The 24-Hour Sleep Model: Why Better Sleep Starts the Morning Before

These days I help lead one of the Bay Area's most active longevity communities. People assume someone in my position has always had their health dialed in.

Three years ago, the opposite was true. On paper my life looked enviable — a product manager at a major tech company — but underneath I was coming apart. I was working 996 (9 to 9, six days a week), new to a city where I knew no one, eating badly, never moving. And I was sleeping terribly: lying down exhausted but taking forever to fall asleep, waking at 3am with my mind already running. I tried the usual fixes — blackout curtains, magnesium, earlier bedtimes — and none of them touched what was actually wrong.

Today I sleep well almost every night. Not perfectly, but the bad nights don't snowball anymore, because I can trace each one to a cause and correct it the next day. 

And it shows up in the data. Comparing my first months in that job to a recent stretch three years later, my own tracker tells the story:

• Time awake in the middle of the night: cut roughly in half
• Deep sleep (the physically restorative stage): up about a third
• REM sleep (mental and emotional recovery): up around 60%
• Sleep efficiency: climbed from 88% to 93%

Same body, same tracker. The only thing that changed was how I built my day.

I call it the 24-hour sleep model. The core idea is simple: the quality of your night is mostly decided by what you do while you're awake. The hour after you get up matters as much as the hour before bed. Your light exposure at 7am, when you eat your last real meal, how you discharge stress at 2pm. These shape your sleep more than any bedtime ritual. If you only intervene at night, you're trying to fix a problem that was set in motion twelve hours earlier.

One important caveat before we start: this is about optimising normal sleep, not treating a sleep disorder. If you snore heavily, gasp awake, have restless or crawling legs at night, or suspect a condition like sleep apnea or insomnia disorder, no amount of light timing or routine will fix that. See a doctor. What follows is for people whose sleep is basically functional but who want it to be meaningfully better.

Here's how the model works, and how you can build your own version of it.

The three drivers of sleep

Most sleep advice is a flat list of tips, a hundred things you "should" do, with no way to know which ones matter for you. The 24-hour model organises everything around three biological systems. Almost every sleep problem traces back to at least one of them being out of balance.

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Body clock (circadian rhythm)

This is your internal 24-hour timer, set primarily by light [1]. It governs when your body releases melatonin at night and cortisol in the morning. When your clock is aligned, you get sleepy at a consistent time and wake feeling alert. When it drifts, from late-night screens, dim mornings, erratic schedules, or travel, your body simply doesn't know when it's supposed to sleep.

Sleep drive (sleep pressure)

From the moment you wake, a chemical called adenosine builds up in your brain, creating a growing pressure to sleep [2]. The longer you're awake and active, the stronger it gets. Naps, caffeine, and a sedentary day all bleed off or blunt that pressure, so by bedtime there isn't enough of it to carry you into deep sleep.

Quiet mind (nervous system state)

You cannot fall asleep while your body is in fight-or-flight [3]. If your sympathetic nervous system is still activated at night, from stress, late work, intense exercise, or doomscrolling, your heart rate and cortisol stay elevated and override every other signal. This was my single biggest problem, and the one I'd been completely ignoring.

The power of these three is diagnostic. Once you can name them, a frustrating, vague problem ("I sleep badly") becomes a specific, solvable one ("my sleep drive is too low and my nervous system is too activated"). And a specific problem has a specific fix.

My 24-hour routine

Here's what a typical day looks like for me now. For context, I'm a natural morning type, up around 6am, asleep by 10pm, and every time below is anchored to those two points. Shift your own wake and bed times and the whole routine shifts with you. Notice how much of it happens nowhere near my bed. Each habit is tagged with the system it serves, so you can see the logic rather than just the list.

• 6:00am: Lux light box immediately on waking. (Body clock)
• Within 30 minutes: morning sunlight while walking my dog. (Body clock)
• Weights / cardio. (Body clock + sleep drive) [4]
• By 4:30pm: last real meal. (Body clock + quiet mind)
• 5:00pm: walk my dog for evening light and a post-meal glucose buffer. (Body clock + sleep drive) [5]
• 8:30pm: phone down. (Quiet mind + body clock)
• Sauna (heat before bed). (Sleep drive + quiet mind) [6]
• Dim light and blue-light blocking glasses. (Body clock + quiet mind) [7]
• Journal. (Quiet mind)
• 10:00pm: consistent bedtime. (Body clock)

You'll notice the actual "sleep" part is almost an afterthought. By the time I lie down, the work is already done. That's the entire point.

How to build your own version

You should not copy my routine. The whole premise of the 24-hour model is that the right protocol depends on which system is failing for you, and that's different for everyone. Here's the loop I use, and recommend, for figuring that out.

Step 1: Map your schedule, then find the system that's failing

Before you change anything, anchor two things: your chronotype (are you a natural early riser, a night owl, or somewhere in between?) and your real wake and sleep times. This matters because every protocol is timed off those two anchors. "Morning light" means within an hour of your wake-up, not a fixed clock time, and "last meal a few hours before bed" depends on when your bed is. A night owl forcing a morning lark's schedule will fight their own biology no matter how perfect the protocols are.

Then find which of the three systems is dragging you down. Use these rules of thumb:

• Takes you a long time to fall asleep, but you're not wired? Likely a sleep drive problem, not enough pressure built up. Look at how active and how nap-free your days are.
• Lie down exhausted but your mind races, heart won't settle? Likely a quiet mind problem, your nervous system is still activated. Look at stress, late work, and evening stimulation.
• Can't fall asleep at a reasonable hour, or wake up groggy no matter how long you slept? Likely a body clock problem, your rhythm is misaligned. Look at light exposure and schedule consistency.
• Wake repeatedly in the second half of the night? Often body clock or quiet mind, frequently tied to late meals, alcohol, or elevated cortisol.

Step 2: Pick one targeted change for that system

Don't reach for the habit that's easiest or trendiest. Reach for the one that addresses your weakest system. If your sleep drive is low, adding more morning light won't help much. Getting more daytime movement will.

Step 3: Change one thing at a time

This is the rule almost everyone breaks. If you overhaul five habits at once and your sleep improves, you've learned nothing about which one worked, and you can't troubleshoot when it stops. One variable at a time is slower, but it's the only way to actually learn your own system.

Step 4: Give it two weeks, then keep or cut

Sleep is noisy night to night, so don't judge a change on a single bad night. Watch the two-week trend. If a habit clearly helps, it stays and becomes part of your baseline. If it does nothing, drop it without guilt and try the next candidate for that system.

Step 5: Move to the next system

Once you've stabilised your weakest system, reassess. Often fixing the first one reveals the next bottleneck. Sleep optimisation isn't a destination you arrive at. It's a loop you run, getting a little more precise each cycle.

This is essentially running small experiments on yourself, with your three systems as the hypothesis space and your own sleep as the data. It's not as fast as swallowing a pill. But it produces something a pill never can: a sleep system that's actually yours, that you understand, and that you can repair when life inevitably knocks it out of balance.

The shift that actually matters

The reason I struggled for so long wasn't that I lacked discipline or information. I had read every sleep tip there was. What I lacked was a model, a way to connect what I did all day to how I slept at night, and a way to know which lever to pull.

The 24-hour sleep model gave me that. It turned sleep from something that happened to me into something I could engineer. And the most freeing part was realising that the night was never really the problem. The night was just where the results showed up. The real work, and the real opportunity, was in the fifteen hours before my head ever hit the pillow.

Main Take-Away: If you've tried everything and your sleep still won't budge, you may not have a willpower problem or a melatonin problem. You may just be intervening at the wrong hour of the day. Find your weakest system, change one thing, give it two weeks, and start the morning before. That's where better sleep actually begins.