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Brandon Peters, M.D.

Review: Popular iPhone App, 'Sleep Cycle', Tracks Movement to Time Awakenings

By December 30, 2011

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One of the most popular of the sleep-related apps (or applications) for iPhone, 'Sleep Cycle' works by tracking your movements during the night in order to perfectly time your morning awakening. What are the pros and cons of this app?

'Sleep Cycle' relies on your iPhone's accelerometer to monitor movement. The idea is that you place your iPhone near you in bed and that it will register movements. When you are in deeper sleep, especially REM sleep, it will document this stillness. When you are restless towards morning, drifting into lighter stages of sleep, it will seize on this wakefulness to alert you to get up for the day.

The interface of the app is slick. There are five tabs of controls and information. The first tab offers instructions on how best to place your phone and use the app. Under settings, you can choose an alarm sound (including a favorite song) and set your snooze options. You select a 30-minute period that you wish to awaken during. Then, each night after using it, it creates a summary page that includes a hypnogram (showing sleep stages) as well as your bedtime, wake time, and total and average sleep time. There are also options to share this information by email and Facebook.

'Sleep Cycle' is accurate at tracking the consistency of your sleep schedule. This is similar to documenting your sleep patterns with a sleep diary, and akin to monitoring that is better accomplished with an actigraph. But at a cost of just 99 cents, it is much less expensive than actigraphy.

There are unfortunately a lot of drawbacks to the 'Sleep Cycle' app:

  • In order to function, the program must run overnight and this will slowly drain your battery. Although it will no doubt vary with your battery's age, it drained mine by 20% over 8 hours. The instructions recommend that you keep your phone plugged in, which could present a choking hazard should you become wrapped in the cord.
  • The accelerometer will pick up any movements, including those of bed partners or pets.
  • It brings your phone into the bedroom, and unless you put the phone in flight mode, you will be bothered with calls, texts, and alerts throughout the night.
  • The sleep cycle hypnogram (for which the app is named) does not appear to be accurate. If you have a soft mattress pad or other bedding, the accuracy will suffer even more because movements will be missed.
  • Setting a 30-minute window in which to have my alarm go off often left me getting less sleep than I desired. I would pick the later time to be the time when I absolutely had to wake up. More often than not it would awaken me earlier, which left me with less sleep than I had desired. I never really felt that I awakened more refreshed because of the perfectly timed alarm clock.
  • In general, having the phone in bed also made me more conscious of being awake or asleep, and this seemed to fragment my sleep.

Therefore, though 'Sleep Cycle' is an exciting development in inexpensive technology that may help us to monitor our sleep, it seems that it is really only accurate to track your bedtime and wake time. It should not be used as an alternative to more sophisticated sleep studies. There are a lot of problems with its use, and I would not recommend it for these reasons.

What do you think? Share your favorite sleep apps.

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January 8, 2012 at 11:45 pm
(1) Cathy says:

I think this is a really great app to try! I am definitely giving it a shot. I have been trying to decide if I need a new mattress – if my really old (thirty years old) mattress is causing me to stir too much at night. I never feel rested when I wake up, and after what I found at http://www.qmattresses.com, it kind of makes sense that the problem might be my mattress. I will be sure to put my phone in airplane mode and charge it well before I go to bed to try it out though. Thanks for the helpful hints. :)

January 26, 2012 at 10:06 pm
(2) Tombo says:

Sleep Sounds is a good one too.

March 12, 2012 at 11:08 pm
(3) Kris says:

Brandon Peters, You’re article makes you seem to be a jaded individual, but that’s okay!

I will this App!

March 13, 2012 at 12:52 pm
(4) Paul says:

What a ridiculous list of drawbacks…

March 21, 2012 at 6:06 am
(5) H Brown says:

I concur that the author of this article projects a jaded tone, and that the list of drawbacks are ridiculous.

While I was reading the list of drawbacks I was wondering of it was leading into a gotcha type joke nope, the author sincerely believed the “drawbacks” to be serious.

April 4, 2012 at 8:45 am
(6) Gc says:

I just used the app for the first time last night. I have a memory foam mattress so I didn’t expect it to register much, but it appears that it recognized a lot of movement. Also, I managed to not get wrapped up in the cord while I slept. I have faith in all of you that you won’t accidentally die because of this app. Dream big, readers.

April 13, 2012 at 11:58 am
(7) Michelle says:

You are supposed to place the phone/iPod underneath the fitted sheet on your bed. That effectively solves the getting tangled up in the cord problem.

April 17, 2012 at 11:52 pm
(8) Dennis says:

There have been a lot of reports of people leaving their phones on their nightstand or desk overnight and getting the same graphs; i.e., the app is a fake. Have you tried this?

April 25, 2012 at 3:07 pm
(9) Teresa says:

I agree with Paul. My iPhone cord is about 2 ft long. I would have to be quite the active sleeper to be able to strangle myself with it.

June 9, 2012 at 3:00 am
(10) Sal says:

Hahaha as if the cord could possibly present a choking hazard, the kind of manoeuvre someone would have to do for this to occur is so outlandish. This really made me laugh.

C’mon people don’t hate on this writer, its not nice! Concentrate on the topic at hand instead of personally attacking a reviewer by calling him jaded etc. What’s with people today? Always taking chinks out of someone’s armour! :( It’s just mean!

July 23, 2012 at 11:10 am
(11) JM says:

I just used this app for the first time last night. I managed to avoid choking to death by putting the phone under a fitted sheet at the top corner of the bed per instructions. The accelerometer is very sensitive in my 4S. In the test it even picked up movement from my wife walking around the bed. And if it registers those same movements when it is analyzing sleep patterns it may be off occasionally. Overall it appears to be a cool app and sort of fun to try. I’m not sure how long I want to keep putting it in airplane mode and slipping it under the sheets.

August 8, 2012 at 10:44 pm
(12) John says:

After reading the author’s note about the phone’s cord being a choking hazard, I’ve been very concerned. In fact, I’ve been losing sleep over it. I’ve decided that, on my next day off, I’m going to rip all the cords and cables out of my house. Sure, it will make things pretty inconvenient, but is convenience worth taking a chance on walking down the hall, tripping over the vacuum cleaner cord, and strangling myself?

August 13, 2012 at 10:14 am
(13) DaveyWavey says:

30 year old mattress? *shiver*

August 20, 2012 at 11:42 am
(14) garfield Lee says:

John, i laughed hysterically for 10 minutes after reading your comments about removing cords from your home. Thank you, that made my month.

And if jaded is the worst shot that the good doctor is getting he is doing well.

August 23, 2012 at 10:09 pm
(15) John says:

Maybe you would wake up rested if you kept ur phone at ur neightbours house or in the cellar?

September 28, 2012 at 10:28 pm
(16) response to john says:

brilliant. still laughing. perfectly done at the end.

October 8, 2012 at 9:50 am
(17) Dan says:

I didn’t have any intention if leaving a comment, but after seeing that I wasn’t the only one who, literally, laughed out loud at the suggestion someone may choke themselves with the phone charging cable still has me chuckling as I write this. As someone else pointed out, it seems, even though it might be a pain in the butt, you are supposed to put it directly on the mattress and under the fitted sheet. I can imagine that would also help with sensitivity even though I did the test and it picked up on my movements far better than I thought it would.

October 9, 2012 at 11:16 am
(18) Josh says:

I have used the app for the past two nights, and it really has done a great job, despite the fact that some of the movement in the middle of the night WAS from me being strangled by the cord. This isn’t the phone’s fault though. I wrapped the cord around my neck prior to going to bed. I just wanted to see what would happen.

Good app!

October 31, 2012 at 10:21 am
(19) Auping Royal says:

I think this article makes a clear point about why this app is not working sufficiently. But nonetheless, it works fantastic for me. (placebo effect?)

November 1, 2012 at 11:35 pm
(20) caspers step bro says:

By not heeding your advice about the cord being a potential choking hazard…. I am now a ghost… I sleep all the time….thanks sleep app…Better than expected results!!

Yours truly,

Well rested poltergeist

November 13, 2012 at 4:01 am
(21) Me says:

Ok, the chord bit might have been stretching things a bit, but a lot of this is the same for me. Unless you sleep alone or with the living dead, everything your partner does, registers too. We tested this in a king size and though the phone is safely tucked in the far corner near my head, my partner’s movement register with the slightest movements. When I see the chart, I’m not sure how much of that is me. Also, the timing is a bit difficult to gauge. I need to get up at 5:05 not later and I certainly don’t want to be getting up too much earlier. That’s early enough. On the first night I was woken at around 4:35. I was not happy. Other days I’ve been waking at 15-20 mins earlier than desired. This is where it really falls down for me. If I had the leisure of waking whenever I feel like it, then perhaps this would wake me when I’m coming out of deep sleep and being more active, but in being woken even earlier than 5am, I miss out on sleep and I’m really feeling it. On the upside: nice tunes.

November 18, 2012 at 3:54 am
(22) Swampy pants says:

Luckily I did not become wrapped in the chord, although I did use it to strangle a hitchhiker with.

I notice this obvious danger was omitted from the review. I blame the author for not warning me about this clearly dangerous downside to the app and will be using this as my defence in court. Dangerous app, do not buy.

I may or may not have made that up.

On a separate note, please can somebody call the fire brigade as I am entangled in various bits of household appliances and other dangerous items.

December 22, 2012 at 11:38 am
(23) Steve says:

It’s true! I tried this app and despite my years of self control, I woke to find that I had chewed through my fitted sheet and was literally fighting my own hands to keep them from wrapping the cord around my neck. That wasn’t the worst part though, the next night I found myself fondling the phone’s “sound off” switch and holding it vibrating in strange places. I sure slept good after that though!

Seriously, the app works. Macrumors.com has an article on it. If you’ve ever downloaded the seismograph app for your phone, you know that the accelerometer is unbelievably sensitive. The phone picks up very subtle vibration and movement. The app does an amazing job of taking the limitations and making them a useful and reasonably accurate tool for implementing proven sleep science.

Now, back to my love affair with my phone…

January 9, 2013 at 1:19 pm
(24) John Doe says:

I’ve only used this app for two nights but so far it seems to be doing what it says. I joined the parade of laughs reading the good doctor’s cons for this app. I almost wrote off his whole article based on the choking hazard comment.

After reading a few articles and reviews of this app I understand the reason for needing 5 nights of sleep to calibrate the accelerometer to your sleep conditions. So yeah, if you live in/near a place with constant vibration or movement the calibration time takes that into account to register that as a baseline or “zero movement”, to include your spouse or pet.

As for the “wake window” the intent is to wake you during your lightest sleep so as to avoid the jump from deep sleep. The comments from “Me” above (Nov 13) make them sound like an idiot. If your “wake window” is 10 minutes, that’s a “you” problem. The reason it’s waking you up earlier is becaue the app is detecting you in a wake cycle. If you still feel crappy you’re probably not getting enough sleep. So go to bed sooner if you can. Likewise with the reviewer, if you NEED that extra 20 minutes of sleep you’re probably not getting enough sleep to begin with.

Lastly, there are probably bigger issues at play if sleeping with your phone in your bed causes you to be more conscious of the changed surroundings. IMHO

This seems to be a great app. I look forward to using it a whole lot more. BTW, works fine with iOS6 and iPhone5.

January 17, 2013 at 7:29 pm
(25) Piloga girl says:

Oddly enough, no one has commented on the fact that your phone is emitting all these waves right next to your head…?! Is that deemed safe? I find that the app works and it’s really cool, but I’m slowly beginning to wonder how smart it is that my iphone is right next to my head every night….. Hm

January 25, 2013 at 6:18 pm
(26) Andrew says:

Has anyone found it to be a hassle to have to pry up the corner of the fitted sheet to remove your phone and shut off the alarm? Sounds inconvenient to me, especially first thing in the morning (groggy) and in the dark.

February 1, 2013 at 5:44 pm
(27) Michelle says:

Never thought I would read so many reviews just for the
comedic value. Hilarious!!!

February 11, 2013 at 5:34 am
(28) Sleept like a log says:

Great App! working FIFO (Fly in Fly Out) Mine Construction and this app is helping me get the most out of sleep.

I have found that the app has helped me form a healthier routine, by setting my body clock to the correct wake time. Now my alarm wakes me within a 10 minute window rather than a 30 minute one.

I have no issues with placement or cords using this app with an iPad mini, yes that wasn’t a typo.

@John Doe: I think you are right that you need to give the app a week to gather the baseline and re adjust your pre-bedtime habits if you are wanting any form of success.

February 25, 2013 at 6:19 pm
(29) Anon says:

I accidentally knocked my phone off the bed, and the graphs showed movement. What’s up with that?

March 5, 2013 at 11:35 pm
(30) JC says:

I love this app, it’s really hard for me to wake up in the morning and this has made my mornings so much easier. I also feel better rested being woken up during a shallower sleep phase. And for anyone who managed to get past the cord strangling drawback ridiculousness and is sincerely holding back because he mentioned feeling like he was being woken up too early, in the settings you can adjust the window of time. It can be set to as low as a 10-minute window. I feel like this reviewer didn’t really do their homework before reviewing it, or even use it for more than a day. Awful review. Stellar app. Only costs a dollar, so even if you don’t like it I think it’s worth a try.

NOTE: The application has been updated since it was originally reviewed and that setting has been added. Thanks for your feedback. ~Dr. Peters

March 28, 2013 at 4:53 pm
(31) MichelleS says:

Tears in my eyes from laughing!…especially at the thought of Steve inadvertently gnarling through his bed sheets to get to the cord, that really was hilarious!

I have been using the app for a few days and find myself really keen each morning to see how I have slept, but getting disappointed with a ‘score’ of 65% and thinking, where did I go wrong?!! … I will continue to use it and try figuring out for myself what good will come of knowing this information

April 16, 2013 at 6:57 am
(32) Lcritter says:

Has anyone else noticed the sleep quality rating seeming inconsistent with the graph? Numerous awake times during the night is suppose to indicate a lower quality of sleep, however the night that this app shows I have a greater number of wake time also shows my quality of sleep at 95% and the nights that I have a consistent sleep or deep sleep time shows a lower quality of sleep. It might be accurate in the movement it detects but I question what criteria it uses to determine quality.

April 18, 2013 at 3:52 pm
(33) Fetter says:

Just wondering if it is dangerous to sleep with the iPhone under the pillow? Also if I use the flight mode. Does anybody know anything about this?

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