Sleep is a wonderful thing. Unless you are a 6-year-old kid, you love going to sleep and you probably hit the snooze button a few times before waking up. It’s what reenergizes you for the next day. Everyone loves to sleep there’s no doubt about it. And yet no one really knows what actually happens when you are asleep.
Do you just lay there with your mouth open drooling on the pillow? Or is your brain actually doing something productive while you sleep? Well of course we dream, but that can’t happen the entire time, our dreams seem way too short for that to be the case. Well, the body actually goes through 5 stages of sleep in the course of the night. In a cycle actually meaning it will go through 1, 2, 3, 4, 5, 1, 2, etc… Let’s take a look at the stages of sleep.
This is the lightest sleep stage and usually lasts for 5 to 10 minutes after falling asleep. You are able to be awakened without difficulty and you will feel as if you haven’t slept at all if you are awakened. The brain has slowed in activity at this point from a wakeful state and your muscles start to relax. This is also the stage of sleep where you may feel a falling sensation while lying in your bed.
This is another period of light sleeping. Your brain gives off larger positive and negative waves of activity which indicate your muscles relaxing and tensing up. You’re heart rate slows down in this stage and your body temperature decreases. Your body is getting ready to enter the deeper stages of sleep.
This is the first stage of deep sleep. Your brain starts sending out slow delta waves; however, there may still be short releases of beta waves from faster brain activity. If you are woken up at this stage of sleep you will likely feel very confused and groggy at first, perhaps unsure of why you passed out on your kitchen floor with a tub of ice cream laying right next to you.
At this point in your sleep your brain has slowed down to its lowest point and you are in the deepest part of your sleep. Your brain only gives off delta waves and it is extremely difficult to wake someone up at this stage of their sleep. In stage 4 people are susceptible to bedwetting, sleep terrors, and most notably sleepwalking. Stage 3 and 4 can last anywhere from 5 to 15 minutes but the first deep sleep of the cycle usually lasts about one hour. During this stage of sleep is when your body does the most recovery.
REM sleep, also stage 5, is the last stage of the sleep cycle. REM stands for Rapid Eye Movement. During REM sleep your brain activity and breathing rate increase. This stage is also known as the active sleep stage, your brain activity is most similar to when you are awake at this point. You dream in stage 5 REM sleep. Also, your muscles in your legs and arms will go through paralysis; this is thought to happen because nature doesn’t want us to act out our dreams. The first REM stage of the night occurs roughly 90 minutes after falling asleep and lasts about 10 minutes. As the night goes on, the time that REM sleep lasts grows longer with the last cycle of REM sleep lasting about an hour.
Not much is actually know about what happens specifically to our bodies during each stage of sleep. Studies and tests are being conducted, but it can be hard data to gather. As you can see, our brain is a very complex animal when it comes to sleeping. So the next time you wake up in the morning wondering what happened to the last 8 hours of your life, you will appreciate it a bit more than before.