Each person has their own unique inner sleep schedule called the circadian cycle. It tells you when you should fall asleep each night and when to wake up each morning. But even the smallest hiccup in your life can affect your sleep schedule. Frequent offenders include staying up late with a fussy baby, working the night shift, and traveling across different time zones. If you are having problems concentrating or it seems extra difficult to get up in the morning, you could benefit from learning how to reset your sleep schedule.
The circadian cycle is also known as your inner sleep cycle. It is characterized by the physical, behavioral, and mental changes that occur during a 24 hour period (1). This includes the way you respond to darkness and light. Most living things have a circadian cycle, and yours is unique from everyone else's, meaning that the sleep habits that work for you may be different than they are for someone else.Your circadian cycle is different from your biological clock; however, they are related. The circadian rhythm is set by the biological clock, which is thought to be a group of molecules that interact in the body’s cells. You also have a master clock located just above the optic nerve in the hypothalamus that controls all of your body clocks so that they are synchronized (1).
The master clock is made up of a group of 20,000 nerve cells called the SCN, or the suprachiasmatic nucleus. Its job is to relay information to the brain from the eyes, such as light exposure. When the optic nerve senses there is incoming light, it tells the SCN not to produce melatonin because it assumes you need to be awake during the day. But when it’s dark, the SCN produces more melatonin to help you fall asleep at night.
Research shows that the circadian cycle has a genetic component that is predetermined in some people (1). Many natural factors in the body are responsible for producing your circadian cycle, but environmental triggers also influence it. The primary factor that drives your circadian cycle is exposure to light. This is mainly due to the release of melatonin, which is needed to stimulate sleep. Melatonin is released at night when it’s dark and is suppressed in the morning with exposure to light. When you are exposed to light at night, it affects your melatonin levels and ultimately prevents you from sleeping.
The circadian cycle is responsible for releasing hormones, controlling body temperature and influencing the sleep-wake cycle, among other things. When your circadian cycle is off, you may be more likely to develop a sleeping disorder, such as insomnia, as well as diabetes, depression, obesity, bipolar disorder, and seasonal affective disorder (1). Because the human body is sensitive to so many different systems, it is easy to throw one of them off when another is not working properly.
A poor night’s sleep goes beyond the usual symptoms of feeling groggy and being unable to concentrate the next day. Research suggests you become emotionless, or at least your face does (2). Your brain doesn’t work very well when it's tired. Lack of sleep has an effect on emotional and cognitive function. So even if you feel happy, your face remains neutral, which is often perceived as unhappy.
Not only do you become unable to express happiness, but you also become unable to recognize other people as being happy. Research shows that a tired brain may not be able to detect a happy face as well as a rested brain (2). People who are sleep deprived also don’t handle disappointment well, either (2).
It only takes one night of sleep loss for you to feel its effects. Research shows that a person who has a bad night’s sleep may experience something called “microsleeps” the next day (2). Microsleep occurs when a person experiences sessions of mini-sleep that last for approximately 30 seconds (2). The scary thing about microsleep is that the person essentially becomes blind even if their eyes are open because their brain isn’t processing enough information (2). Microsleeping is one of the reasons why driving while tired is so dangerous.
If you’ve ever felt a bit off when you don’t sleep well for a few days, you may be experiencing very mild stages of delirium. Delirium occurs when a person becomes disorganized. Extreme cases of sleep loss can make you feel that way. Research shows that patients who have been hospitalized in the intensive care unit for a long time may develop a condition known as ICU delirium (2). It is caused by continuous exposure to lights and sounds all day and night (2). While doctors are not sure if the loss of sleep causes the delirium, it is believed to be one of the reasons why people who have been hospitalized for a long time begin to act bizarrely. Hospital patients also tend to develop insomnia if they have been there for awhile (2).
Along with becoming delirious, lack of sleep can make you hallucinate or see things that aren’t really there (2). Hallucinations are often the result of the brain not being able to accurately interpret information, which commonly occurs when you don’t get enough sleep. While some people may not see full images of things that aren’t there, they may see flashing lights in their peripheral vision, which is just as dangerous while driving.
While it is rare, sleep loss may contribute to mortality in some cases. Research involving a series of animal studies found that sleep deprivation eventually lead to the death of lab rats (2). Another report showed that in 2012 a Chinese man died after being awake for 11 days (3). Although sleep deprivation is very unlikely to cause death, there is no question it can lead to several serious side effects.
The best thing you can do for your circadian cycle is to not let it get out of whack in the first place. But things like the birth of a baby, menopause, social obligations, or even constant stress make us feel like we’re off. Here are some tips for resetting your circadian cycle so you can return to your normal, high-functioning self.
1. Follow a bedtime routine.
Even if you didn’t have one before, it’s never too late to develop a healthy bedtime routine. Prepare your mind and body for rest by doing something relaxing that signals sleep, such as taking a hot bath, reading a book or listening to calm music. Avoid the temptation to check your phone, scroll the internet or watch television as the light emitted from these sources will keep you awake.
2. Keep your nights dark and brighten up your mornings.
Darkness tells your body when it's time to produce melatonin, which is a hormone that helps you fall asleep. If there is light on in your room at night or if you are exposed to an electronic device, it will tell your brain not to release melatonin. Keeping your room dark at night will help you fall asleep and stay asleep due to the regulation of melatonin.
You can use the same idea to help you wake up in the morning. When the alarm goes off, turn on all the lights in the room and open the blinds, so natural sunlight comes in. Exposure to sunlight will decrease melatonin to help you wake up and get your day started.
Physical activity is one of the best things you can do to help you fall asleep and stay asleep naturally. It relieves stress and is good for your mental and physical health. In addition to reducing sleep apnea (4), studies show that exercise also improves insomnia (5).
To reset your sleep cycle, try to exercise earlier in the day or first thing in the morning. It will help energize you throughout the day and help you rest easier at night. Exercising too close to your bedtime could keep you awake. Stretching, yoga or meditation is a good activity to do before bed because it’s calming and should help you wind down.
Research suggests spending 150 minutes each week exercising to help you sleep better at night and feel more awake during the day (6). Be sure to check with your doctor first if you’re unsure where to start. An exercise program should include both a cardio and resistance training plan to reduce stress, build muscle and burn fat, and help restore your body’s circadian cycle.
4. Eat light at night.
Many people make dinner their biggest meal of the day, but eating too late at night could be keeping you awake. Although your digestive system doesn’t stop working when you go to sleep, it’s possible to cause gastrointestinal discomfort if you feed it too much. Ideally, you should avoid eating large meals at any time of the day, but nighttime is especially important. It’s hard to sleep when your digestive organs are trying to process a large meal.
Aim for four to six smaller meals a day instead of three large ones to give your digestive system a break. Small amounts of food are easier to digest and shouldn’t keep you awake while you’re trying to sleep. Also be mindful of what you drink during the day and at night. An after dinner coffee can keep you awake while drinking alcohol can spike your blood sugar levels. Try eating a low-carb meal at night and sip on herbal tea or water to keep calories down and help you sleep.
5. Adjust to a new time zone before traveling.
If you're scheduled to travel across a few different time zones, adjust to your new schedule before you leave. A few days before your trip, start gradually going to bed closer to your new time.
For example, if you’re traveling somewhere that is six hours ahead of your current timezone, start going to bed an hour or two later each night. Adjust your wake up time to reflect your new sleep time, too. Try to do the same thing before your trip home so that you change back to your regular sleep schedule quicker.
6. Don’t jump around job shifts.
If you can help it, stick to one job shift. When you jump around from the first shift to the third shift, you can throw off your circadian cycle. Even if you have to commit to only working the night shift, it’s better than jumping around all over the place. When you’re leaving work during the day to head home, wear sunglasses to block out the light. When you get home, make your room dark to increase melatonin levels and try to get your full seven to nine hours of sleep.
7. Use a natural sleep aid.
You may want to consider using a natural sleep aid to get your circadian cycle back on track. Natural sleep aids are gentler than pharmaceutical brands with fewer, if any, side effects. One study showed that taking prescription sleep medications significantly increased the risk of certain cancers and death (7). The study also found that people who take prescription sleep medicines are four times more likely to die within 13 to 15 years than those who do not (8).
Along with an increased risk of death and cancer, there is evidence to suggest that prescription medications don’t work. A study funded by the National Institutes of Health showed that prescription sleep medicines only reduced the average time it took to fall asleep by less than 13 minutes and provided an average of 11 additional minutes of sleep (8).
Supplementing with melatonin at night may help your circadian cycle get the message that you want to go to sleep now. When combined with other relaxing herbs, such as valerian root, chamomile, and l-tryptophan, melatonin can help improve your quality of sleep.
A 2012 study found that subjects who took two milligrams of melatonin one to two hours before bed improved their sleep quality and length. They also reported being more alert the next morning and experienced a better quality of life because of it. Most importantly, the study found that subjects who took the melatonin had no withdrawal effects, side effects, or rebound insomnia (8).