Health – Living in Circadian Rhythm

We are designed to have 24-hour rhythms to our physiology and metabolism. Our bodies have an internal clock that we refer to as our circadian rhythm. This internal clock is influenced primarily by light exposure during the day and darkness during the night. Ideally, sunlight at sunrise “sets the clock” while darkness after sunset “winds the clock down.” We have a wake cycle, activated by light exposure, during the day and a sleep cycle, activated by darkness, at night. Many organs show daily changes in their function based on circadian influences. Genetic expression, which genes are turned on and which genes are turned off, is also directly influenced by circadian rhythms. In fact, thousands of genes change their expression according to circadian rhythms throughout the day and night.

Sunlight synchronizes all cells and organs in the body and influences cell energy production. During the day, we need to be awake, energetic and active. In contrast, sunset and darkness initiates a sleep and repair cycle via the release of melatonin, so we rest and recover to allow repair processes to occur throughout our cells and organs.

This is how we are designed and there is no escaping it. We are meant to be awake and active from sunrise to sunset and to be recuperating and resting after sunset. In essence, we have a built-in schedule each day; there is a time to eat, a time to sleep, a time to digest, a time to repair, basically a prime time for everything. When we live in accordance with our internal rhythms we optimize health. … Of course, with our modern lifestyle and 24/7 workload, light exposure, computers, television, travel and constant access to food, it is unfortunately way too easy to disrupt our internal clocks. Too often we are eating when we should be fasting, awake when we should be sleeping, exposed to light when we should be releasing melatonin and winding down for the night. Our modern world with all the breakthroughs, benefits, and conveniences, can be damaging to our health in myriad ways.

Circadian rhythm disruption accelerates the aging process while circadian rhythm synchronization slows the aging process.

Our mission is to slow the deterioration in our health that occurs with aging so we can extend our healthspan – the number of years that we live in a healthy state – rather than struggling with disease and degenerative conditions.

The key is to feed, train, and rest our body as originally designed.

Our anti-aging lifestyle, focusing on sleep, nutrition, movement and stress levels, can modulate the aging process. We strive to have a lifestyle that is congruent with our internal clocks to allow us to extend our healthspan.

Everything we do with our lifestyle is meant to restore harmony in our bodies so we can ignite our internal antiaging mechanisms, while simultaneously combating accelerated aging forces. Optimizing our anti-aging mechanisms, such as stem cell activation, genetic expression, DNA repair … requires that we restore this internal harmony with our circadian rhythms.

Our bodies are constantly adjusting to maintain homeostasis. Homeostasis is a healthy state preserved by incessant refinements of biochemical and physiologic pathways in response to external and internal stimuli.

Homeostasis is our body’s ability to listen and immediately respond to what we do, think, eat, as well as how we act and react. As examples, if we perceive stress, real or imagined, our stress response is switched on. If we relax or sleep, then our stress response is turned off and the relaxation response is activated. If we move or exercise, the body reacts positively and builds. If we are excessively sedentary, the body responds detrimentally and breaks down. When homeostasis is disrupted we have suboptimal function and accelerated aging.

Circadian desynchronization results in chronic stress, leading to accelerated aging, muscle and bone loss, increased fat storage, cognitive impairment and immune dysfunction.

With delicate precision our circadian rhythm impacts our metabolism, physiology, energy level, hormone levels, mood and pace of aging.

So how do we live in balance with our circadian rhythm?

We must balance our:

  • Sleep and wake cycles.
  • Eating and fasting intervals.
  • Stress and relaxation.
  • Exercise and recovery periods.


Quality sleep is imperative for physiologic stress reduction as well as brain and body repair. Cells repair, memories consolidate, and hormones balance while we sleep. Sleep deprivation, all too common with our hectic schedules, leads to rapid aging, cognitive decline, weight gain and muscle loss.

It is crucial to maintain a consistent sleep/wake cycle to optimize restorative sleep. Go to bed every night at around the same time, keeping the same schedule on weekends. Strive for 7–9 hours of continuous sleep at night. Turn down bright lights. Too much light at night may make one unable to fall asleep at bedtime. Protect against blue light emitting screens and phones in the evening by wearing blue light blocking glasses or utilizing blue light screen protection on your phones and computers. Blue light exposure decreases melatonin release disrupting sleep. Turn off devices at least two to three hours before retiring. Sleep in a cool, dark, quiet environment. We build collagen, repair DNA, release restorative hormones, and activate stem cells during high quality sleep.

Intermittent fasting/Time restricted eating

The body has established schedules to perform functions such as digestion and nutrient absorption at certain times of the day. If daily routines and schedules do not match the body’s schedules, an imbalance may occur which can lead to fatigue, weight gain, stress, and even illness. To have proper nutrition, 50% depends on the correct choice of food and the other 50% depends on when and how it is consumed. Eating at the wrong times interrupts the circadian rhythm, which alters the ability to have a healthy metabolism and a powerful autoimmune response. Breakfast should be the biggest meal of the day with the smallest meal being consumed at dinner.

Restrict your eating window each day to 6 to 12 hour intervals with intermittent fasting. Our digestive tract, digestive processes, and metabolism are affected by circadian rhythms, so close the kitchen at night! Eating late at night strains organs involved in digestion forcing them to work when they are supposed to be repairing. Simply not eating a late dinner, for example, can help with weight loss and digestive issues such as heartburn and irritable bowel symptoms.


Elicit the relaxation response with deep breathing techniques, walking, relaxing music, or whatever your preference. Chronic stress, with the resulting continuous release of destructive stress hormones, overwhelms homeostasis, impairs digestion, increases blood sugar levels and fat storage, while simultaneously breaking down muscle and bone. When we activate the relaxation response we decrease cortisol, lower inflammation, slow telomere loss, and halt this erosive impact of chronic stress on our health and pace of aging: Relax, to reset your health.


Focus your diet on real food sources such as nuts, seeds, berries and vegetables. Avoid pastas, cakes, cookies, sweet breads, candy, corn syrup, soda, juices, processed oils and refined carbohydrates. Processed foods accelerate aging. Real foods slow aging: Eat clean for health!


Break the cycle of chronic stress by being present, mindful and by living your life with love and gratitude. We all have much to be thankful for. Enjoy your family, friends and pets each day. Share cherished memories with your loved ones: Be present!


HIIT, High-intensity interval training, alternating short bursts of activity with quick recovery periods, is a remarkable antiaging modality via several mechanisms, including stimulating HGH (growth hormone) release, increasing BDNF (brain-derived neurotrophic factor), our brain fertilizer, and activating stem cells. HIIT is a time efficient exercise technique that optimizes brain and body health while avoiding the excessive stress of prolonged exercise sessions: Exercise to optimize.

Since fasting acts as an exercise mimic, we can accrue additional antiaging benefits when we exercise while fasting: To really optimize, go fast while fasting!

Keep your schedule on track as much as possible. This can make a crucial difference in how your internal clock functions and how you feel.

Dr. Frank Comstock, M.D., ABAARM, FACEP.

Excerpts from

“The mind does not wear out nor break down so often on account of diligent employment and hard study as on account of eating improper food at improper times, and of careless inattention to the laws of health. Irregular hours for eating and sleeping sap the brain forces.” Mind Character, and Personality, vol. 2, 388.

“There should be regular hours for rising, for family worship, for meals, and for work. And it is a religious duty … to maintain this by precept … by a firm example.” Manuscript Releases, vol. 8, 327.