Weekly Articles

The 4 Stages of Sleep and Why They Matter

In scientific terms, sleep is a state of altered brain activity. During non-REM sleep, brain activity looks very different than it does when you're awake, but during the REM portion of your snooze, it actually looks very similar to an awake state. In all stages, though, there's a lot going on.

“Sleep, in a way, is still a big mystery to us,” says Michelle Drerup, PsyD, Director of Behavioral Sleep Medicine at Cleveland Clinic. “We know that in non-REM sleep and when there’s deep sleep, there’s physical restoration occurring, but in REM sleep, there’s still some debate. It is thought that we’re filing things away from the day and [engaging in] memory consolidation.”  

During sleep, there are also distinct physical changes in the body, such as changes in eye movement and muscular tension. Further variations in electrical activity in the brain show when each stage of sleep begins and ends. And speaking of those stages, there are four of them, plus the REM phase, and we cycle through them about four to five times each night if we’re getting a proper amount of shut-eye.

If you’re looking to sleep better naturally, you won’t want to miss these sleep tips that doctors recommend.

Sleep stage 1

Our breathing and heartbeat become regular, our muscles relax, and our body temperature falls. We become less aware of external stimuli, and our consciousness starts to withdraw from reality. The slightest noise is enough to wake you from this stage, and if you do indeed wake up, you might think you haven’t been asleep at all. You have likely experienced the sensation of falling suddenly, typical of this stage, and some people also experience twitching. Sleep stage 1 can last from five to 10 minutes, according to Cleveland Clinic.

Sleep stage 2

Sleep becomes deeper during this stage, and our muscles relax further. Physical sensations are dampened significantly, and our eyes do not move. Electrical activity in the brain occurs at a lower frequency than when we’re awake. About half of our total sleeping time is spent in stage 2, which means that we’re spending more of our repeated sleep cycles in this stage than in any of the others, according to the National Institute of Neurological Disorders and Stroke. Stages 1 and 2 are known as the light-sleep phase. Together, they last for about 20 to 30 minutes per sleep cycle. We return to stage 2 several times during the night. 

If you’re going to take a power nap, it is generally recommended that you wake up during this second stage of sleep. “A 15- or 20-minute nap tends to be really refreshing for people because your brain activity is not into the slow-wave activity of stage 3,” says Drerup. “When you go into that type of sleep, it's much more difficult to wake, you’re groggy, and you have sleep inertia.”

Sleep stages 3 and 4

We reach the first of our deep-sleep stages, stage 3, after approximately 20 to 30 minutes, and the second, stage 4, after about 45 minutes. At that point, the body is completely relaxed, and we are more or less completely disconnected from reality. If you want to wake someone from deep sleep, you need to make a lot of noise or shake them quite hard. Waking someone from stage 4 is almost impossible—a bit like trying to wake a hibernating bear in the middle of winter. This is the most restful part of the night’s sleep. Muscular activity decreases even further, and our eyes do not move. Stages 3 and 4 make up about 20 percent of our time asleep, but this proportion decreases as we get older. Here's how you can combat America's sleep-deprivation crisis—and get more shut-eye.

REM sleep

Between 80 and 100 minutes after falling asleep, the deep-sleep phase ends—something that is often accompanied by a change in sleeping position. Our sleep switches to stage 2 for a few minutes again before the brain abruptly switches to REM sleep, the dreaming sleep stage. Our heart rate increases, our breathing gets quicker, and the electrical activity in the brain creates small, rapid movements in the EEG, similar to those seen when falling asleep. Our muscles are completely relaxed, but our eyes make quick, darting movements while remaining closed. This is where the phrase rapid eye movement (REM) comes from.

Men occasionally experience erections during this phase, and women may have increased blood flow to the genitals. The production of digestive juices also increases. It is during REM sleep that we have most of our dreams. For adults, REM sleep makes up about 20 percent of a night’s sleep. The percentage is considerably higher for infants and small children.

When healthy people are in a state of REM sleep, the muscles of our body are deeply relaxed. If it wasn’t for this, we might act out our dreams, with potentially disastrous consequences. This is most likely the reason the brain puts the body in this deep state of relaxation bordering on paralysis (known as Antonia) during this stage. However, when a person is suffering from some conditions, such as Parkinson’s disease, REM Antonia does not occur and people can act out their dreams.

The sequence of sleep stages

Sleep follows a specific sequence of these different stages. We complete a sleep cycle and begin a new one approximately every 80 to 110 minutes, usually around 90 minutes. A night’s sleep begins with a light-sleep phase of varying duration, followed by the first deep-sleep phase of the night and a short REM phase. In the second half of the night, we spend a relatively shorter amount of time in deep-sleep phases while our REM phases tend to be longer. The final REM phase of the night can last for as long as 30 minutes or more. And then, we wake up.

The pattern of REM sleep changes as we grow older. During the first year of life, babies spend most of their time asleep in REM sleep. After the age of four, the proportion of REM sleep falls to about 20 percent of the night. People over the age of 60 spend only about 15 percent of the night in REM sleep. With the exception of infants, people spend most of the night in the light sleep phase. 

That said, REM is an incredibly important part of our sleep—and most of us aren’t getting enough of it in our sleep-deprived society. “If we’re trying to get away with sleeping less, we’re getting less REM sleep,” says Drerup, since REM sleep can get short by an alarm clock and a mad dash out of the house in the morning. While there is a general guideline that you should get seven to eight hours of sleep each night, Drerup says that opposed to getting the “right number,” people should focus on improving their quality of sleep first. That includes limiting environmental disruptions, identifying and treating sleep disorders, limiting blue-light exposure to phones and other devices at night, and making sure you’re getting enough activity during the day. 

The purpose of sleep stages

Each sleep phase serves a specific physiological purpose. The primary function of both our light-sleep and deep-sleep phases is to have a regenerative effect on various processes in the body. 

“We tend to think about sleep as a thing that occurs just at night, but it has consequences on your whole 24 hours,” says Drerup. “Things like your mood and your ability to focus and concentrate have been known for a long time, but now we have more evidence and research tying the lack of sleep to being associated with decreased immune functioning, Alzheimer’s and cardiovascular risk. So less sleep not only affects you that day but has long-term health consequences.”

During non-REM sleep, the body repairs itself, builds bone and muscle, and bolsters the immune system. As you get older, this non-REM sleep decreases significantly—from around two hours per night when you’re under 30 to possibly just 30 minutes when you’re over 65. And during both deep sleep and REM sleep, the brain works to process the impressions and memories of the day. For example, if you get an adequate amount of sleep the night before an exam, including several deep-sleep and REM phases, you’ll be better able to recall the material you’ve studied.

A review of research published in the journal Biology of Mood & Anxiety Disorders in 2015 also indicates that getting a sufficient amount of REM sleep prior to a traumatic or fear-inducing experience, as well as in the early stages of a trauma’s aftermath, may make a person less likely to develop PTSD. The bottom line: Sleep is incredibly important for a variety of reasons, some of which we’re still learning about. That’s why you won’t want to miss these easy ways to sleep better.



If you’re Self-Employed, You Might Be Making This Big Retirement Mistake


Self-employed Americans have a serious saving problem, according to a new study.

People who work for themselves are simply not stashing away enough cash for a comfortable retirement, a report from the Transamerica Center for Retirement Studies finds. Just over half (55%) say they consistently save for retirement and only 30% save from “time to time,” according to the online study, which surveyed almost 6,000 Americans, around 800 of whom identified as self-employed. Even more troubling? A full 15% never save at all.

The median household retirement savings for self-employed people is just $71,000, according to the study. Even if you don’t have access to a workplace 401(k) plan, you can still set up an Individual Retirement Account (IRA) and fund that. One reason for this savings shortfall is that people in business for themselves plan to keep working longer than people who work for someone else.

Being your own boss does offer you more flexibility in terms of when you retire, and could help you avoid the age discrimination that many older Americans contend with in the workplace. Yet believing you have complete control over your career is a mistake, one that may be causing business owners to under-save and under-insure themselves.

Almost 70% of self-employed people and 54% of traditionally employed people expect to retire after age 65 or not to retire at all. In reality, the median retirement age for workers is 62, according to the Employee Benefit Research Institute. Four out of ten Americans end up retiring earlier than expected due to issues often associated with aging: The most common reasons are having health problems or a disability (35%) or organizational changes at work like downsizing (35%), according to the Employee Benefit Research Institute. Thirteen percent of people also reported having to retire early to care for a spouse or other family member

The Transamerica study suggests that self-employed workers aren’t prepared for these risks: only 81% have health insurance, just 46% have life insurance, and a paltry 23% have disability insurance. Disability insurance protects you financially if an injury or health issue prevents you from working for an extended period of time. The earlier you apply, the better, since rates tend to rise with age. Policies typically pay out only until age 65 or age 67, so make sure you understand the limitations of yours.



3 Ways to Unleash Your Creativity

Clever tips for getting inspired, motivated, and prepared to maximize creativity.

Jason Fell

Creating something from nothing isn’t simple. Inspiration, perspective, motivation, and the right tools are all critical elements to creativity. Having the exact right combination of all of these things, at the perfect time, isn’t always easy to come by.

Good news: There are strategies we can employ to give our creative sensibilities a jolt and ensure that we’re prepared to build whatever our hearts—or jobs—tell us we have to do.

Consider the following tips for unleashing your inner creative brilliance:

1.To spark creativity, get moving.

Sitting at your desk in front of a screen all day isn’t usually the most effective setting for dreaming up big, clever ideas. One of the best ways to get the creative juices flowing is to get up and get moving.

Studies have shown that stepping away from your work and going for a walk stimulates the neurological and physiological pathways that lead to creative thinking and problem solving. Turns out, it’s a simple strategy employed by many of the world’s top innovators, visionaries, and creators. Sometimes you need to take a break and clear your mind to make space for good ideas.

2.Seek out new experiences.

To one degree or another, we’re all creatures of habit. But if you’re stuck in the same routines doing the same things over and over, it leaves little room for thinking differently.

The more and varied our inputs (the places we go, people we speak with, media we engage with, etc.) the more our outputs (creativity) can evolve. In other words, go take that vacation you’ve been dreaming about. Read books. Strike up a conversation with that neighbor or co-worker you’ve never spoken to before. If you have time, try learning a new language.

Studies have even suggested that playing video games can help people become more creative in their tasks and projects.

Inspiration can come from the most unlikely sources, so increasing your interactions will in turn increase your chances for coming up with something you’ve never imagined before.

3.When it’s time to work, mitigate distractions.

Most creatives strive for what’s called a flow state, known more commonly as “being in the zone.” It’s a period of intense thought and concentration when a creative is getting his or her work done—fully immersed in whatever project they’re working on.

To mitigate distractions while in the zone, start by turning off non-critical notifications on your phone and laptop. A constantly dinging phone doesn’t lend itself to getting highly creative work done. Try to find a quiet place away from similarly jarring sounds—avoid coffee shops, casual conversations, barking dogs, etc.

Then, do whatever sets you up for maximum creativity. Depending on the type of creative work you’re doing, researchers have said that some level of sound or noise can help boost creativity. When writing, for example, electronic or classical music can help hold you in that flow state.

Music with lyrics, however, can prove to be distracting.

Ideas only have value when they’re acted upon. To realize your full potential, set yourself up for that creative flow state from which the best ideas, and execution of those ideas, takes shape.