How Much Sleep Is Enough? How Much Is Too Much?

You’ve heard it before: “Everyone needs eight hours of sleep per night.”

A study out of the University of California, San Diego paints a different story. The 2010 paper suggests the secret to a long life has to do with getting just enough sleep, not necessarily eight hours of sleep per night.^[1] The study looked at 1.1 million people’s sleep patterns over the course of six years, tracking the amount of sleep each subject averaged alongside their longevity.

Its major finding: Sleeping as little as five hours per night can be better for you than sleeping eight.

How much sleep do you really need?

The study was run by Dr. Daniel F. Kripke, MD, a professor of psychiatry specializing in sleep research and aging. Researchers didn’t find any statistical health-related reason to sleep longer than six and a half hours per night.

He used data from the Cancer Prevention Study II (CPSII) from the American Cancer Society that shows sleeping for about five hours per night is slightly safer than sleeping eight. In this case, we’ll go ahead and define “safer” as “not dying.”

The UCSD study’s data is impressive. The data is from 1982-1988 because it took years to input the data and analyze it. It covers 1.1 million participants, and it is the first large-scale population study that correlates sleep with longevity while taking into account things like age, diet, exercise, health problems and smoking.
I’m not sure where the sleep-8-hours-per-night myth came from, but it’s totally wrong. You can file it away under old information, along with the eat-fewer-calories-to-lose-weight myth.

Mental and physical benefits of sleep

Doctors, health experts and athletes agree that getting consistent, quality sleep is critical. Here are just a few studies that prove just that:

More Sleep From Bulletproof

When to Take Vitamin D and How It Affects Your Sleep

6 Ways to Improve Sleep Using Food

Your Sleep Chronotype Is the Key to Productivity, Not Being a Morning Person

We Tested Four Sleep Tracker Apps and Wearables: Here are the Best Ones

The mental benefits

• Improves your ability to learn new motor skills by 20 percent^[2]
• Increases your ability to gain new insight into complex problems by 50 percent^[3]
• Enhances well-being and mood^[4]

The physical benefits

• Good sleep promotes skin health and a youthful appearance.^[5]
• Sleep increases athletic performance.^[6]
• Sleep helps regulate your hormones and may even increase testosterone levels.^{[7] [8]}

If sleep is so awesome, why get less of it? The short answer is: It’s the quality of your sleep that matters, not the quantity.

How to hack your sleep

If you find that you need a ton of sleep, your body is trying to tell you something. Stress, over-exercising and diet are all common reasons you might find yourself feeling so fatigued. That’s where biohacking comes to the rescue.

• Learn how to sleep smarter, not longer with these Bulletproof sleep solutions.
• Try these seven sleep hacks to improve your shut-eye, starting tonight.
• If you want to fall asleep easier, avoid blue light after dark. Get the details here.
• Beat stress, fall asleep and stay asleep with my own natural solution for more restful and refreshing sleep: Bulletproof Sleep Mode. It combines L-ornithine and plant-sourced melatonin in a dose that will help you sleep better, faster, without leaving you groggy the next morning.