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Improving Sleep and the Role of Your Central Clock


Getting good quality sleep can become a tall order as we make more trips around the sun, increase our responsibilities, add to our “to do” lists, take care of older family members, carve out time for self-care/hobbies, etc… the list goes on…


Why should we be concerned about sleep? I’m glad you asked…Poor sleep can have multiple health effects on our bodies:


·      Poor Immune system function

·      Mood dysfunctions

·      Poor pain threshold

·      Increased risk of cancers (breast, prostate, colon)

·      Increased oxidative stress

·      Poor DNA repair (700 genes affected)

·      Increased car crash deaths in teens

·      Impaired memory & learning/retention of new information

·      Impaired cognition

·      Lowered testosterone/hormone imbalance/fertility issues

·      Lower energy production

·      Increased heart disease and stroke

·      Obesity/diabetes


Sleep disorders are very common. Some statistics include:

·      50-70 million adults have a sleep disorder

·      48% report snoring

·      38% unintentionally fall asleep during the day at least once in the preceding month

·      4.7% reported falling asleep during driving at least once in the preceding month


Sleepy people are everywhere!! We need to understand how to improve our sleep to improve our health. I’ve heard people say, “I’ll sleep when I die…” Well, you might get there sooner than later if you have that mindset about sleep.


Sleep hygiene is the term used to describe “best practices,” to get better sleep. It’s the habits and behaviors we incorporate throughout our days to optimize our health, not just what you do in the hour or two before bedtime that promotes beneficial sleep. It’s what we do every day and night that makes or breaks our quality and quantity of sleep.



 Meet your Central Clock

There are lots of tips and tricks to better sleep. One tip that isn’t always highlighted is better sleep follows the “Circadian Balance or Rhythm.” The Circadian balance is regulated by the “Central Clock” which synchronizes behavior and physiology of the body, anticipating and adapting to the outside environment. This central clock lives in the brain and acts as our sleep “pacemaker,” following a 24 hour schedule and regulating our sleep-wake cycle.


During the 24 hour cycle, hormone levels fluctuate in response to light, particularly the two hormones cortisol and melatonin. Cortisol levels rise in the morning hours and fall in the afternoon and evening hours to prepare for sleep. As you can see on the chart, cortisol and melatonin levels oppose each other. Think of it as "cortisol follows the sun and melatonin follows the moon." Morning cortisol levels are high to stimulate wakefulness, whereas the melatonin levels are low. While during the evening hours melatonin levels are rising and cortisol levels are falling. The central clock, if stimulated properly in the morning, starts this sleep-wake cycle or circadian balance.


Natural or artificial morning light stimulates the melatonin levels to slowly rise so they are at peak levels when it’s time to wind down and get sleepy. Morning light stimulation is critical in establishing melatonin production throughout the day, creating circadian balance of cortisol and melatonin hormones. Morning light starts setting the timer on melatonin release 14-16 hours from light exposure. If you live in a zone where morning outside light is difficult to experience, some find help with artificial light sources such as light boxes, light visors and dawn stimulators.



Exposure to sunlight between the hours of 7am to noon helps set the central clock. Researchers recommend a minimum of 30 minutes and up to 120 minutes of exposure time for at least one week. Some of the studies in this analysis lasted several months and recommended the light intensity between 2500 to 10,000 lux:



And…the big question about supplementing melatonin…Yes, it can be helpful for some. It’s best to understand the good and bad of this hormone. According to Dr. Matthew Walker, PhD, sleep study expert and author of the book, “Why We Sleep,” melatonin is an unregulated substance which can have variability in the dose described on the product label. When you think you’re taking a certain dosage, you could very well be taking more or less. Also, many people feel that higher dosages (5-10 mg) are better for sleep issues. Dr. Walker recommends 0.5 mg – 2 mg for improving sleep. Check out his YouTube video here:


Instead of relying supplemental melatonin, why not try resetting your central clock for improved sleep? It just might be the missing link you need to get better sleep!


Type: Morning Sunlight or other light source

Intensity: 2500 to 10,000 lux

Time: Between 7am- Noon

Duration: 30-120 minutes per day or as needed


Stay tuned for Part 2: Improving Sleep and the Role of Your Blood Sugar Levels


Having issues with getting good sleep? Reach out for a complimentary 30 minute Discovery Call to see if you are a good candidate for a Functional Medicine Assessment.


Thanks for reading!


Dr. Rebecca Hoeck PT, DPT





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