Know what determines whether your morning routine actually works? What you do 12 hours earlier.

Some people spend years perfecting their mornings — the right sequence of coffee, movement and mental preparation. I've always struggled making my mornings consistent, though, and I kept hitting the same wall: some days I woke early, wrote in my journal and sat with my thoughts before lurching for my mobile device ... but most days I didn't. The variable wasn't my morning discipline. It was whether I'd set myself up properly the night before or stayed up needlessly scrolling sports news or the opinion pages of the NYT and WSJ until my body gave up from exhaustion.

The research points to an unglamorous truth: What you do before bed determines how your body repairs itself, consolidates memory, regulates hormones and sets you up to function like a competent human the next day.

Here's how to build an effective nighttime routine that helps you age with strength.

Light is the boss of you

Your body runs on an internal clock that evolved to sync with the sun. Ignore this and you're essentially messing with your biology.

The hack is to search out bright light during the day. Stand outside during a phone call. Eat lunch by a window. Fifteen minutes of morning sun is ideal, but any natural light resets your circadian rhythm and primes your body for deeper sleep many hours later.

Then, at night, reverse course. As the sun sets, try reducing light exposure, particularly the blue wavelengths that scream "daytime!" to your brain and suppress melatonin production. Dim your lights. Wear blue-light-blocking glasses if you must stare at screens. Or go full science-nerd and install red incandescent bulbs that mimic sunset and signal your brain it's time to power down.

Most importantly: mind your exposure to screens. At the very least, dim them after dinner, so you're not inadvertently instructing your body to wake up instead of prepare to sleep.

The stimulant curfew

Simple rule: no caffeine after noon. You may think a 2 p.m. espresso is harmless. Turns out caffeine takes about 10 hours to fully clear your system, meaning that afternoon pick-me-up may still rattle around your neurons at midnight.

Same logic applies to vigorous exercise. Whenever I work out after, say, 6 p.m., I find my body is energized for hours afterward, which usually makes winding down for sleep difficult before midnight. Workouts reduce stress and anxiety but, when done too late in the day, can also leave your body revved when it should be idling. Save that physical intensity for earlier in the day.

The brain sweep

If your mind churns with tomorrow's obligations the moment your head hits the pillow, you're not alone. To empty your brain before bed, put your top three priorities for the next day on paper (try not to use your computer late at night). Prep anything you'll need so it's off your mental hard drive.

This can make the difference between lying awake mentally rehearsing your to-do list and actually sleeping.

Also: hard stop on email and messaging after around 8 p.m. or 9 p.m. at the latest. Because receiving one unexpected email at night can hijack your focus and delay sleep for hours. Protect your evening like you'd protect a decent night's rest, because that's exactly what you're doing.

No food or alcohol three hours before bedtime

Allowing your body time to digest, so it can focus on repair instead of processing food, is essential for building a healthy sleep routine. Finish dinner three hours before bed, and absolutely eliminate nighttime snacks (especially sugary treats and drinks).

Alcohol is anathema to good sleep, which is all I'll say about that. Drink whatever else helps you relax — herbal tea, water with lemon and salt. But avoid taking in a lot of liquid within 90 minutes of sleep, unless you enjoy middle-of-the-night bathroom expeditions.

The temperature trick

A soothing hot shower before bed is a biological cheat code. It raises your core temperature, and the rapid cooldown afterward signals your brain that sleep is imminent. If you have access to a cold plunge, take one after your shower. The calming benefits are consistently good, I've found. Cooling down helps you fall asleep faster and improves sleep quality by syncing with your circadian rhythm.

It also creates a psychological break between your workday and rest day. Your body understands the message: The day's over! Stop trying.

The bottom line

Without quality sleep, you cannot optimize your health. It is really that simple. Thus, your evening routine is really about clearing space for the most important one: sleep that actually restores you and your aging body, which needs the extra consideration.

To find out more about Paul Von Zielbauer and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

Photo credit: Andy Henderson at Unsplash