The Stupidity of Cutting Sleep

Last week I did a live workshop for the students in Learning on Steroids. One of the listeners asked me whether I knew a way to reduce sleep to 5-6 hours and not feel tired. No, I don’t. And you shouldn’t try.

Similarly, when I was in university, I knew people who often bragged about how little sleep they got. To them, it was proof that your studies were impressively difficult and that you weren’t a slacker. To me, it’s proof you’re an idiot.

My goal is to get 8 hours of sleep every night. When I was doing the MIT Challenge, I usually got 9 hours, if you include brief naps during the day. I can’t imagine having done it on less.

Why You Need Sleep to Learn

The true function of sleep isn’t perfectly understood. What is known, however, is the effects of not getting enough of it.

Participants in one study were separated into three groups, getting eight, six and four hours of sleep, respectively. Only the eight-hour group did not see a steady decline in cognitive performance during the study. Sleeping just six hours quickly resulted in a decline in performance equal to being legally drunk.

Sleep is particularly important for learning because it is associated with memory consolidation. Since learning involves storing and organizing new memories, it’s not a process you can omit and still learn well.

Why You’re Not the Exception

Some people can function on less sleep, and there appears to be a genetic basis behind this. But I caution generalizing that result to yourself for an important reason. The participants who underwent sleep deprivation saw a continuous decline in their cognitive performance. However, they stopped feeling more tired after a certain point. That means that the true cost of their fatigue was being masked.

If you regularly sleep less than eight hours, you may have settled onto the plateau of fatigue. You feel tired, but you’ve stopped feeling more tired each day. The evidence shows, however, that your performance has probably continued falling without you noticing.

Manage Energy, Not Time

Cutting sleep is popular because of the myth that you’ll be more productive if you have more hours each day. If you sleep eight hours, you only have sixteen waking hours to do everything. If you sleep six, you now have eighteen. That’s an entire month of waking time added to each year.

The problem is that time is rarely the bottleneck in getting things done. It should only take brief introspection to realize that this is true. Nobody can sustain sixteen hour workdays perpetually, even if such a day would be possible, hypothetically, under time management.

If you’re like the majority of people, even putting in eight hours of focused work is enormously difficult. If you actually do a timelog, you’ll realize that even getting in four is difficult.

So if doing focused work for only a quarter of your waking hours is difficult, it’s clear that number of waking hours aren’t the limited resource. Something else is. And that something else is your level of energy which you can apply to tasks.

Sleep isn’t the only factor for how much energy you have, but it’s one of the foundational components. Cutting sleep isn’t giving you extra working hours to use. It’s eroding the very foundation for doing any real work. I’d rather work atop the energy that comes from being fully rested than trying to shave off work for more time.

How Do You Get Enough Sleep?

Simple: treat it with the importance it deserves. Treat it as the foundation of your productivity, not an unfortunate maintenance task you have to do once a day.

It’s not possible to sleep perfectly all the time. Life will intervene in ways that make it difficult to maintain an impeccable sleep schedule. But there are some steps you can take to do better:

  1. Make eight hours your default. Having unexpected life events force you temporarily into less sleep is inevitable. However most sleep deprivation isn’t this—it’s poor planning resulting in consistently getting too little sleep. Set up your normal schedule so that getting eight hours is a priority for you.
  2. Stop drinking morning coffee. If you need your cup of coffee to stay alive in the morning, you’re not getting enough sleep. Don’t mask the real problem.
  3. Exams are not an excuse for poor sleep. You knew about the exam months in advance, so your studying should be spread evenly to study for it. Sleeping little before an exam to cram not only makes long-term retention of the material incredibly unlikely, but it reduces your cognitive performance making it harder to take the test.
  4. Set a bed time. Figure out when you’re going to wake up. Subtract eight hours. That’s when you should be going to bed. Aim to sleep then, even if you don’t feel especially tired. If you get into a habit of this you will return to normal sleeping habits.
  5. Wake up at the same time, every day. The more consistent you can make your sleep habits, in waking and sleeping, the easier it will be to fall asleep immediately and wake up without agony.
  6. Reduce illumination an hour before sleeping. Light cues are important for the production of melatonin, a trigger for sleep. But if you have screens and lights shining at you until the moment before bed, you’ll have to struggle more to get to sleep.
  7. Stop planning to repay sleep debt on weekends. Yes, weekends can be great for catching up on sleep, but they usually aren’t enough. If you slept five hours for the entire week, getting a normal sleep for two nights won’t recover you fully.

The problem with sleep is that our culture glorifies sleep deprivation. Being sleep deprived is a badge of honor that you’re busy and important. Only the slothful and mediocre sleep well.

Whenever I’ve mentioned getting enough sleep, I see this cultural bias flare up. People respond with how others may be able to sleep eight hours, but for them it is truly impossible. They’re just too busy and important to get it all done and still sleep.

I can’t imagine those same people declaring, with pride, that they don’t have enough time to bathe.

Yes, getting enough sleep is hard. Just like exercising regularly, eating healthy and, of course, personal hygiene. No, you can’t do it perfectly all the time. But you can recognize its role in making you more productive and strive to make good sleep the default, not the exception.


Here’s some other good links on sleep and energy: