A friend of mine wears fatigue like a badge of honor. He knows he should sleep more, but there's just too much to do. 

"I'll have plenty of time to sleep when I'm dead," he likes to say.

So his goal is to make the sleep he does get as effective as possible. He uses "temperature regulating" sheets. He uses a special light that works in conjunction with his alarm to "optimize" how he wakes up. He wears $200 "recovery" pajamas designed to help him to fall asleep faster, sleep better, and even reduce inflammation.

As he puts it, a combination of science, technology, and disposable income lets him cram all the rest and recovery he needs into four hours of sleep.

He's not unusual. Plenty of people, especially startup founders, tend to brag about how little sleep they get.

And plenty of people claim they don't need much sleep: Some because they believe they're genetically able to thrive on four or five hours of sleep each night, others because they believe they're tough enough to push through.

But here's the thing. Actually only needing four to five hours of sleep a night is highly uncommon; only a fraction of the population is built that way. Which means, much as we might like to believe otherwise, it's highly unlikely you're built that way. (I'm definitely not -- I'm pretty much average in all things.)

As for the people who feel they're tough enough to get by on limited sleep, they're right... and wrong.  Within a few days, loss of sleep diminishes your sleep drive and affects your normal perception of "sleepy." 

So you think you're doing fine... but any task that requires focus, deep thinking, or problem-solving gets a lot harder. Research shows that where reaction time and attention are concerned, only sleeping for six hours is like drinking a couple of beers, and only sleeping for four hours is like drinking five beers. 

So yeah: Not getting enough sleep is like trying to work with a decent buzz.

What Happens When You Sleep

Granted, my friend is on to something. What you wear in bed can affect your quality of sleep. So can the room temperature. So can the comfort of your sheets. So can light, noise, humidity, etc.

Creating an environment for a great night's sleep makes perfect sense.

But thinking that you can fast-track the benefits of sleep and cram them into a shorter window doesn't. Sure, quality matters. 

But so does time.

That's because there are four basic stages of sleep. In stage one, you go from wakefulness to sleep, normally in five to ten minutes. (If it takes you thirty minutes to go to sleep, for twenty or so of those minutes you were just awake.)

In stage two, your body temperature drops, your heart rate slows, and some degree of memory processing takes place. Stage three is where much of the magic happens: More memory processing occurs (some factual memories get encoded while others get dropped), tissue repair kicks into overdrive, muscles get built, etc.

Stage four, the REM stage, is not just when you're most likely to dream, but also when process-oriented skill (think motor and cognitive) get encoded. And then the cycle begins again.

All of which means means only sleeping for four hours makes it harder for you to learn, harder for you to improve a skill, harder for you to make smart decisions, harder for you to deal with stress, harder for your body to repair and rejuvenate itself... pretty much everything that matters, gets harder.

So while it's possible to go on limited sleep for weeks on end, to paraphrase Chris Rock: You can do it, but that doesn't mean it is to be done. 

How Much Sleep Do You Need?

Most people fall in the seven to nine hours per night range. An easy way to find out where you fall is to go to bed at a normal time, making sure the room is quiet, dark and cool -- 65 degrees is generally thought to be optimal -- and don't set your alarm.

Do that for a few days, and see when you wake up. (It might take a few days for you to know for sure. If you're chronically sleep-deprived, for the first couple of days you might be in catch-up mode. And it also might take you a couple of days to get past the "I'm too busy to sleep" thing.)

See when you wake up as a place to start. Again, you'll likely fall in the seven to nine hour range.

Then adjust your schedule so you can get that much sleep every night.  Maybe you'll go to bed a little earlier, or wake up a little later. Or maybe you'll take steps to make falling asleep quicker: Avoiding screens for thirty minutes before bedtime, not going to bed feeling too full, making sure the room is dark and quiet and cool...

Do that, and you won't need a tracker to quantify your sleep. You won't need cool new sleep technology.

If you work hard -- if your job challenges you mentally, physically, and emotionally -- sleep is the best way to recover and recharge. 

See if that way, and getting the right amount of sleep tonight won't feel like something you have to do. 

Getting the right amount of sleep will be something you will want to do.

Because it will help you perform better tomorrow.