The Sleep Cycle: Do You Get Enough Undisturbed Sleep?

by Angela (Oh She Glows) on October 7, 2009

Good morning!

1 day until US Shipping! The Online Shopping Cart will be activated Thursday at 9am EST. I will be providing a link from OSG and Glo Bakery websites at 9am sharp.

It’s funny because this week I have been swamped with Canadian orders!


I guess the Canadians want to beat the US rush! Smart thinking! ;)

Be sure to check out the Shopping Cart + Shipping FAQ for the answers to all of your pressing questions!

  • Please take special note of item 15 on the FAQ page. Keep in mind that quantities on the shopping cart will be limited to start off with. I am going to make available the amount of bars that I can make in a 2 week period. I want to ensure that I maintain excellent customer service which is why I have decided to control how many orders I will be getting all at once. Please don’t despair if you do not get an order in on Thursday! I will be updating the quantities on the shopping cart as I bake new batches.


How Do You Sleep?

Speaking of losing sleep, I thought it would be timely to do a post on The Sleep Cycle from my book The Owner’s Manual For The Brain.

First, here are a few fun facts about sleep:

  • The average person gets 7.5 hours sleep
  • Infants get on average 14 hours sleep
  • Seniors get on average 6 hours sleep
  • Before the invention of electric lights, humans slept for 9 hours on average
  • When all cues to time of day are removed (pitch black), humans sleep about 10.3 hours

How do you measure up to these stats?

Personally, when I don’t have my alarm set, I naturally wake up after 8-9 hours of sleep.

The Sleep Cycle is KEY!

  • However, it is not the length of sleep that we get that causes us to be refreshed. It is actually the amount of complete sleep-wake cycles that we get!

Each sleep cycle has 5 phases:


[Image source]


The average cycle is 1 hour and 30 minutes, however cycle length can vary from 60-120 mins. depending on the person.

If we truly were to sleep without any disturbances and no alarm clocks, we would always wake up on a multiple of 90 minutes. For example after: 4.5 hours, 6 hours, or 9 hours of sleep.

E.g., 5 complete sleep cycles = 90 mins + 90 mins. + 90 mins. + 90 mins + 90 mins = 7.5 hours of sleep.

Non-REM sleep lasts about 70 minutes per cycle, while REM sleep lasts about 20 minutes per cycle. REM sleep is when we DREAM!

Here is the kicker:

A person who only gets 4 cycles of undisturbed sleep (6 hours) will actually be much more rested than a person who has slept for 8-10 hours but who has not been allowed to complete any one cycle because of being awakened before it was completed.

This is why many top sleep doctors advise people not to sleep with pets in the bed, because often pets disturb your sleep several times during the night and you feel very tired the next day and not know why.

I wish Eric and I could follow this advice! ;) Sketchie happily sleeps at Eric’s feet every single night and we wouldn’t have it any other way.

Want to wake up easier? Don’t wake up in REM sleep!

The time between our REM sleep (stage 5) and Stage 2 is called the Twilight Zone (Stage 1). The Twilight Zone is the brief period in between each 90 min. sleep cycle. If you are in Stage 1 of sleep, it is very easy to wake up. You will find that any light stimulus will wake you from a light noise to the sun rising.

Waking up in the second half of your sleep cycle (especially during REM sleep) is often very difficult. Many people report not being able to wake up.

Get this: When we are in REM sleep, our motor output system from the brain is completely shut down (this is why we dream that we are running but we don’t actually run) and also explains why we feel so lifeless when we wake up during REM sleep! Now of course, the motor output system doesn’t always turn off, and we see this especially with sleepwalkers. That is another topic though!

This morning, I woke up in the middle of a dream (REM sleep) and I felt like I was hit by a truck when my alarm went off (even though I had technically the proper ‘length’ of sleep!). I couldn’t wake up for a good hour and walked around like a zombie.

However, if you wake up in the beginning stages of sleep (especially the Twilight Zone), you will find that you wake up easier and feel so refreshed when you get up. I often wonder why some mornings it is so easy to wake up and others it is a battle. This explains a lot!

So fun things to try out:

  1. Keep a Sleep Journal.

Record the beginning and waking times for each natural sleep episode that is uninterrupted by an alarm or other disturbance. Find the common multiple. For example, if your recorded sleep periods were 400, 500, 400, 200, and 700 minutes, you would conclude that your personal sleep cycle typically lasts 100 minutes, or 1.6 hours. If you don’t want to keep a journal, just assume it is 90 minutes in length.

2.    Plan your waking accordingly

For example, if my cycle is 90 minutes and I fall asleep at midnight every night, I should plan to wake at any of the following times: 6am, 7:30am, or 9am. All three of these times are multiples of 90 minutes. I would technically be waking up after a full sleep cycle, ideally. If I got up at 8:30am, I would be getting up in the later stages of sleep and would probably find it more difficult to wake up. Apparently there are devices that you can buy to simplify the process.

This morning, I naturally woke up in the Twilight Zone. I felt awake and ready to get up, but since it was earlier than I needed to get up I allowed myself to fall back to sleep for another 45 minutes. Well, when I woke up 45 minutes later it was almost impossible to wake up (I woke up in the middle of a dream). That’ll teach me! ;)

3.   Visualize Waking Up 

In an interesting study published in Sleep in 1997, participants were asked to visualize their time of waking on an imaginary clock face. Results found that those who visualized what time they had to get up were naturally able to wake up at the desired time without any alarm (this is SO me!). The key techniques: Get the same amount of sleep nightly, visualize the time you want to wake up, and use a back up (a clock set 10 minutes later than your desired time).


What are you sleep-wake patterns like? Do you think you get enough undisturbed sleep?


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{ 70 comments… read them below or add one }

Allegra October 7, 2009 at 8:38 am

Sleep most definitely depends on stress and what day of the week it is. As a live-in professional at a major university, there are nights that I have to accept that I won’t get any sleep until 2 or 3 in the morning! However, it does make me appreciate the nights I get really restful, deep sleep! :-)


Angela (Oh She Glows) October 7, 2009 at 8:55 am

Oh wow I can imagine…weekends must be noisy and whatnot!


Melanie October 7, 2009 at 8:40 am

Hey…does Sketchie bother you guys in the night, though? Or does he stay at Eric’s feet all night. Shelli has to sleep right next to me (actually, she likes to “spoon”…weird, eh), but she’s really bad about getting up and moving around. And whenever I get up in the night to potty, she’s on the go after that. I reallyreally don’t want to exile her to another room, though, b/c I absolutely love that she wants to be close to us. Do you deal with that with Sketchie too?


Angela (Oh She Glows) October 7, 2009 at 8:56 am

Well, Sketchie used to sleep on my side, but I made him switch over to Eric’s because he was disturbing my sleep so much. Eric says he doesnt bother him though (he is a deep sleeper whereas I am a light sleeper). It works much better this way. I still think that Sketchie wakes him up during the night though…he just doesn’t want to admit it! lol


Diana October 7, 2009 at 8:41 am

Wow, this is so interesting! And explains a lot, actually. I remember talking about this in school but we didn’t go very deep into the subject.


Pam October 7, 2009 at 8:42 am

I would like to have more undisturbed sleep, that would be nice. Hot flashes…I do know that when I don’t eat a lot of cooked food I don’t have as many!

Great post!


maria October 7, 2009 at 8:47 am

Thank you for the sleep advice. I learned a lot of this during my high school psychology course, but it was a great refresher (hah!).


rhodeygirl October 7, 2009 at 8:53 am

random question: are you going to the foodbuzz festival? as a vendor? they are having an afternoon of tastings of different products and foods. you should definitely come and showcase your new stuff!


Angela (Oh She Glows) October 7, 2009 at 8:57 am

I would love to, but I just don’t have the funds to get there. For me to come from Canada it was be over $1,000 for air and hotel!!!! Too bad, cuz I would LOVE to attend!


Angela (Oh She Glows) October 7, 2009 at 8:57 am

*It would be I meant :)


Julie October 7, 2009 at 11:07 am

hey everybody lets raise $$$ for angela to come to the US to showcase her new goods! =)hehe


Alyne June 7, 2010 at 11:41 pm

you should couchsurf while you’re there. free board!

it’s amazing. you meet amazing people and save amazing money and learn amazing things.
it’s almost too MUCH amazing <333


Sarah @ The Foodie Diaries October 7, 2009 at 8:56 am

Gracias for this, Angela! I have terrrible problems sleeping so I found this really interesting. I almost NEVER dream–and now I wonder if that have something to do with my REM cycle.

I also completely agree with the visualization technique; that actually has worked for me in the past. I think we’ve become really reliant on prescrip. meds as the general response to sleeping problems–but I think that cognitive behavioral therapy is much more effective (especially down the road!).

Have a great Wednesday!


nic October 7, 2009 at 8:58 am

That is really interesting!! I though it had to be something like that because often I feel very tired after 8-9 hours of sleep, know I can understan why!! It happens from time to time that I wake up a little before my alarm goes off and I feel really awake BUT go back to sleep just because I know I can and when the alarm finally goes off I almost can’t get out of my bed!! Ugh… I will definitely sit down and calculate a little and see how it goes!!
Thank you for this post!!! Have a great day!! Hug n.


Shannon (The Daily Balance) October 7, 2009 at 9:04 am

Thanks for this post — interesting stuff that you forget to actually *think* about!


Jolene October 7, 2009 at 9:05 am

I think I wake up during a dream everyday during the work week – it is always so hard for me to get up, even though I got an adequate number of hours of sleep. On the weekends, I wake up naturally no problem – and relatively early as well.


Colleen October 7, 2009 at 9:20 am

I’m such a sleep-walker, sleep-talker. During stressful times I often have night terrors, which is probably scarier for my husband than for me (he usually just turns on the light and I wake up).

Every morning my alarm goes off and I’m dreaming, and of course I feel like I’ve been drugged. This post is so helpful! I’m really going to re-evaluate my sleeping and try to come up with a better schedule. Thanks Angela!


Jessica @ How Sweet It Is October 7, 2009 at 9:25 am

So excited for US shipping! Woohoo! :)


Madeline @ Greens and Jeans October 7, 2009 at 9:27 am

I used to be a TERRIBLE sleeper! I had stress induced insomnia and I would only get a couple of hours of sleep at night. I worked with a yoga instructor on ways to clear my mind and relax and BOOM! I was sleeping like a baby. 4 years later, I still get at least 7 quality hours of sleep every night!


Marissa (Where I Need to Be) October 7, 2009 at 9:29 am

I can sleep anytime, anywhere … I am blessed :)


Angela (Oh She Glows) October 7, 2009 at 10:33 am

Sounds like Eric…hahah


Nikki T October 7, 2009 at 12:16 pm

Me too! My husband gets so jealous…


Lizzy October 7, 2009 at 9:33 am

i never seem to get enough sleep! this post is great. i need to reread for sure because there is so much info that i want to take in! thanks girl!


Mellissa October 7, 2009 at 9:36 am

I am a horrible sleeper, I toss and turn and never get enough sleep! I wish I was better.


Emily October 7, 2009 at 9:39 am

coming from someone how is ALWAYS sleepy, thanks for this post!

Angela, I am really liking your new approach to your blog’s content. Having fewer yet more in depth posts are a treat to read, and I don’t have feel like I need to check multiple times a day. good work!


Angela (Oh She Glows) October 7, 2009 at 10:33 am

Thanks Emily :) I think it is working out for me as well. Better content, less rush, more quality. That is my goal.


Nikki T October 7, 2009 at 12:18 pm

I still find myself checking for new stuff often, but thats just ’cause I love the blog do much! :)
I definately agree with Quality over Quantity and you’re doing a wonderful job of it!


Nikki T October 7, 2009 at 12:19 pm

*so much, not ‘do much’!


Whitney @ Lettuce Love October 7, 2009 at 9:40 am

What a great post and so fitting since last night I randomly woke up at 3am. I am usually a pretty good 7 hour sleeper but every once and a while I will wake up for no reason in the middle of the night. I hear you on the dog in bed issue. When I visit my parents I sneak their dog, Laverne, into my room so she can sleep with me. She kicks and moves all night but I wouldn’t have it any other way. I don’t see her often so I don’t mind it.


Tay October 7, 2009 at 9:52 am

This is SUPER interesting. Must be why it’s soooo difficult to wake up early after only 4 hours of sleep or so! haha. I usually get undisturbed sleep, but for some reason always have 1-2 nights of tossing and turning a week. don’t know why!


Angela (Oh She Glows) October 7, 2009 at 10:32 am

too much coffee?? That does it to me (well green tea!)


Morgan @ Life After Bagels October 7, 2009 at 10:14 am

I got too much undisturbed sleep last night, I turned my alarm off and went back to bed for 3 hours, oh man . . . but I guess my body needed it!


Courtney October 7, 2009 at 10:21 am

I usually have no problems sleeping. However, every so often one little pointy footed dog will decide to stomp over the top of me in the middle of the night and that wakes me up!

Adventures in Tri-ing


Jessie (Vegan-minded) October 7, 2009 at 10:23 am

This is interesting. I know I don’t get enough undisturbed sleep, but I blame it on my cat. I am a very light sleeper, so my cat sometimes wakes me up by scratching at the window at insects that are outside, or jumping up on my dresser and knocking things down. He is annoying, but I love him too much to keep him out of my bedroom at night. He starts off every night by sleeping at my feet, but then he wakes and the mischief begins. Sometimes I sleep through it though. The things we do for our pets!


Janna from Just Flourishing October 7, 2009 at 10:24 am

Wow, so interesting!

I always wondered why some morning it feels nearly impossible to wake up!


Danielle C. October 7, 2009 at 10:24 am

Great post, I learned so much….I definitely agree on the last part about the timing of your wake up. Sunday night I slept over 9 hours and woke up feeling like I got hit by a bus…but I KNOW my alarm went off in the middle of a dream.

Our kitty used to sleep with us every night (for 5 years), lately he stopped (after we took him to get his teeth cleaned, maybe he’s still mad at us). I miss it so much! :)


SnowKat October 7, 2009 at 10:43 am

Hi Angela :) Great post !

As I sit here typing, I am in that zombie like state you described…. And it’s totally my fault. lol I have a cat and she knows that when I get up, she gets breakfast. My husband and I have recently started getting up about 2 hours earlier each morning because of his new job and our cat has figured out she can walk on us, nudge with her head and lick up to death until we admit defeat and get her her ‘breakfast’ even when its much earlier than we want to be up. AHHHHH We have created a monster! This morning the bumping and nudging began about an hour before our 6:30am alarm HAHAHAHA *sigh* The silly thing is, I am a behavioral psych major and I know how to fix this, but I have a hard time making her wait until later to feed her (set a schedule: 8am and then at 5pm for feeding) but it’s hard to not give in when she’s crying and crying (she’s 1/2 Siamese) Sorry for going on and on ;P …guess your post really spoke to me as I was drinking my 2nd cup of joe to try and shake the zombie like state I woke up in… haha

PS I voted for you on FoodBuzz!! Good luck!!!! You deserve it :D


Angela (Oh She Glows) October 7, 2009 at 12:13 pm

hahahah…oh man!!!! The things we do for pets eh?

Thanks for your vote!!!


Alisa - Frugal Foodie October 7, 2009 at 10:57 am

My husband and I turned off our alarm 10 years ago and have been much better rested for it. We used some vacation time from work to allow our biological clocks to kick in, so we were even able to go alarm-free when working for someone else. Of course, now we just roll out of bed into our home offices which is nice :)

We couldn’t keep the cat off our bed if we tried!


Leah @ L4L October 7, 2009 at 10:58 am

I get about 9 hours when I just wake up on my own. 10pm-7am is pretty much perfection. Unfortunately, that isn’t how the cookie crumbles during the week. It’s more like 9:30-10:30 (depending on if I have class) and up at 5am!


Cynthia (It All Changes) October 7, 2009 at 11:16 am

I try to get 7 hours a day. But that’s not uninterrupted. I usually get up at least once to go to the bathroom. I do feel rested though usually.


Oxidaisy October 7, 2009 at 11:20 am

Same cat issues here…except that we have 2…But it’s okay, one sleeps in the very corner of my half, the other one on top of my boyfriend.
What you wrote about feeling refreshed when you wake up in the first part of the sleep cycle totally makes sense. That is also why powernaps work so good! You do get the rest of being in the first cycle, but you won’t feel like a zombie when you have to wake up after max 20 minutes.


Anne Marie @ New Weigh of Life October 7, 2009 at 11:34 am

It’s so amazing-I’m just learning about the REM cycles in my psych class!


Beth @ DiningAndDishing October 7, 2009 at 11:40 am

Interesting!! Sadly I live downtown, right next to a hospital, so I hear very loud sirens all night! I have a fan in my room to create some white noise, but sometimes I still get woken up! Boo.


Angela (Oh She Glows) October 7, 2009 at 12:11 pm

I have to sleep with a fan too!


[email protected] October 7, 2009 at 11:52 am

Love all the “sleep” information, thank you!

It is funny because I have been wanting to start getting up earlier……6am……to start running in the morning (once the time changes that is as it is too dark to do it now) and I was a bit worried about not getting enough sleep!

No More! I would get at least 7 hours (6 hours of good sleep) so that is enough for me. =)

My husband always sleeps “6” strong, out cold, hours and is always up and ready to go after so that fact is SO TRUE.

=) Laura @ Finding A Healthy Balance (after “100 Pound” weight loss)


Mary October 7, 2009 at 12:13 pm

Thank you for posting this!! You have really encouraged me to tackle this, which is a major road block right now in my overall health. I love the kicking pets out, but it’s hard, that’s when my shy cat gets cuddle time, and knowing when to set up your wake time by sleep cycle is a golden tip, I will be following this–one of my posts last week was on sleep and I have failed to hit the early bed time I wanted. Thanks Angela!!


Jessica October 7, 2009 at 12:14 pm

Thanks for this. The alarm went off this morning while I was in the middle of a crazy dream about the Duggar family. I felt like a zombie which made no sense considering I’d logged enough hours in bed. I’ll give your tips a try and see if I can find that sleepy balance.


Laura @ Backstage Pass to Health & Happiness October 7, 2009 at 12:20 pm

Great article, Ange! This topic is very interesting.


Erin October 7, 2009 at 12:26 pm

I always wake up in the middle of crazy dream sleep – and the dreams are SO weird! I have actually been trying to fix my “clock” for the past few weeks so it will definitely be an experiment to start doing!


Lizzie October 7, 2009 at 12:36 pm

Apparently when I was little my parents would take me to see various friends and when it came time for me to go to bed, they would just put me behind a couch and I would go right to sleep! People would always ask if they would like to use a bed or a cot, and they would always be appreciative but said I could sleep anywhere!! I remember pretty much all my dreams – which is both good and bad! The former owner of our new place left behind his darkening shades (he was a medical resident at the time and so on shift work) and they have been awesome. Sleep SO much better than our last place. The only times I don’t sleep well are if I have to be somewhere very early in the morning and can’t be late. I keep waking up 2-3 times in the night thinking I’ve overslept!


Jenna (WholeBodyLove) October 7, 2009 at 12:47 pm

I rarely get more than 5 hours. Most weekdays I get about 4 due to all of the things that I have to fit into a day: work, class, taking care of Snuffy, studying.


leslie October 7, 2009 at 12:51 pm

that’s fascinating about the way you can track sleep cycles – i want to try that out! it’s also interesting that people sleep more in pitch black – my bedroom actually has no windows, and when i first moved in, i could not wake up for the life of me. i had been used to naturally waking up around 6, and i remember one saturday being shocked to wake up at 9. light is definitely a factor!

thanks for always presenting such varied, well-researched information. this was a great post!


Kristie Lynn October 7, 2009 at 12:54 pm

We let our cat sleep with us, too. She always likes to spoon next to me (yep, another spooning cat) – I only feel bad because it makes my husband jealous that she picks me over him! But I definitely wake up a few times a night from her moving around – usually every hour or so from 3am on. I don’t mind it enough to kick her off the bed though!

I’m definitely going to do some sleep-tracking… if I don’t workout in the morning I never will, and with work at 8:15 I have been getting up so early and if I wake up feeling refreshed it makes such a huge difference in how I feel the whole day.


Paige @ Running Around Normal October 7, 2009 at 1:11 pm

How interesting! All of it’s interesting, but in particular, the whole waking up on a 90 minute cycle thing.

Can’t wait for US shipping! Although I kind of feel bad for you :( I hope you don’t get exhausted. Don’t do more than you can handle. I’m sure everyone will understand if they don’t get their orders in a snap to begin with :)


natalie October 7, 2009 at 1:16 pm

I get a pretty good night sleep. About 8 hours. I used to wake up in the middle and have to go to the bathroom but thankfully that stopped!! If we let our kitty sleep with us I’d get NO SLEEP! She is constantly purring and licking our hair and moving back and forth..we did it this weekend and it was a nightmare!! :) good luck with everything tomorrow. hope it goes smooth!!


K October 7, 2009 at 1:17 pm

Wow, that book seems like a real treasure trove of information! Lots of interesting information in this post.
My dad is totally one of those visualizing people. He just thinks about the time he wants to wake up and presto! No alarm clock.


leatitia October 7, 2009 at 1:19 pm

I love the bits about the motor system being down, totally makes sense now!


jeri October 7, 2009 at 2:08 pm

I’m very fascinated by sleep cycles etc. Based on times that I’ve monitored waking up and feeling rested vs. when I fell asleep, I had determined that I had a 45 min. REM cycle, but it looks like, based on this info., that would be possible. Maybe it is actually 90 minutes. I might have to do some more researching. sleep = research. Doesn’t get better. :)


Eve October 7, 2009 at 5:16 pm

Wow, thanks for posting this info – this is great timing for me, as I am literally just trying to figure out how much sleep I actually need – I’ve always though about 9 hours, but the last few days I’ve woke up fine after 6 hours, and had more energy than I usually do. Buuut, yesterday I fell asleep in the middle of the afternoon – and I NEVER nap, so I guess I haven’t quite figured it out yet! :)


Susan October 7, 2009 at 5:30 pm

This is SUCH an interesting post!! I’ve been struggling with sleep a lot lately. I used to be able to fall asleep at any hour and naturally wake up 9 hours later. But now I have to be really rigid about my bedtime or else I don’t get enough sleep. Now I feel refreshed after 7 hours… but maybe I should bump it up to 7.5! ;)


Tina October 7, 2009 at 8:19 pm

That was so interesting! My sleep is so interrupted unfortunately. I’m not even sure why. But those cycles make sense. On average I wake up 2 or 3 times at least through the night. I definitely never sleep all the way through the night. I think it’s so interesting how we would sleep so much longer in a pitch black room though.


Anne P October 7, 2009 at 9:21 pm

I find this stuff absolutely fascinating. Great post! That definitely makes sense why some days I wake up ready to rock, when others I’m like, kill me.


Kath October 7, 2009 at 9:29 pm

Great post Ange! So interesting.


Caroline October 8, 2009 at 11:30 am

Interesting! Maybe I’ll try getting up at 5:30 instead of 6 next week and see if its any easier.


Jess October 14, 2009 at 12:40 am

I’m just getting around to reading this post and can’t wait to experiment with it. I have been sleeping MUCH better this last week – I think it’s cause hubby isn’t around and I don’t have to listen to him snore! Plus, I’m usually the one who can sleep for 12 hours and STILL want more sleep.

Our cats sleep on our bed too and, while they do wake me every once in a while, usually they don’t bother me. I don’t think I’ll ever be able to kick them out – I just love waking up in the morning with them snuggled around me. :)


sleep walker September 15, 2015 at 10:21 am

Interesting read thank you! I want to clarify for you’re readers that sleep walking occurs during non rem sleep cycles 4-5.


sleep walker September 15, 2015 at 10:22 am



sleep walker September 15, 2015 at 10:25 am

My apologies! Auto correct on my phone….sleep walking occurs during stages 3-4 non rem sleep


dana September 6, 2016 at 6:28 am

don’t think I’ll ever be able to kick them out – I just love waking up in the morning with them snuggled around


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