Press the Reset Button on Your Circadian Rhythm

Circadian rhythm is our natural sleep-wake cycle mechanism. This 24-hour cycle is influenced primarily by changes in light during the day. As the day ends and the sun goes down, we typically become more tired. Conversely, morning light wakes us up. Important hormones are released during this cycle that influence our feelings of wakefulness and fatigue. Cortisol is released in the morning hours (beginning at about 3-4 am) to prepare us to wake. Melatonin is released in the evening (from about 8 pm-11 pm) to induce sleepiness. Our brains contain a master clock known as the suprachiasmatic nucleus (SCN). The SCN is a group of nerve cells that receives light through the eyes. Light or darkness triggers the release of cortisol or melatonin coordinated by the SCN. 

The timing of our exposure to light throughout the day is critical. Too much artificial light throughout the evening or not enough sunlight during the day can impair melatonin production. Cortisol and melatonin production can also be affected by chronic stress and irregular sleep schedules.

Another key chemical in the brain related to sleep is adenosine. Adenosine builds up in our brains throughout the day, reaching its peak concentration at night, causing us to feel sleepy. It then begins to level off while we sleep. 

(To view an in-depth discussion of the physiology of sleep and sleep stages, click here.)

Protecting the healthy functioning of these chemicals in the brain helps to ensure that we are getting enough high quality sleep. Healthy sleep supports our immune system, helps prevent chronic disease, and maintains high-level cognitive functioning. Our brains also conduct a vital detoxification process at night, which requires adequate sleep to work effectively.

Now that we have established how sleep cycles function optimally, let's look into the day to day obstacles we face that may impair this process. 

Light:

We've discussed that light is the primary influence on circadian rhythms. Many modern advances can interfere with getting enough of the kind of light we need at the right times. Here are some ways to ensure your daily exposure is helping you rest well.

• Get outside in the morning and soak in some a.m. light: Even just 30 minutes of sunlight in the morning can help regulate your sleep-wake cycle. Spending time outside in general and getting exposure to natural light can help reset your internal clock and result in faster sleep onset and higher quality zzz's.

• Avoid blue light emissions from electronic devices within 2 hours of bedtime:  This includes smartphones, tablets, computers, and TVs. Blue light can interfere with melatonin production, sending signals through the SCN that it is still light outside, delaying sleep onset. If you can't avoid devices close to bedtime, you may want to try using blue light blocking glasses. Many devices also have a "night mode," which will dim the lighting on your electronics and give it an orange hue. This will mitigate the effects of light exposure late at night.

• Turn off or dim bright lights in the house in the evening: Dimming the lights in your house a couple of hours before bedtime can signal to your body that it's time to prepare for rest. Also, make sure to eliminate as much light as possible in your room while you sleep.

Caffeine

Many people use caffeine as a stimulant to help them feel alert in the morning and throughout the day. Unfortunately, caffeine blocks the receptors for adenosine in the brain. As a result, we are likely to feel awake later into the evening and have difficulty getting to sleep. 

Some people are more sensitive to caffeine's effects than others, and certain lifestyle habits can impact metabolism timing (smoking and pregnancy are examples). Typical recommendations include stopping caffeine consumption at least 6 hours before bed. If you are having trouble sleeping, stopping earlier in the day or cutting down on the amount of caffeine consumed can help.

Signs caffeine may be problematic for you include: inability to fall asleep, nighttime anxiety, frequent awakenings, and feeling excessively sleepy during the day.

Regulate Your Sleep Schedule

Our very busy lives often affect the timing of our sleep. Unfortunately, inconsistent sleep and wake times can throw off our circadian rhythm. If possible, it is best to go to bed and wake up at the same time each day (or shoot for within 1-2 hours of your usual time).

Avoid naps during the day if you can, or keep them to 20 minutes or less and take them before 5 pm. Longer naps may reduce the brain's adenosine concentration, making it hard to fall asleep at bedtime.

Exercise

Daily movement can be beneficial for regulating sleep. However, activity late in the day may cause insomnia in some people. Exercise raises heart rate, core temperature, and adrenaline, which can keep you awake. If you like to exercise in the evening, and you suspect it may be interfering with sleep, it might be best to try something low impact like yoga or stretching. Doing light exercise like yoga can also help alleviate stress, which contributes to better sleep.

Alcohol

It may seem like alcohol would help with sleep because we often feel relaxed and tired when we drink it. Unfortunately, as the liver metabolizes alcohol during the night, you are more likely to experience a significant disruption in sleep duration and quality. We cycle through 4 different stages of sleep each night. (N1, N2, Deep Sleep, and REM) Each stage is critical, not only for detoxifying the brain and our body but also for feeling rested during the day. Because alcohol makes us feel sleepy, it can cause us to go into the deep sleep stage faster, thereby cutting REM shorter. Avoiding alcohol when trying to reset circadian rhythms is best, but sticking to 1 drink per night a few hours before bedtime may help in the absence of abstinence.

Stress Management

Most of us are aware that stressful times can keep us up at night. But when that stress becomes chronic, it can interfere with cortisol production and timing, which affects energy levels. 

As we mentioned earlier, cortisol begins to rise in the early morning hours, signaling the body that it is time to wake up. After a spike in the morning, cortisol begins to decline gradually throughout the day and then levels off close to bedtime. If you are chronically stressed, cortisol production can sometimes lag in the morning, causing extreme fatigue. Or it may spike in the evening, delaying sleep. Meditating and breathing exercises can be an effective strategy for alleviating stress, helping to return cortisol to normal functioning. Evaluating significant stressors in your life and whether they can be mitigated can be an important act of self-care.

(click here and here to see instruction on two great breathing exercises!)

We often focus on diet and exercise when thinking of ways to improve our health but sleep is just as important. Trying to tackle just a couple of these suggestions could have you counting more sheep in no time!