Deep Dive on Sleep Hygiene: Past Tips & New Hacks
BLACK IRON RADIO EP. 361: Deep Dive on Sleep Hygiene: Past Tips & New Hacks
You already know you should be sleeping more. This episode is about actually making it happen.
Morgan, Ryann, and Nic get into both the fundamentals you need to have in place and the newer research most people have not heard yet. They cover why poor sleep does more damage to your nutrition progress than a bad diet day, what your circadian rhythm actually is and why wrecking it on weekends is basically giving yourself jet lag on purpose, and the surprising research on hot showers before bed. Plus mouth taping, temperature regulation, why the little standby light on your TV might be ruining your sleep, and what social jet lag is doing to your body even when you think you are catching up on rest.
This one is dense with good science, and still very funny.
Sleep is one of the most underrated pillars of health, and it shows up constantly in nutrition coaching in ways people don't always expect. When clients sign up to work on their food, they're not usually thinking, "I bet we'll be talking about my sleep habits." But sleep disrupts hunger hormones like ghrelin and leptin, can push your body toward breaking down muscle instead of fat, and quietly undermines every lifestyle habit you're trying to build. If you've had a bad night and you're trying to reach for the smarter food choice the next morning, your cravings for sugar and high-carb energy hits are going to be physiologically stronger. You're just making it harder on yourself.
In this episode of Black Iron Radio, Morgan sat down with coaches Ryann and Nic to go over both the tried-and-true foundations of sleep hygiene and some of the newer, emerging research on what actually helps.
The Basics: What We Already Know
A lot of what we talk about with sleep hygiene comes back to two things: schedule and environment. Both are connected to your circadian rhythm, your body's internal 24-hour clock. The control center lives in the suprachiasmatic nucleus in your hypothalamus, and it regulates everything from melatonin and cortisol levels to body temperature, mostly in response to light and dark signals from your environment.
There's a fascinating study from 1938 called the Mammoth Cave study, where two researchers locked themselves in a cave for about 30 days to see what would happen to their sleep schedule without any light or dark cues. They managed to shift their sleep patterns to a 25 or 26-hour day, but certain physiological markers like body temperature remained consistent on a 24-hour cycle no matter what. Some of this rhythm is intrinsic. But a lot of it is shaped by your environment, which is exactly where sleep hygiene comes in.
Darkness matters more than you think. Light coming in through your closed eyelids can suppress melatonin and spike cortisol. That tiny indicator light on your TV that you never notice during the day? In a dark room, it's basically a floodlight. Get the room as dark as you can, or use an eye mask.
Your body needs to cool down to sleep. Core body temperature has to drop about two to three degrees to initiate deeper, more restorative sleep stages. A cooler room supports that process.
The phone is a two-problem situation. It emits blue light that suppresses melatonin, and it delivers an endless scroll of everything wrong with the world directly to your nervous system right before you're supposed to rest. Both things independently make sleep worse.
Consistent sleep and wake times may matter more than total hours. This is a little bit of a hot take, but if you're a 10 PM to 6 AM person on weekdays and a 1 AM to 11 AM person on weekends, you're basically giving yourself jet lag on a weekly basis. Your body doesn't care that it's Saturday.
The Hot Shower Hack (Done Right)
Most people have heard that sleeping in a cool room helps. What's newer is research suggesting that a hot shower taken one to two hours before bed can actually support your body's natural temperature regulation process.
Here's why: in the evening, your body is already working to release heat, mostly through your hands and feet. A hot shower accelerates that cooling process. You get warm, your body responds by ramping up heat release, and by the time you're actually in bed, your temperature has dropped. The key is timing. If you shower and go straight to bed, you'll just be hot. You need that hour to an hour and a half for the swing to happen.
Ryan has tested this and found it didn't work great for her personally, since she tends to run warm. Her workaround: ending the shower with a minute or two at a cooler temperature, which gave her some of the benefits without the heat staying on too long. Think of it as a little contrast therapy.
For people who have to train late in the evening and don't have three hours to downregulate before bed, jumping into a hot shower right after the workout is a solid first move. Follow that with an easily digestible dinner, dim the lights, and aim for at least 90 minutes between finishing your training and getting into bed. That window is when cortisol should be actively declining and melatonin should start to rise.
Cortisol, Stress, and Why 3 AM Hits Different
Spanish has a word for it: madrugada. That limbo time between late night and early morning, roughly 2 to 4 AM, when your cortisol naturally starts to climb again. It's why so many people wake up during that window feeling inexplicably stressed or alert. You're not imagining it. You're just in your most sensitive sleep phase, and your nervous system is primed to respond to anything.
Healthy cortisol should peak 30 to 45 minutes after waking, then gradually decline through the day, hitting its lowest point around midnight. When that curve is flat, spiked, or inverted, sleep and stress both suffer.
A few common habits that wreck the curve:
Checking your phone first thing in the morning creates an immediate cortisol spike. Nic, who Ryann coached for a while, eventually moved his phone to another room entirely. Turns out he also started using an app called Brick that blocks social media during certain hours, so even when he picks up his phone, Instagram just doesn't open. That small moment of friction is enough to interrupt the automatic scroll reflex. As Morgan put it, it's a chemical. These platforms are designed to deliver quick dopamine hits, and your brain responds the same way whether the content makes you happy or not.
Eating late at night can trigger digestive activity that competes with sleep, though this is highly individual. Ryann can eat right before bed without any issue. Some clients can't eat within two hours of sleep or they'll be up all night. Know yourself here, and if heartburn or indigestion is in the picture, pull your eating window back.
Overtraining without adequate recovery keeps cortisol elevated for 24 to 48 hours, making it harder for it to come down at night. Elevated cortisol also signals the liver to release glucose without eating, which can raise blood sugar during sleep and disrupt your cycle in ways you might not even register as waking up.
Melatonin: What It's Actually For
Almost all of the Black Iron coaches take a position on melatonin that surprises clients: it's not a nightly supplement.
Taking melatonin every night can lead to psychological reliance and reduced effectiveness over time. The situations where it makes more sense are shift work, where your schedule flips between days and nights, and large time zone changes, like traveling from the US to Thailand. For most people on most nights, it's not the right tool.
Nic admitted on the podcast that he had been taking 10 milligrams nightly for a stretch, which is, as Ryann confirmed with audible alarm, way more than necessary. The physiologically effective dose is closer to one milligram, and going above that is where tolerance tends to build. If you're dealing with significant sleep issues and want to use melatonin temporarily, four weeks on followed by a break is a more structured approach than indefinite nightly use.
A note for anyone with restless leg syndrome: melatonin can significantly worsen symptoms. Worth knowing before you reach for it.
Foods that contain small amounts of melatonin precursors include tart cherry juice (yes, that TikTok trend has some basis), kiwis, walnuts, and pumpkin seeds. You'd need to eat a lot of any of them to produce a noticeable effect, but incorporating them as part of a wind-down routine isn't a bad idea.
Caffeine, Blood Sugar, and Nutrition Timing
There's a large genetic variation in how quickly people metabolize caffeine. Most people clear it in two to three hours. Some people still have it in their system 10 hours later. A general rule of thumb if you're struggling with sleep: cut off caffeine by 1 or 2 PM. That gives you a comfortable buffer to be in bed by 10 or 11.
Here's the part that catches people off guard: even if you fall asleep fine after late caffeine, it can still reduce your deep sleep by up to 20%. You wake up feeling okay but slightly off. You drink more caffeine to compensate. The cycle repeats. If you've been on that hamster wheel for a while, it might be worth backing off the afternoon coffee and seeing what changes.
Meal timing is also worth treating like a sleep variable. When you eat, your digestive system sends peripheral timing signals to your organs. Keeping your eating window consistent reinforces your circadian rhythm and supports natural melatonin production. If you always eat between 8 AM and 7 PM, maintaining that window as consistently as possible helps your body clock run more accurately.
One nuance around nighttime eating: a large carb-heavy meal right before bed raises blood sugar, which triggers an insulin response. If your blood sugar drops while you're asleep, that can signal cortisol to release glucose, causing a micro-wake period that you may not even remember. You might not open your eyes, but your slow wave sleep gets interrupted. If you want something before bed, something with roughly equal parts protein and fat, like Greek yogurt or a small handful of nuts, tends to be a more stable option than cereal.
Breathwork and the Nervous System
Breathwork doesn't get enough credit as a sleep tool, especially for people whose brains won't quiet down at night.
The two most common methods are 4-7-8 breathing (inhale for four counts, hold for seven, exhale for eight) and box breathing (equal counts on inhale, hold, exhale, and hold again). For anxious people, a longer exhale than inhale is the key mechanic. That pattern activates your vagal nerve, which is the main driver of your parasympathetic, or rest-and-digest, nervous system.
A narrative review published in PMC found that slow nasal diaphragmatic breathing, which is the category both of those methods fall into, significantly improves vagal tone, heart rate variability, and parasympathetic activity while reducing cortisol, anxiety, and stress. Humming and a specific lip-touch breathing technique also activate the vagal nerve for some people.
The catch: like most skills, breathwork doesn't work on night one. Repetition is what builds the response. Do it consistently and your nervous system starts to associate the pattern with coming down.
Apps like Calm and Headspace have structured breathing sessions if you want guided support. There are also free options on YouTube. Nic's household calls the racing thought spiral "monkey mind," and he's found that a short guided breathing session is often enough to interrupt it and fall asleep before he even realizes he's stopped thinking.
Morgan's personal recommendation: a podcast called Nothing Much Happens, where the host tells very deliberately boring stories, then tells the same story again at a slower pace. She says she never makes it to the second telling. The idea is that following an external story redirects attention away from the mental loops that tend to keep people awake.
Supplements Worth Knowing About
Magnesium glycinate is the one almost every Black Iron coach recommends and most of them take. Most Americans are deficient in magnesium, so a doctor is likely to clear it without hesitation. It regulates GABA, the calming neurotransmitter, and supports muscle relaxation. Glycinate is the most bioavailable and easiest-to-digest form. Magnesium oxide is less absorbed and magnesium citrate can cause digestive issues, so the glycinate form is the better choice for sleep support.
Ashwagandha is an adaptogen that can help reduce cortisol and improve sleep quality, but it takes four to eight weeks of consistent use before it becomes effective. In a world where we're used to same-day delivery, that kind of patience is hard to sustain, which is why it works for some people and gets abandoned by others.
L-theanine Morgan has taken for general stress support, both morning and night, and noticed a genuine difference in her baseline stress levels. It won't knock you out, but for people who run anxious it can take the edge off.
THC works for some people, and certain formulations and strains are designed specifically with sleep in mind. But like melatonin, it can create reliance if used every night, and research shows it reduces deep sleep and REM. Long-term nightly use tends to mean poorer sleep quality when it's not present, even if it helps you fall asleep initially.
Nic put it well: supplements are enhancers for an existing sleep routine, not a fix for having no sleep routine. If your schedule is inconsistent, your room is too warm, you're on your phone until midnight, and you're eating a heavy meal right before bed, no supplement is going to overcome all of that.
Naps: Useful, But Strategic
There's a natural dip in circadian rhythm in the early afternoon, roughly 1 to 3 PM, which is why post-lunch drowsiness is so universal. A 10 to 30 minute power nap during that window can be genuinely restorative.
The problem is sleep inertia, which is what happens when you sleep for two to four hours and wake up groggy, disoriented, and essentially useless for the rest of the afternoon. That kind of nap also tends to make it harder to fall asleep at your normal bedtime. Short and intentional is the move. Long afternoon naps are usually a liability.
The "Buy It or Bullshit" Breakdown
Cold exposure right before bed: Bullshit. A cold plunge or cryotherapy session spikes your sympathetic nervous system into fight-or-flight mode. That is the exact opposite of what you want happening before sleep. A cool room or a tepid rinse at the end of a hot shower is very different from jumping into a cold tub. Don't do this.
Morning light exposure: Buy it. Getting natural light first thing, even 10 minutes outside, is one of the most well-researched circadian rhythm tools available. It suppresses melatonin, signals your body that the day has started, and essentially sets a timer that helps you wind down more naturally that evening. A sunrise alarm or light therapy lamp is a reasonable substitute in winter months.
Sleep tracking devices: Buy it with caveats. Data over time can reveal patterns worth knowing about. But checking your numbers before you check in with how you actually feel is a trap. Nic's suggestion: use it to spot serious interruptions and trends, not to chase a nightly score. The concept of orthosomnia, getting so focused on optimizing sleep that the obsession itself disrupts sleep, is a real thing.
Mouth taping: Bullshit. There's no solid science behind it, and more importantly, it treats a symptom rather than a cause. If you're mouth breathing at night, the real question is why. Is it nasal congestion? Structural issues? Early signs of sleep apnea? Those are the things worth addressing. And if you're going to tape your mouth regardless, please just use regular tape. The branded sleep tape products are not worth the money.
Weighted blankets: Mixed, and personal. Research shows the most significant benefits for people with anxiety-driven sleep issues or those who respond well to proprioceptive pressure. Ryann sleeps with both a weighted blanket and a weighted eye mask and finds them genuinely helpful. Nic runs too hot and wakes up sweating through his shirt within an hour. If you tend toward anxiety and don't overheat, a weighted blanket is probably worth trying. If you run hot or dislike the sensation of weight, it'll do more harm than good.
One Hack to Try This Week
The team's picks for a seven-day sleep experiment:
Morgan: Get 10 minutes of morning sunlight within the first hour of waking up. Go outside if you can. This one has the most research behind it and it costs nothing.
Ryann: Build a consistent bedtime routine with a mental wind-down practice, whether that's box breathing, a brain dump, or just a few minutes without screens. The ritual itself matters as much as any single element of it.
Nic: Put your phone somewhere that isn't your bedroom. Across the room at minimum. The kitchen is better. The friction of having to get up to access it is usually enough to break the reflex.
Pick one. Give it a full seven days. See what shifts.
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If you enjoyed this conversation, check out more episodes of Black Iron Radio, where we cut through the noise and give you real, no-BS advice on feeling, performing, and looking your best. Each week we share practical nutrition, training, and wellness strategies and tips to help you succeed.
