A Closer Look At Stage 2 Sleep & Why It's Essential For Waking Up Rested
As we sleep, we cycle through four sleep stages, each with its own function and purpose for helping the brain and body recover from the day. In REM sleep, for example, we dream, and in slow-wave sleep (or stage 3), we get the deep sleep needed for real rest. In the case of stage 2 sleep, it's where we spend about 50% of the night. Here's what happens in this stage, what it does for the body, and how to make sure you're getting enough.
What happens during stage 2 sleep?
According to neuroscientist and author of Biohack Your Brain Kristen Willeumier, Ph.D., stage 2 is a deeper sleep than stage 1, or light sleep, but not as deep as slow-wave sleep. It can last anywhere between 10 and 25 minutes during the first sleep cycle of the night, with each stage getting longer through the night. (We go in and out of stage 2 through the night as we cycle between the stages.) Within this stage, here are some of the things that happen:
- Body temperature starts to decrease.
- Heart rate and blood pressure decrease.
- Breathing rate decreases.
- Muscles relax.
- The brain begins producing "sleep spindles," or rapid bursts of brain activity that regulate sleep.
What is the purpose of stage 2 sleep?
Because stage 2 lies between light and slow-wave sleep, one of its primary functions is preparing the body to get into deep sleep. As Willeumier explains to mbg, it's easy to wake up during stage 1, but stage 2 is deeper. You'll become less responsive to external stimuli, like noise, as the body and brain settle in before deep sleep. "Your brain waves are shifting from beta to delta," she says, "and as you're entering into that slower brain-wave state, you're not going to be able to wake up as easily."
It's also when the consolidation of memories begins, she notes. "We know from a brain health perspective the consolidation of everything we've learned during the day in our short-term memory goes into long-term memory, and that begins during stage 2 sleep and continues on through stage 3."
How to know if you're getting enough.
The body will naturally cycle through stage 2 before deep sleep, so one of the best ways to know if you got enough of it is to simply assess how you feel in the morning. However, Willeumier notes, "It's difficult to say unless you're going for a sleep study," and even some sleep trackers aren't always reliable.
Essentially, if someone's getting a full night of quality sleep, they had to go through stage 2 to get there. And if you're waking up a lot throughout the night, or wake up feeling tired, it could indicate you're not getting enough of stage 2.
The caveat is, it could also indicate you're not getting enough REM or slow-wave sleep. Long story short, the only way to know for sure you're getting enough stage 2 sleep specifically, Willeumier says, would be in a lab. But generally speaking, it comes back to overall sleep quality and good sleep hygiene.
How to get more stage 2 sleep:
And speaking of good sleep hygiene, that's the best way to ensure you're getting enough stage 2—as well as REM and slow-wave sleep. All of them are essential to wake up feeling rested, and Willeumier has a few tried-and-true recommendations for getting enough:
Have a solid bedtime routine.
Perhaps you like to go for a bedtime meditation or take a relaxing Epsom salt bath. Whatever your bedtime routine consists of, a few rules of thumb to go by include going to bed (and waking up) at the same time every day, avoiding alcohol and food in the hours before bed, and dimming the lights around an hour before bed.
Try a magnesium supplement.
Willeumier is a big fan of magnesium as a sleep aid, and mindbodygreen's sleep support+ formula is magnesium-based. Plus, it has pharmaGABA (another favorite of Willeumier's).
Magnesium is an "essential mineral needed to help calm the body down," Willeumier previously told mbg, and it works to calm the mind, too. She recommends taking it about half an hour before bedtime for the best results, to help you fall asleep faster, stay asleep through the night, and, of course, wake up feeling rested.*
Make sure your room is the optimal temperature for sleep.
And lastly, make sure the temperature of your bedroom is somewhere between 60 and 67 degrees Fahrenheit. This is the best temperature for sleep, according to Willeumier, because a lower temp is "typically what helps initiate sleep—and that starts to happen during that stage 2 phase," she notes.
The bottom line is, all the stages of sleep are important, and stage 2 is essential for helping us cycle in and out of deep sleep and REM sleep, as well as consolidating memories. By practicing the fundamentals of sleep hygiene, we can help ensure we're getting enough of each stage so we wake up feeling rested and ready for the day.
Sarah Regan is a Spirituality & Relationships Writer, as well as a registered yoga instructor. She received her bachelor's in broadcasting and mass communication from SUNY Oswego, and lives in Buffalo, New York.