So often we hear about the importance of getting 7-8 hours of sleep each night. But, I’m sure you can remember feeling energized when you had less – and feeling wasted when you got more. The hours of sleep really only matter if you are getting the right type of sleep! And, that’s where the Sleep Cycle comes in.
What is a Sleep Cycle?
We sleep in chunks of time of approximately 90 minutes (called a sleep cycle). During each block of time our body slowly descends into a deep state of sleep (where our body does its job of repairing and rebuilding/healing the body) and then back up to an almost awake state where we dream (important for thinking, memory consolidation and more).
When you disrupt these sleep patterns in the middle of their usual cycle you lose out on valuable recovery which can really affect your next day’s energy level. Think back to a time when you were awoken in a deep sleep – such that you didn’t remember what day it was, where you were, etc. I’m guessing you had a tough time shaking off this groggy mood for the rest of the day! That groggy disorientation is called sleep inertia.
What Disrupts Sleep Cycles?
What can disrupt the cycle? Noise. Kids. Spouses that snore. Pets on the bed or in the bedroom (I’ve heard of cats that walk on their owner’s face). Certain medications. They can all mess with your sleep cycle. Caffeine can keep you up longer. And, while alcohol makes you feel sleepy, it also prevents you from sleeping deeply.
To get the best night’s sleep you can, avoid or control as many of the disruptions as you can. Obviously, it’s difficult to control if our kids wake us up early in their life…but could you limit the nighttime alcohol or use a sound soother to block out irregular noise?
So, How Many Hours of Sleep Should I Get?
Since, ideally, you want to wake during the dream stage (which is a light state of sleep)…at the end of a sleep cycle, plan on finishing each of the 90-minute sleep cycles. In other words, if you’re pressed for time and you’re sleep-deprived, it may feel better to sleep 6 hours, rather than 6.5 hours. Why? Since we sleep in 90-minute sleep cycles, you’re likely to be finishing a sleep cycle at 1.5, 3, 4.5, and after 6 hours of sleep. If you allow your body to go into the next sleep cycle, say at 6.5 hours of sleep, you could find yourself in that deep stage of sleep – and feeling groggy all day!
How can you find out more about your particular sleep cycle outside of getting a professional sleep study in a lab? Try downloading a sleep cycle app on your smart phone. Then set your phone on your nightstand so it can monitor the sounds you make. Your body is in a sort-of paralyzed state during deep sleep with more movement (and sounds) as you get into light sleep. The app will allow you to set a range of time for you to wake up. And, it wakes you when you’re in a lighter stage of sleep so you feel more refreshed.
Want to learn more about sleep? Check out SleepFoundation.org.