Sleep is the foundation of health: the science says the percentage of people who can survive on less than seven hours of sleep without impairment, rounded to a whole number, is zero. After my first sleep episode generated a flood of emails, I went back to Matthew Walker's Why We Sleep and found his one-hour conversation with Michael Gervais on Finding Mastery. In this Physical Friday I recap the eye-opening numbers — from an NBA player's stats to daylight savings heart attacks — and Walker's five rules for better sleep.
Listen now: press play in the player above and follow along.
Matthew Walker opens with a quote I cannot forget: from the scientific evidence we have, the number of people who can survive on less than seven hours of sleep without showing any impairment, rounded to a whole number and expressed as a percentage of the population, is zero. No matter your opinion of yourself, on six hours of sleep the evidence shows you are significantly impaired.
Walker cites data from NBA player Andre Iguodala comparing games on less than eight hours of sleep versus more than eight. With more sleep he had a 29 percent increase in points per minute, a 12 percent increase in minutes played, a 9 percent increase in free throw percentage, 45 percent fewer fouls, and 37 percent fewer turnovers. In a game where athletes fight for one percent improvements, that is the difference between a high-level player and someone who does not get drafted.
There is roughly a 40 percent memory deficit when you are even a little sleep deprived, and it worsens the less you sleep. Men sleeping four to five hours a night have the testosterone level of a man ten years their senior. Sleeping five hours versus eight makes you about ten times more likely to catch a cold. If you are training hard for gains but sleeping five hours, the lack of sleep is undercutting everything you do in the gym.
Walker calls it an experiment performed on 1.6 billion people across 70 countries every year. In the spring, when we lose an hour, heart attacks increase about 24 percent the following day. In the fall, when we gain an hour, they decrease about 21 percent. The same profile shows up in other areas — even judges hand out harsher sentences the day after the spring change.
Regularity first: go to bed and wake up at the same time every day, including weekends, to anchor your sleep. Darkness: dim the lights an hour before bed, ditch screens, and let melatonin do its job. Temperature: keep the room cold, because your body needs to drop about two degrees Fahrenheit to initiate and maintain sleep. Then watch caffeine and alcohol — caffeine's half life is six hours, and alcohol sedates you, which is not the same as sleep.
His conversation with Michael Gervais on the Finding Mastery podcast is only an hour and it is really good — that is the one I recommend if you do not have fourteen hours for the Why We Sleep audiobook or three and a half hours for his Joe Rogan appearance. Search Finding Mastery with Dr. Matthew Walker.
A couple of weeks ago I did a podcast on sleep and got a pile of emails about it. First things first: I am not a sleep expert. I am as guilty as anyone of saying I will sleep when I am dead. But the more I learn, the more I have prioritized sleep in my own life — so I went back, reread chapters of Why We Sleep, and found the Finding Mastery episode that packs the essentials into an hour. Press play in the player above for the full recap.
My default move was always to extend the day by shrinking the night — stay up later, get up earlier, grind. The data in this episode goes completely against that. The testosterone numbers, the memory deficit, the cold-virus susceptibility, the NBA performance swings: it all says that sacrificing sleep is sacrificing performance everywhere. What if the biggest gain available to you was doing more of the easiest thing in life — sleeping? I unpack it in the episode, so press play in the player above.
This is the recap of Walker's suggestions that I walk through in the episode, along with what I changed in my own bedroom.
I walk through each of these in the episode. Press play in the player above.
Improving my sleep was the easiest change to feel. A vitamin leaves you guessing; a great night of sleep makes you feel like a million bucks the next day, no doubt about it. These tips come from someone who has dedicated his entire life to studying sleep, and they are very beneficial to your performance — especially in the gym.
I really want to get Matthew Walker on this podcast — I have so many more questions for him. Let me know if you want to go deeper on sleep at podcast@saltwaterexperience.com, and tell me how your own sleep journey is going. Press play in the player above.
Matthew Walker · Why We Sleep · Michael Gervais · Finding Mastery · Joe Rogan · Andre Iguodala · circadian rhythm · melatonin · caffeine half life · daylight savings time · Physical Friday · Saltwater Experience
Physical Friday is my weekly fitness series for fishing guides, anglers, hunters, and outdoorsmen — the training, nutrition, and mindset to stay in the game for life. Watch and listen to every Physical Friday episode from Tom Rowland.
I'm Tom Rowland, a professional fishing guide based in the Florida Keys, host of the Tom Rowland Podcast, and the longtime host of the Saltwater Experience television show. On the podcast's Physical Friday series I share the workouts, nutrition, sleep, and mindset practices that keep me ready for long days on the water — practical fitness for fishing guides, anglers, hunters, and anyone who wants to stay in the game for life.
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