Often-heard advice for success: “Wake up earlier.” But how much sleep is enough?

Question

A recurring tip I've seen in autobiographies or books on succeeding in business is "wake up earlier." I don't particularly remember which millionaires suggested that advice, but I'm sure it's more than one of them.

Clearly, sleep takes hours out of one's day – hours that could be used to be more productive. So on the surface, "wake up earlier" seems like good advice for those interested in productivity.

However:

• How much sleep is enough? How much is too much?
• When is it too little sleep? What is the point of diminishing returns?
• What about the flip-side; "go to bed later"?

Looking to find that optimal point where both restfulness and productivity are well-balanced.

Good answers will provide pointers to definitive reference material, studies, or data.

Answer 1

Everybody is different. Listen to your body.

I need 7 hrs; 8 is better. Sub-6 and I'll definitely be suboptimal. I know people who are fine on 4. As one gets older one generally needs less sleep.

If you are constantly tired or sleepy, or don't feel like you're working at your full potential, try sleeping more. Animals (not just mammals, but almost all vertebrates as far as I know) sleep for a reason; some theories posit that a good deal of learning (or solidifying of learning) occurs when asleep.

But most importantly, I wouldn't ask others for the answer -- try different amounts, but pay attention to your body. Also, a regular schedule is at least as important as the total amount.

Answer 2

Early to bed and early to rise, makes a man healthy, wealthy, and wise.

-- Ben Franklin

Go to bed earlier. When you wake up (under normal circumstances) you'll have had enough sleep. Take some time to learn what is a normal amount of sleep for you. If you discover it varies significantly from the "average" required amount of sleep, seek professional help.

Once you've determined how much sleep time your body demands, go to bed at a time that will give you that amount of sleep and wake you up at the time most convenient for you. At that point you can experiment with techniques to alter your sleep patterns (multiple shifts, naps, etc) that will help you improve your productivity.

But productivity isn't just for doing more tasks now. It's doing them at a sustainable pace over the long-term. Damaging your body in the quest for maximum productivity would make your whole life less productive, wouldn't it?

Answer 3

I've often read the most important factor in sleeping is not so much how long you sleep but at which point during the sleep cycle you wake up.

Ideally you should wake up during light sleep. In the picture above, REM and above, and stages 1 and 2 would be light sleep. Stages 3 and 4 would be deep sleep. Awakening from deep sleep can lead to sleep inertia (grogginess).

Going by that hypnogram, you can see there is a minimum amount of sleep you should get to avoid sleep inertia, but there isn't an ideal number of hours or minutes.

Each sleep cycle lasts about 90 minutes, and there are alarms you can buy that will only ring during light sleep.

Answer 4

Actually, I would disagree. The biggest way to ensure good productivity is to be in physical condition to perform well, and that requires rest. Two "extra" hours in the morning aren't worth spending the day as a zombie.

You may find however, that time spent alone either before people wake up (if you're a morning person) or after they've gone to be (if you're a night-owl) may make for a productivity boost, but it's better to shift both ends of the night to get a full night's rest rather than shorting yourself.

Answer 5

Shouldn't everyone just sleep 8 hours to have maximum energy? There was a huge study by the American Cancer Society that found that those people who report that they sleep 8 hours have a higher mortality than those who report 6 or 7 hours.

Correlation and causation aren't easy to determine but the data suggests that 8 hours aren't a one-size-fits all solution. Different people seem to have different sleep needs. If you want to find the optimal sleep length for yourself you have to experiment with different schedules.

There are basically two ways to go about finding the optimal sleep length:

1. Listening to your body. Wake up without an alarm clock but by setting an intention to wake up at a certain point in time. Your body will take the amount of sleep that it needs.

2. Numerical. Tools like RescueTime provide you with a numerical rating of your productivity. If one sleep shedule gives you a higher productivity rating you have found your winner.

Is sleep length the only thing that matter? It isn't. Regular sleeping pattern beat unregular ones.

It's also beneficial when you don't directly awake from deep sleep phases. Unfortunately it isn't as easy as Louis suggests above. It's true sleep circle takes on average 90 minutes but that doesn't mean that there no variance.

How do you solve the problem? There are again two solutions:

1. Listening to your body. Don't use an alarm clock. You will naturally wake up when it's convenient for your body.
2. Use technical devices like the Zeo. The Zeo monitors your sleep phases and awakes you at the right moment.
3. Use audio brainwave entertainment to influence your sleep phases. iMusic Deep Sleep would be an example for such a product. (I'm not sure whether this approach works but it seems to make sense on first glance)

Answer 6

There are two schools of thought on this. One is that getting less sleep means more hours a day to do other stuff. Another is that getting more sleep makes you more alert and focused during the hours you are awake. While there are many studies, the answer is usually 6-8 hours for most people. But it depends on the person. You may need less sleep than me.

Answer 7

HUGE subject, with all kinds of individual variability. Standard sleeping versus bi- or poly-phasic sleeping (i.e., not sleeping in one block of time, instead splitting it into more sessions). You can Google around for more detail, but ultimately you'll have to decide what works best. If you try some kind of polyphasic approach the main drawback is having to interact with people who do not share the same schedule as you.

Answer 8

How Much Sleep Do We Really Need?
http://www.sleepfoundation.org/article/how-sleep-works/how-much-sleep-do-we-really-need

Sleep is More Important than Food
http://blogs.hbr.org/schwartz/2011/03/sleep-is-more-important-than-f.html

Answer 9

The main thing is 'regular' as in 'scheduled.' Get your body into a routine and stick with it. I am currently out of sync, and hitting the snooze, but when I get into rhythm, I don't need the alarm. Get some regularity in your schedule and then work on optimizing it for your work.

Answer 10

It is a mistake to interpret the advice "wake up early" as "sleep less".

The book "Brain Rules" discusses how important sleeping is to our brain. Here is short summary: http://www.brainrules.net/sleep

Answer 11

Generally you wouldn't be effective if you regular sleep for the 5 hours a day. There are many theories about how to sleep, and in other questions this point of view are good covered.