Getting a good night's sleep is elusive for many of us. We wake up tired, groggy or just feeling like we haven't gotten a good night's sleep. What happens when you head off into the land of nod? For many of us, it seems like we close our eyes and the next thing we know, we are woken up by the blaring sound of the alarm clock. For others, we toss and turn, stare at the glowing numbers on the clock throughout the night hoping for time to pass. Understanding sleep cycles, when they occur, and how they make you feel will help you understand your mood as you start a new day.

Traditionally, researchers have thought about sleep in stages. We all cycle in and out of these stages during the night. These stages include a period of wakefulness, light sleep, deep sleep, and REM sleep. In each of these stages, your body receives different benefits. Throughout the night, your body may cycle in and out these stages of sleep up to five or six times per night with each of these cycles lasting up to 90 minutes. However, each of these cycles of sleep does not look the same, nor do they last for the same amount of time.  

Stage 1: Wakefulness

This period usually occurs in between sleep cycles or at the beginning of the night as you are trying to fall asleep. Some of these periods are very short, so they are not memorable at all. This time is critical in that it allows our bodies to relax. In Stage 1, our muscles begin to let go, and our breathing starts to slow down. Some people say that they occasionally experience a sensation of falling or feel their muscles jerk during this time as their body begins to enter what almost feels like paralysis.

This stage usually lasts anywhere from 5 to 15 minutes at the beginning of the evening but can be just moments during the evening as your body re-enters another sleep cycle. If you are one of the unlucky ones, you may enter into a period of alert wakefulness during the night. It is when you stare at the alarm clock at 3:00 am. But for many of us, we do not remember this time.

Stage 2: Light Sleep

Stage 3: Deep Sleep

This stage of sleep is called deep sleep or slow wave sleep and produces slow, wave-like patterns your brain makes as researchers study rest. If you wake up during this stage of sleep, you usually feel foggy and may find it difficult to move your limbs. It is because your body has entered a phase where it is "recovering" from the day. Research has shown that the more activity, both physical and mental, that you do during the day, the longer you are likely to stay in this stage of sleep. This stage of sleep is most pronounced during the early stages of the night as your body relaxes and prepares itself for the night.

Stage 4: REM Sleep

REM sleep is the time where your body begins to come out of the deep sleep stage. It creates rapid eye movement, an increased heart, and breathing rate. You may spend anywhere from 10 minutes to an hour in this stage as your body finds itself between deep sleep and wakefulness. It is also the stage of sleep where dreaming, or nightmares, occur.  It is thought to be important for memory too. It isn't uncommon for the length of REM sleep to increase as the night progresses.

How Do I Know If I Am Getting Good Sleep?

A typical night's sleep will find you moving fluidly in and out these stages of sleep. However, we tend to spend most of our time in Light and Deep Sleep where our minds and bodies use the time to recover from the day's activities. If you have a device like a Fitbit or Apple Watch, you can loosely track your body's ability to move in and out of different stages of sleep during the night. These trackers use the movement of your body, heart rate, and other factors to approximate stages of sleep.

However, the best method is tried and true. How do you feel when you wake up in the morning? If you are still groggy, you may have woken during a period of REM sleep. Take the time to examine your sleep routines, including consistency when going to bed, waking up and your bedtime surroundings.

Can My Mattress Be Causing My Poor Sleep?

Just like many other factors including alcohol, room temperature, erratic sleep schedules and eating patterns, a poor mattress could be causing your poor sleep. In a study conducted at the National Institute of Health in 2015, researchers looked at the effect that mattresses had on elderly participants with regards to sleep and back pain. They found that mattresses affected both: a more comfortable bed and presumably reduced pain allowed participants to fall asleep faster.