Humans are considered monophasic sleepers — meaning that they sleep for a single long stretch (typically at night). This makes sense because the absence of daylight during the evening makes it impractical to work or do outdoor activities. Or at least it did before the evolution of artificial lighting. With the rise of the “night shift” and extended work hours, many people are adopting what’s known as a polyphasic sleep pattern, aka napping, which involves sleeping when schedules allow. The real question is: is napping good for you? Members of the World Sleep Congress say most likely; however, some research suggests that excessive amounts of sleep can do more harm than good.
A nap is defined as any period of rest that lasts for less than 50% of the average duration of an individual’s nocturnal sleep length. The primary types of naps, as defined by sleep scientists from the World Sleep Congress, are:
People may choose to take naps for a variety of reasons. While some nap in response to sleep loss, others simply nap for enjoyment (Broughton and Dinges, 1989).
Many studies have documented the potential benefits of napping, especially when it comes to optimizing performance during the day. Naps can:
Proponents of napping argue that this ritual can help maximize the amount of time you spend in rapid eye movement (REM) sleep, which is when dreaming, memory storage and mood regulation take place.
There is an art (and science) to napping. While there are some notable health benefits, researchers have discovered negative effects of napping too – specifically when naps are poorly timed or long-lasting. In these instances, naps can:
Recent research has also indicated that taking longer naps may increase your risk of having a stroke. There are actually three sleep patterns associated with naps and risk of stroke, including:
In contrast, individuals that get 7 to 8 hours of night sleep at night and opt out of napping during the day tend to have the lowest risk of stroke.
People are hardwired to feel a little tired in the middle of the afternoon when their circadian rhythm dips. Offhand, taking a short afternoon nap will not disrupt your normal seven to nine hours of sleep at night. However, some research suggests that excessive amounts of sleep can do more harm than good over time.
According to Matthew Walker, neuroscientist and author of Why We Sleep, we build up sleep pressure while we are awake during the day. This pressure is purposeful in that it makes falling and staying asleep at night easier. While resting, we release that sleepiness, almost like a valve on a pressure cooker, so that we wake up the next morning feeling refreshed (Business Insider). Excessive napping could act as a double-edge sword and disrupt your circadian rhythm, making it more difficult to get adequate sleep at night.
The key to mastering naps is to keep them short and have them at specific times during the day. The next time you’re feeling tired in the middle of the day, ask yourself the following questions:
Junk Light: The Dark Side of Blue Light
While we get natural and necessary levels of blue light from the sun, artificial light sources bombard us high levels of blue light day and night. This overexposure to blue light, what we term junk light, disrupts our circadian rhythm and depresses our melatonin production, the body’s main sleep hormone.
Our brain to starts our “sleep” phase, increasing melatonin and signals the body to:
Junk light exposure when traveling can disrupt your circadian rhythm. Long-term exposure to light at night which accompanies shift work is listed as a probable carcinogen by the World Health Organization. Light at night has shown to be highly associated with significantly the risk of hormone specific such as cancers of the breast and prostate.
The flickering wavelength of light associated with LEDs and compact fluorescent lights emit blue light that inhibits melatonin production but also create a unique glare that impacts your retina causing eye strain, headaches, and physical and mental fatigue.
Red light and darkness move leptin and ghrelin into patterns that are (context dependent) associated with less hunger, while blue light does the opposite and can move both into patterns associated with more hunger.
Increase in cortisol, the stress hormone, due to circadian disruption. Memory recall is impaired with consistent sleep deprivation and may leave you distracted and not performing your absolute best.
The Importance of Melanopsin Cells
Your body requires some blue light at the right time of day and from the right sources. That’s why we created TrueDark® Sleep Technology that gives you 24-protection from junk light day and night.
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