinner, limiting technology and blue light, and giving yourself time to read, relax, or spend time in prayer can all be part of a calming bedtime routine.

How to Improve Your Circadian Rhythm and Sleep-Wake Cycle

A healthy circadian rhythm depends on more than simply getting enough hours of sleep. Light exposure, cortisol, melatonin, blood sugar, nutrition, exercise, stress, nervous system function, temperature, and daily routines all play a role.

Creating consistent signals throughout the day—light and activity in the morning, balanced nutrition and movement during the day, and less stimulation in the evening—can help support a more natural sleep-wake rhythm.

If you are considering taking a prescription medication or adding any new therapies or supplements, be sure to communicate and work with a medical professional.