Why is it that when we oversleep, we actually wake up feeling tired and can roll over and go back to sleep? It seems to me that after 12 hours or so, the body would say that is enough instead of let’s do it some more.
I asked this question last year, but don’t recall getting a definitive answer (perhaps there isn’t one.) I’ll see if I can dig up the link once the search limit has expired.
If you have slept that long, think about this: ** How long was it since you last ate?**
The inherent problem is that your glucose level is in the toilet after more than 12 hours of not eating. Low blood sugar = feeling/acting comatose if it gets very low. You need to be mentally motivated to eat something light and preferably with some sugar to get your levels up.
Here is my old thread.
I don’t know about the blood sugar theory. I regularly go without breakfast and don’t get sleepy. If I go until 3 or 4 pm without eating, Mrs Cad says I get crabby - but never sleepy.
If it’s not a blood sugar thing, how about dehydration? I know that drinking something with caffeine helps get me going in the morning, but I don’t know how much of that is the caffeine and how much is the drinking something.
That explains why I functioned so well when I was working early morning shifts and sleeping only 5-6 hours a night (had to get up at 3:00 AM, but hey - the ballgame isn’t over until 10:00 PM) — I’d pop out of bed ready to go when the alarm went off. But once I went to mostly night shifts and started getting a full 8 hours of sleep, it got harder to drag myself out of bed every day.
Maybe diabetes kicks the sleepy-on-waking=low-sugar equation into a cocked hat, but my sugar is never super low after oversleeping. More likely too high. But I feel sleepy all the same. I’m type 2, FWTW.
Inactivity and undernourishment work to keep blood sugar levels low and/or the body reacts by keeping insulin levels and other levels so that sugars are not ready to be used when they are available.
Activity begets activity. Get moving and your body reacts by ‘getting into gear’, literally activating the chemicals necessary to start energy conversion. Combine with even paltry amounts of food (esp carbs), and the fire is stoked.
I remember from psychology that you sleep in cycles of about 90 minutes (sleep stages). But I recall that as you sleep longer, you’re more likely to be in REM stages, and your cycles are longer as well. So, if you wake up from a long sleep, you’re more likely to wake up in the middle of an REM cycle, which can make you tired.
I’ve found if I’m tired I can take brief naps (as little as 3 minutes to 20 minutes) and feel great when I wake up, and those naps are full of dreams. I think it could be my body trying to complete a previous REM cycle, but I’m no psychologist so that’s just a guess.
Sleep stages is the answer.
It’s the same reason why when you take a nap during the day you sometimes feel worse than when you went to sleep.
You woke up during a deep sleep stage. Graph of sleep stages.
When you go to sleep your body steps down into deeper and deeper sleep (called stages). The first two stages are relatively light sleep and if awoken from them you can react quickly and feel pretty good.
Once your body knows that you are going to sleep for a long time, you will continue into the deep sleep stages (3 and 4). Waking from one of these stages is extremely disruptive and will make you feel fatigued, as your body has been interrupted from a deep restful state.
This is why when you plan to take a nap, set an alarm. Sleep for 20, 30 or 90 minutes. If you awake at the 20 or 30 minute point you will not have entered the deep sleep stages. At 90 minutes you have gone through the first deep sleep stage and can safely wake up before you enter another one. A one-hour nap is probably the worst thing you can plan since you will almost always wake up feeling worse than when you started.
If you oversleep your body continues off the right side of the graph (which is all light sleep stages) and starts all over again, figuring that it has a nice rest coming on. Adding an extra 2 hours of sleep could cause you to wake up in the middle of stage 4 sleep and feel awful for the entire day.
These numbers are general, of course, and your numbers will vary but I highly suggest following some of these parameters. One thing that has worked for me (I fly on the back-side of the clock and have to manage my sleep carefully) is to have my iPod playing at a VERY low volume when I lay down for, say, 2 hours. The low volume allows me to fall asleep but the noise itself prevents my body from going down into stage 4 sleep - I end up waking up every 20 minutes or so and going right back to sleep. I get lots of rest but don’t feel awful when I get up.
Feel free to PM me if you want more info.
http://www.straightdope.com/classics/a990205.html
The Master has some words on the phenomenon.
Of course, if anyone happens to have citations for related effects, that would be totally awesome.
Sorry if this is considered thread necromancy; I figured a month was within reason, and I happen to have recently taken an interest in the subject.
Well I see my previous link no longer works.
Try this link for sleep stages.
Despite what The Master said back in 1999, awakening from Stage 4 sleep will make you feel “worse” than when you went to sleep, without any expectations on your part.
Apophenia thanks for reviving this so I could find my outdated link!