Sleep is a curious thing. For decades, many considered sleeping to be a poor use of their time. Yet, a growing body of evidence now points to the importance of sleep in relation to many facets of health and wellness. Sleep deprivation has been linked to heart disease,1 accidents2 and cognitive impairment.3
A lack of sleep increases your risk for Alzheimer’s disease4 as well as insulin resistance,5 which is the root cause of many chronic conditions. Sleep quality and quantity are important to your health, as demonstrated by one study that showed that interrupted sleep may be as dangerous as getting no sleep at all.6
How you wake up is also important, it turns out. The time after waking up, when you’re still groggy, is called sleep inertia. During this time most of us aren’t performing at our best.7
The Sleep Council describes sleep inertia as a period that lasts from five to 30 minutes, but sometimes as long as four hours.8 Basically, it’s a time of transition between being asleep and being fully awake and alert, marked by “an increase of sleepiness, confusion, disorientation of behavior and deterioration of work performance.”9
How You Transition Out of Sleep Affects Alertness
A research team from the Royal Melbourne Institute of Technology University in Australia gathered data on sleep inertia and the relationship to how you transition from sleep to wakefulness.
The Australian team found that how you transition from being asleep to being awake has an impact on your ability to be alert in the coming hours, overcoming sleep inertia. The study10 was published in PLOS|One and suggested the sounds you hear as you wake up have an influence on your initial daytime performance.
They used an online questionnaire to gather information from 50 participants who answered questions about what they preferred to hear when they woke up, how they felt about the sound and their perception of symptoms of sleep inertia they experienced after waking.
Interestingly, their analysis of the data did not show a relationship among the three. But they did find that sounds that were identified as more melodic (not the standard “beep beep” from an alarm clock) were associated with reported reductions in the respondents’ perceptions of sleep inertia.
Sounds that were ranked as “neither unmelodic nor melodic” were associated with an increase in sleep inertia. While this data may help you appreciate being more alert first thing in the morning, it may be even more important for first responders who may be called from a deep sleep to an emergency requiring quick, clear thinking. Lead researcher Stuart McFarlane commented in a press release:11
“If you don’t wake properly, your work performance can be degraded for periods up to four hours, and that has been linked to major accidents. You would assume that a startling ‘beep beep beep’ alarm would improve alertness, but our data revealed that melodic alarms may be the key element.
This was unexpected. Although more research is needed to better understand the precise combination of melody and rhythm that might work best, considering that most people use alarms to wake up, the sound you choose may have important ramifications.
This is particularly important for people who might work in dangerous situations shortly after waking, like firefighters or pilots, but also for anyone who has to be rapidly alert, such as someone driving to hospital in an emergency.”
What’s Your Sleep Cycle?
When you sleep your brain cycles through several phases. A full cycle in healthy sleep will last from 90 to 110 minutes.12 Each cycle has several stages of non-rapid eye movement (NREM) and rapid eye movement (REM) sleep.
A full sleep cycle starts out in light sleep and progresses through to deep sleep, then reverses back from deep to light sleep before entering REM. You cycle through each of these stages four to five times during the night, and this cycling is tremendously important, from both a biological and psychological perspective.
- Stage 1 — This is the lightest stage that is sometimes called a drowsy sleep stage. It’s during this stage you’ll sometimes feel like you’re falling as your muscles relax and your brain slows. Occasionally you’ll experience muscle spasms that may temporarily wake you.
- Stage 2 — During this stage of NREM sleep brain waves continue to slow and your body temperature and heart rate begin to drop.
- Stage 3 — This is deep NREM and is the most restorative stage. Awakening during this stage is rare and is when most sleepwalking and sleep talking occur.
- REM — This is commonly known as the dreaming stage when you have rapid eye movement from side to side. You can wake up more easily during REM, but it will leave you feeling groggy.
You will usually go through three to five REM cycles in the night and end with one right before waking. If you are awakened before completing a REM cycle you go through a period of sleep inertia that can last several hours.
Importance of Light, Melatonin and Rhythm to Feeling Rested
Your sleep cycle and how rested you feel when you wake up are partially dependent on how much light you get in the morning and at night, your melatonin production and your circadian rhythm. Let’s start with light.
During the daytime hours, sun light and blue light from your digital devices may help boost your attention span and mood.13 But, they likely have a similar effect at night when your body is trying to slow down and sleep. Unfortunately, the proliferation of digital devices and low energy lights has boosted your exposure to the blue light wavelength at all hours of the day and night.
The second effect blue light has is to shut down your production of melatonin, a hormone important to the quality of sleep you get. This means your exposure to blue light boosts your mood and energy and shuts off melatonin, factors that affect your sleep quantity and quality. This helps manage your circadian rhythms in the morning, but it’s something you want to avoid before going to bed.
These two factors — blue light and melatonin — play roles in your circadian rhythm, a term used to describe the 24-hour cycle of physiological processes, including sleep and wake cycles.14 For most people, the biggest dip in energy comes between 2 a.m. and 4 a.m. when most people are asleep, and within the first two hours after lunch.
Your circadian rhythm is controlled by the pineal gland, a small area in your brain, that is in turn affected by light. When your eyes see dark, a signal is sent to release melatonin, which helps you fall asleep faster and more soundly.
But with exposure to blue light at night, your melatonin production is slowed and your quality of sleep is reduced.15 In other words, each factor plays a significant role in the quality and quantity of nighttime sleep.
Working the Night Shift Adds a New Burden
Those who work the night shift may have personal experience with a reduction in their melatonin levels early in the morning as they drive home from work, just before they hope to fall asleep. In this short video, Dr. James Hamblin takes a humorous view on some of the options night shift workers have to reduce the effect on their body.
While flipping your sleep-wake cycle on its head is damaging to your health, working the night shift consistently is better than doing it intermittently as it allows you to establish a regular sleep-wake schedule. If you do work night shifts, then there are several strategies that may help:
• Blue-blocking glasses — When the objective is to fall asleep once you get home, you don’t want to be exposed to blue light first thing in the morning. Consider wearing blue blocking sunglasses as you drive home and until you go to bed.
• Blue light when you wake up — You’ll also want to trigger your body to shut off melatonin when you wake up to go to work. The best blue light is from the sun as it is balanced. But obviously the sun is not up if you are getting up at night. So I suggest creating an artificial day-night environment by using a conventional clear incandescent bulb as well as a cool white (blue enriched) LED bulb.
You need both, not one or the other, as the LED will give you the blue and the incandescent will give you the balancing red and near infrared spectrum. You will only need to use the bluish LED light for 15 to 30 minutes, to help establish your new sleep wake cycle when you wake up.
Remember that it will be virtually impossible to imitate the full-spectrum and brightness of natural sunlight, even with a high-quality UV lamp, cool white LED bulbs and bright incandescent lights.
• Black-out curtains and sleep mask — Regular curtains don’t block the light from outside. Black-out curtains and a sleep mask will help boost your melatonin production. Shut off any computers, cell phones, alarm clocks or other pieces of digital equipment that emit light or electromagnetic fields that may jeopardize quality sleep.
• Pay attention to mitochondrial health — Strategies such as optimizing your vitamin D, nutritional ketosis, intermittent fasting, exercise and supplements are factors I discussed in an interview with Rhonda Patrick, Ph.D., in “How Your Mitochondria Influence Your Health.”
• Avoid sleeping pills — The side effects may cause more harm than good. Better alternatives include using Emotional Freedom Techniques (EFT), listening to a brainwave synchronization tape or trying a natural sleep remedy that can help you relax without the side effects.
Tips to Help You Sleep Soundly
Lost sleep has a cumulative effect on your health.16 Using an alarm with pleasing musical sounds to easily transition from sleep to being awake is just one aspect of protecting your health and safety. If you struggle with falling asleep or staying asleep, you’ll want to consider the tips from “Top 33 Tips to Optimize Your Sleep Routine.”
At every different stage in life, humans have different requirements for sleep. You’ll discover how much is necessary for everyone in your family and you’ll find a list of health conditions associated with sleep deprivation in the article.
By optimizing your bedroom, preparing yourself for sleep, undertaking a few lifestyle suggestions to enhance your sleep and using a melodic alarm clock to transition into your day, you may be surprised by how good you feel each morning.