These processes begin in the womb and continue to develop through the first few years of life. When you are first born, your circadian rhythm exists primarily without environmental cues. Over time, your circadian rhythm matures and aligns with the day and night natural light cycles.<\/span><\/p>\n\n\n\n Light is the most potent regulator of your circadian rhythm. Your retina is the area in the back of your eyeballs with many light receptors, such as the rod and cone cells. Some of these cells also tell your brain what time it is based on the light input.<\/p>\n\n\n\n A type of light receptor in your retina called intrinsically photosensitive retinal ganglion cells (ip<\/em>RGCs), is what researchers believe communicates directly with your body\u2019s master clock.<\/span><\/p>\n\n\n\n This master clock is called the suprachiasmatic nuclei (SCN) in your hypothalamus. The SCN has about 20,000 nerve cells. It is your circadian rhythm acting like a pacemaker or clock pendulum for your body. The SCN then coordinates with various clocks throughout the body using hormonal and neural signals.<\/span><\/p>\n\n\n\n Your circadian rhythm is unique to you. Some people are naturally early birds, while others are night owls. This uniqueness is called your chronotype. <\/p>\n\n\n\n Environmental or behavioral cues, called zeitgebers, heavily influence the secondary clocks throughout your body.<\/p>\n\n\n\n What you do throughout the day and night trains these clocks. The tricky part is that the master clock generally doesn\u2019t change. So, if the cues you give your body throughout the day don\u2019t align with the SCN, your circadian rhythm becomes misaligned. <\/p>\n\n\n\n Think back to earlier times without electricity. There was only the sun’s natural light to regulate your circadian rhythm. Sunlight signaled people to wake up and to get sleepy as the daylight faded into the night. There were no alarm clocks to get you up earlier or screens to stare into at night. <\/p>\n\n\n\n Artificial light makes it easier to see and improves safety. Because light is the primary regulator of the circadian rhythm, it should be no surprise that light exposure at the wrong times can seriously affect your circadian rhythm. <\/p>\n\n\n\n We know that light exposure affects the circadian rhythm by examining melatonin levels. Melatonin levels in your body have their own natural cycle. They are low in the morning and throughout the day, and high at night.<\/span><\/p>\n\n\n\n When your photoreceptors in your retina receive cues via the hypothalamus that it is getting darker, your pineal gland begins to release melatonin to ease you into a calm state and ready for sleep.<\/span><\/p>\n\n\n\n A literature review of 13 studies examined the effects of light on circadian rhythm. Two main factors of light affect the circadian rhythm: intensity and color. Light exposure suppressed melatonin in all subjects. The more intensely bright a light was, the more melatonin it suppressed. It took roughly 30 minutes for their melatonin levels to recover after exposure.<\/span><\/p>\n\n\n\n When exploring various light colors, researchers examined the effects of blue, red, and green lights. Those subjects exposed to blue light experienced greater melatonin suppression than green light. And the longer the exposure, the more the blue light suppressed it.<\/span> <\/p>\n\n\n\n Intermittent exposure to red light during the night did not inhibit melatonin production.<\/span><\/p>\n\n\n\n When you use your smartphone, tablet, or other LED screens, you expose yourself to blue light that may shift your circadian rhythm. A literature review explored the effects of artificial light on circadian rhythm. They found that individuals who used their smartphones before bedtime experienced poorer sleep quality and took longer to fall asleep. Using \u201cnight mode\u201d on your device changes the color balance and may diminish the effects of light exposure.<\/span><\/p>\n\n\n\n While light exposure at night delays your circadian rhythm, morning light advances it. Sunlight is so powerful in anchoring your circadian rhythm because of its brightness. Sunlight is 200 times brighter than indoor light in direct sun and 50 times brighter in daylight. You might not notice these differences because your pupils dilate to adjust.<\/span> However, If you don\u2019t get any sun exposure during the day, exposure to artificial blue light from screens and light bulbs at night can strongly disrupt your circadian rhythm. <\/p>\n\n\n\n When your circadian rhythm either advances by beginning earlier in the day or is delayed at night, it is called phase shifting. Even as short as five minutes or intermittent flashes of bright light exposure can shift your circadian phase.<\/span><\/p>\n\n\n\n Hormones that influence eating, digestion, and elimination fluctuate based on day-night cycles: <\/p>\n\n\n\n When your meal-eating behavior doesn\u2019t align with your natural rhythm, it can lead to circadian misalignment.<\/span><\/p>\n\n\n\n The largest body of studies on the effect of mealtimes on the circadian rhythm is with night shift workers who naturally eat out of phase. They also have higher occurrences of<\/span>:<\/p>\n\n\n\n In a study aimed at deepening understanding of meal timing on circadian-related rhythms, 20 subjects ate dinner at either 6:00 p.m. or 10:00 p.m. with the same fixed sleeping time from 11:00 p.m. until 7:00 a.m. Those who ate a late dinner experienced a four-hour shift in the postprandial period responsible for energy metabolism, which overlapped with the sleep phase.<\/span><\/p>\n\n\n\n While the shift in meal timing did not affect participants\u2019 sleep patterns, it did result in metabolic changes, such as an increase in glucose intolerance and a reduction in fatty acid breakdown.<\/span> Chronic recurrence of these conditions may promote obesity. <\/p>\n\n\n\n Daily physical activity, especially at the same time each day, strengthens your circadian rhythm.<\/p>\n\n\n\n A recent meta-analysis examined the effects of physical activity on the circadian rhythm. Overall, researchers found that physical activity directly strengthens the output from the SCN to decrease circadian rhythm disruption. When exercise occurs at the same time during the day and for the same duration, this further strengthens the circadian rhythm.<\/span><\/p>\n\n\n\n The same meta-analysis found that exercising outdoors increases exposure to natural bright light and helps align the circadian rhythm. Physical exercise is most effective when it is voluntary and fun.<\/span> <\/p>\n\n\n\n One aspect of the circadian rhythm that physical activity directly affects is your body temperature. Your body temperature naturally fluctuates throughout the day with a change of about 1.8 degrees Fahrenheit or one-degree Celsius from day to night.<\/span> <\/p>\n\n\n\n Higher levels of physical activity result in a more synchronized temperature rhythm throughout the day and night.<\/span> When this rhythm is out of whack, it can result in sleep disturbances and disruptions in your immune system.<\/span><\/p>\n\n\n\n The time of day you exercise is important for maintaining a proper rhythm for energy metabolism. <\/p>\n\n\n\n A literature review of 66 studies explored this very topic. It turns out that what\u2019s best for you depends on your chronotype. Early birds perform better in the mornings, and night owls perform better in the evenings. Early birds exercising in the evening may affect their sleep pattern.<\/span><\/p>\n\n\n\n Another study of 48 fit young adults highlights that morning or early afternoon exercise can shift your circadian rhythm forward and stimulate earlier melatonin release. The effect disappears when exercising after 4:00 pm and can delay circadian rhythm when exercise takes place after 7:00 pm.<\/span><\/p>\n\n\n\n We all know that sleep is critical<\/a>, and it\u2019s the most overt action of your circadian rhythm. What time you go to sleep at night can either align or misalign your rhythm. <\/p>\n\n\n\n A meta-analysis examining sleep timing and circadian rhythm tells us it\u2019s relatively simple: your chronotype determines your best timing.<\/span> If you avoid other factors like bright or blue light exposure, and eating and exercising late in the day, you can feel confident in listening to and following your body\u2019s cues for sleep. <\/p>\n\n\n\n Maintaining a consistent bedtime is the most important thing to ensure a healthy circadian rhythm.<\/span> <\/p>\n\n\n\n Your circadian rhythm regulates many physical and biological processes and, if disrupted, your health can be seriously affected. When your behaviors (like eating, bedtime, and meal times) and your environment (like artificial light exposure) don\u2019t align with your body\u2019s natural circadian rhythm, it creates a misalignment in your tissues and organs.<\/span><\/p>\n\n\n\n The majority of us are at risk for circadian disruption<\/span>:<\/p>\n\n\n\n If you are a night owl, you\u2019re even more likely to experience circadian disruption because social and professional responsibilities tend to occur during hours more aligned to early birds.<\/span><\/p>\n\n\n\n How circadian disruption affects you depends on whether it is short-term or long-term. Short-term disruption, like experiencing jet lag or a change in sleep schedule based on a work week vs. a weekend can result in<\/span>:<\/p>\n\n\n\n Long-term circadian disruption puts you at higher risk for<\/span>:<\/p>\n\n\n\n Keep in mind, these conditions involve many factors and unhealthy circadian rhythm is only one of them. <\/p>\n\n\n\n Hormone secretion, core body temperature, and metabolic activity determine your performance in any given activity. When your circadian rhythm is disrupted, you become less alert and have decreased cognitive function.<\/span><\/p>\n\n\n\n A meta-analysis explored the effects of circadian disruption on performance. Healthy subjects following normal light-dark schedules had the highest daytime physical performance and efficiency levels. These levels began to decrease in the evening and reached the lowest level by 2:00 am. This is also the time when your body temperature reaches its lowest.<\/span><\/p>\n\n\n\n With decreased performance comes an increased risk of accidents and safety concerns. Major disasters such as the Exxon Valdez oil spill and the Chernobyl nuclear accident happened during these late-night hours, making it very possible that circadian dysfunction played a role.<\/span><\/p>\n\n\n\n So now that I\u2019ve got you possibly concerned about your own health habits and potential risks in your life, read on to the next section to find out how to get you and your circadian rhythm back on track. <\/p>\n\n\n\n It\u2019s pretty easy to knock your circadian rhythm out of sync. Whether you\u2019re experiencing jet lag, spending a night out with friends, having a late meal, or disrupting your circadian rhythm in some other way, the good news is that it\u2019s not too late to reset it. It will take some effort and a good dose of consistency. This is what you need to do:<\/p>\n\n\n\n Go to bed and wake up at the same time. Every night. Even on the weekends. And do it all while listening to your body\u2019s natural clues. <\/p>\n\n\n\n It\u2019s unreasonable to think you can shift it in just one night. Start gradually by going to bed earlier by about 15 minutes each night and waking up about 15 minutes earlier each morning until you reach your target time. <\/p>\n\n\n\n A study of 23 healthy young adults compared the effects of unstructured and structured sleep on the circadian rhythm. Compared to unstructured sleep, when subjects on a sleep schedule experienced<\/span>:<\/p>\n\n\n\n![\"time](\"https:\/\/bioptimizers.com\/blog\/wp-content\/uploads\/2023\/03\/1-1-1024x689.png\")
<\/figure>\n\n\n\nCircadian Rhythm Zeitgebers Or Things That Influence Your Circadian Rhythm<\/h2>\n\n\n\n
1. Light Exposure<\/h3>\n\n\n\n
2. Mealtimes<\/h3>\n\n\n\n
![\"woman](\"https:\/\/bioptimizers.com\/blog\/wp-content\/uploads\/2023\/03\/2-1024x686.png\")
<\/figure>\n\n\n\n3. Physical Activity<\/h3>\n\n\n\n
4. Bedtime<\/h3>\n\n\n\n
What Happens When The Circadian Rhythm Is Disrupted?<\/h2>\n\n\n\n
How To Reset Your Circadian Rhythm<\/h2>\n\n\n\n
![\"man](\"https:\/\/bioptimizers.com\/blog\/wp-content\/uploads\/2023\/03\/3-1024x846.png\")
<\/figure>\n\n\n\n1. Maintain A Regular Sleep Schedule<\/h3>\n\n\n\n
![\"BIOptimize](\"https:\/\/fb-v1.cdn-bio.com\/assets\/uploads\/ad85-047d-5c16-4473_mag-dream-sb-desktop.png\")
\n<\/picture>\n<\/a>\n