The 4-Hour Body: Engineering the Perfect Night's Sleep
“God, what a beautiful beach. Calm. Turquoise water. I should go back to Thailand. I wonder what time it is in Thailand. But why is there a mangy German shepherd on my beach? Orange collar. Kind of looks like John’s dog. Actually, I owe John a call. Did I put his birthday party in the calendar? Birthdays and clowns. Clowns?! Why the hell am I thinking about clowns?!”
That’s Tim Ferriss at 3 AM. Lying in bed, brain spinning through random images and anxieties like a broken slideshow. His body is twisted into some pretzel yoga pose. Then he flips to the fetal position with a pillow between his knees. Fetal position never works, but he keeps trying - like a dog scratching at a door that never opens.
Tim has onset insomnia. His dad has it. His brother has it. They’re not stressed. They’re not wired on caffeine. They just can’t fall asleep.
So he decided to fix it with data.
Chapter 23: Engineering the Perfect Night’s Sleep
Building a Bedroom Sleep Lab
Tim needed to measure what was happening while he slept. Sleep labs are useless for insomniacs - you can’t sleep normally with 22 wires glued to your head in a strange room. So he built a portable setup: a Zeo headband for brain waves, a FitBit and WakeMate for motion tracking, heart-rate monitors, thermometers, continuous glucose monitors, and video recording. All at once.
He looked like a comatose Robocop.
The motion-based trackers (FitBit, WakeMate) turned out to be bad at detecting when you actually fall asleep. Tim tested this by sitting perfectly still watching TV for 30 minutes - the devices logged it as sleep. Not great. But the Zeo, which reads actual brain activity, gave real data.
After four months of tracking, here’s what he found.
Six Things That Actually Matter
1. REM ratio is more important than REM duration. Good mornings (8-10 on his scale) correlated with a higher percentage of REM sleep relative to total sleep. Not more REM in absolute minutes - a higher ratio. Better REM ratio also meant better memory, lower resting pulse, and lower temperature upon waking.
2. Wake up once on purpose. Setting an alarm to wake up for 5-10 minutes about four and a half hours after falling asleep dramatically increased REM percentage. One intentional interruption actually helped.
3. Huperzine-A boosts REM by 20-30%. Take 200 mg thirty minutes before bed. It slows the breakdown of acetylcholine, a neurotransmitter involved in REM sleep and memory. Tim used it for language learning and lucid dreaming. Warning: only use it three days a week max. Overuse causes - wait for it - insomnia.
4. Deep-wave sleep determines physical performance. The higher the percentage of deep-wave (delta) sleep, the better your body performed the next day.
5. Alcohol destroys deep sleep. More than two glasses of wine within four hours of bed cuts deep-wave sleep by 20-50%. The same amount six hours before bed? No measurable effect. Timing matters. On the flip side, 15+ drops of California poppy extract increased deep-wave sleep by up to 20%.
6. Eat before bed. Two tablespoons of almond butter on celery sticks before bed eliminated half of Tim’s terrible mornings. The reason is simple - low blood sugar during the night. You sleep eight hours and wake up exhausted because your blood sugar crashed at 4 AM. A small high-fat, high-protein snack fixes this.
Beating Onset Insomnia
The bigger problem was getting to sleep in the first place. Tim tested everything except prescription drugs. Here’s what worked consistently - meaning it had to work at least three nights in a row.
Cold room: 67-70 degrees Fahrenheit. Single bedsheet. This was the most reliable variable. If you can’t control the thermostat, try socks of different thickness to regulate body heat. Warmer never worked. A bit colder (65F) worked fine with socks.
Big meal before bed. Meals with at least 800 mg cholesterol (four whole eggs) and 40 grams of protein within three hours of bed produced the fastest sleep onset. Two rib-eye steaks had - his words - a “tranquilizer-like effect.”
Blue light in the morning. A Philips goLITE blue-light device used for 15 minutes in the morning, pointed at him from the side. That evening: asleep in under 10 minutes for the first time in weeks. Worked four out of five nights. The light resets your circadian rhythm so your body knows when night actually starts.
Iso-lateral exercise. Regular exercise had unpredictable effects on sleep. But single-arm or single-leg resistance exercises - the kind that require lots of stabilization - produced faster sleep 8 out of 10 times. The more balance required, the faster he fell asleep.
Cold bath one hour before bed. Two to three bags of ice in a half-full bathtub. Ten minutes. First the legs, then upper body (hands stay out). Tim combined this with low-dose melatonin (1.5-3 mg) and described the result as “getting hit with an elephant tranquilizer.” The cold bath alone worked even without the melatonin.
NightWave pulse light. A small device that projects a slow-pulsing blue light on the ceiling. You match your breathing to the light. It slows down over seven minutes, then shuts off. Tim’s friend Michael swore by it - near 100% success rate. Tim found it less consistent but still useful as a backup.
The half military crawl position. Last resort. Lie face down, head on pillow turned right. Right arm bent at 90 degrees near your head. Right knee pulled out to the side, also at 90 degrees. You basically can’t move in this position. Like a self-imposed swaddle. Less fidgeting means faster sleep.
Chapter 24: Becoming Uberman
Now for the crazy part. What if you could sleep only two hours a day and feel fine?
Scientists don’t really know why we need eight hours. Giraffes weigh 1,760 pounds and sleep less than two hours per day. The theory behind polyphasic sleep is that REM is the only phase that really matters - and normal sleepers only get 1-2 hours of REM per night. The other six hours might be waste.
Polyphasic sleep tries to cut the waste.
The Schedules
Tim hands this chapter mostly to Dustin Curtis, a designer with a 28-hour internal clock (a real condition called non-24-hour sleep-wake syndrome). Dustin mapped out five alternatives to normal sleep:
Siesta - One 20-minute nap during the day, plus 6 hours at night. Total: 6 hours 20 minutes. Just adding one nap saves almost two hours.
Everyman - A short core sleep (1.5-4.5 hours) plus 2-5 naps. The more naps, the less core sleep you need. Total ranges from about 2.5 to 5 hours.
Uberman - Six 20-minute naps spread evenly through the day. No core sleep at all. Total: 2 hours.
The trick is that sleep deprivation forces your brain to enter REM immediately during naps instead of cycling through lighter phases first. After a few weeks, your body adapts and drops into REM the moment you close your eyes.
The Catch
The stricter the schedule, the less room for error. On Uberman, every nap must happen within 30 minutes of its scheduled time. Miss one and you feel wrecked for days. Miss one nap and it takes two extra naps to recover.
Matt Mullenweg - the guy who built WordPress - used Uberman for an entire year. He said it was probably the most productive year of his life. He wrote most of his early WordPress code during those extra hours. The first three to four weeks were brutal - pure zombie mode. After that, he didn’t even need an alarm to wake up from naps.
Then he got a girlfriend. That was the end of Uberman.
Should You Try It?
Tim himself used Everyman and Siesta with good results. He reserves Uberman-style schedules for emergency deadlines only. The adaptation period is genuinely awful - weeks of feeling like the walking dead. And it’s completely incompatible with a 9-to-5 job or any social life that involves sleeping next to another human.
The Siesta method, though? Adding one 20-minute nap to save almost two hours of night sleep? That’s practical for almost anyone. Start there.
Previous: Improving Sex and Doubling Sperm Count
Next: Reversing Permanent Injuries
This is part of my 4-Hour Body retelling series. New posts every Saturday.