Introduction
For years, I thought I had sleep figured out. I was running on four to five hours a night, waking at 3 or 4 AM with my brain racing through my to-do list, and I'd just get up and start my day. I told myself I was fine.
Looking back now, I wasn't fine. I was running on cortisol and stress hormones – my body was in survival mode. We have two opposing neurologic systems, the sympathetic and the parasympathetic.They should operate in a balanced manner. Mine was dominated by the sympathetic.
These days, I'm doing things differently. I go to bed around 9 or 10 PM and aim for a solid seven hours. My Garmin Fenix tells me my body battery has improved and is now often in the 90% range when I wake up. My goal is 100% – that's what really good sleep looks like.
What changed my thinking was discovering why we actually need sleep in the first place. Scientists just cracked the code, and it's not what anyone expected.
Before I share what I learned, I want to understand where you're starting from.
Why We Need Sleep
For decades, scientists guessed about why we need sleep. Memory consolidation, hormone balance, immune function – all good theories, but none explained why every creature with a brain absolutely must sleep or die.
Then researchers at Oxford figured it out by studying fruit flies.
Here's what they discovered: Your mitochondria – those tiny power plants inside every cell – produce energy all day long. But the process isn't perfectly clean. It's like a car engine producing exhaust. Your mitochondria leak electrons, and when those electrons hit oxygen, they create nasty molecules called reactive oxygen species (ROS).
Think of ROS like sparks flying off a grinding wheel. A few sparks? No problem. But let those sparks accumulate and you've got a fire hazard.
Your brain forces you into sleep when those toxic sparks build up to dangerous levels. It's literally an emergency shutdown to prevent permanent damage to your neurons.
The breakthrough came when researchers modified fruit flies' mitochondria to reduce electron leakage. Those flies needed less sleep. When they increased the leakage, the flies slept longer and deeper.
This isn't just a fruit fly thing. The same mechanisms exist in humans.
Here's where it gets interesting: the amount of electron leakage – and therefore how much sleep you need – is largely determined by what fuel your body burns.
When I was running on four to five hours of sleep, I thought I was efficient. Turns out I was just stressed. My body was pumping out cortisol to keep me going, and the second I'd wake at 3 or 4 AM, my brain would take off – planning, problem-solving, worrying. There was no going back to sleep once that started, so I'd just get up and begin my day.
I wasn't optimizing my mitochondria. I was running on fumes.
Now I understand what's actually happening at the cellular level, and I'm making changes. I'm not claiming I've mastered this – I'm very much on a path, working to improve. But understanding the science has completely changed my approach.
The key is this: not all fuels burn the same way in your mitochondria.
The Fat Burning Problem
Here's what I didn't understand during those high-stress, low-sleep years: when your body burns fat for fuel – especially under stress – it overloads your cellular machinery in a way that carbohydrates don't.
Bioenergetic researcher Georgi Dinkov explained this better than anyone I've found. Look for him on YouTube. He has an accent but you can make it.When you burn excessive amounts of fat, especially during chronic stress, your body drains a molecule called FAD. FAD is made from vitamin B2, and it's absolutely required for your mitochondria to process energy properly.
When FAD runs low, electrons back up in the energy chain. It's like a traffic jam on a highway – cars (electrons) can't move forward, so they start spilling off onto side roads (creating ROS). Your body's response? Force you into sleep to shut everything down and clean up the mess.
I used to see this with my long bike rides – we're talking ten, fifteen years ago now. I did a 100-mile ride in Savannah once. That was brutal. A painful ordeal I had no intention of repeating. But even on shorter rides of several hours, I'd come home completely wiped out, need a nap, and still sleep heavily that night.
I thought I was just working hard. Now I know I was flooding my system with fatty acids and creating massive electron leakage. My body needed all that sleep just to repair the damage.
The Serotonin Connection
There's another piece to this puzzle: serotonin.
Most people think of serotonin as the "happy" neurotransmitter. But it also makes you drowsy. When you burn a lot of fat, fatty acids accumulate in your blood. These fatty acids displace an amino acid called tryptophan from its carrier protein. More free tryptophan means more gets into your brain, where it converts to serotonin.
Higher serotonin equals more fatigue and stronger sleep pressure.
This explains why after a stressful day – when your body has been burning through fat stores – you feel completely exhausted even if you didn't physically exert yourself. Your brain is swimming in serotonin, and your mitochondria are leaking electrons like crazy.
Looking back, those 3 AM wake-ups with racing thoughts? That was probably cortisol trying to keep me functional despite my mitochondria being overwhelmed. Not a sustainable strategy.
What I'm Changing Now
Once I understood all this, I started making changes. I'm not perfect at this – I'm working on it, learning as I go. But here's what I'm doing:
1. Going to bed earlier and aiming for more sleep I used to stay up past 11 PM and accept whatever sleep I got. Now I'm in bed between 9 and 10 PM, aiming for a solid seven hours minimum. Some nights I hit it, some nights I don't. But the intention is there, and I'm tracking it with my Garmin Fenix. That body battery function is humbling. The algorithm is probably designed around eight hours of sleep. My goal is to consistently hit 100% – that's what truly restorative sleep looks like. I'm not there but I am continuing to improve. It's recognized more and more that good sleep is a major factor in health and well-being. I'm taking that seriously now in a way I didn't before.
2. Eating more carbohydrates This one surprised me. Carbs are supposedly the enemy, right? But here's the reality: carbohydrates are a cleaner fuel for your mitochondria. They produce less electron leakage than fat oxidation. Believe it or not but proteins require about 30% of the energy they create to manage the process of converting protein to energy. I'm eating healthy carbs now – fruit, vegetables, including potatoes and white rice. I may even use the dense carbohydrate energy source of honey. The goal is to give my cells steady, clean energy and reduce the toxic byproduct accumulation that drives sleep pressure. Metabolic flexibility is a term that implies switching around and using the various energy macromolecules (fat, carbohydrate and protein). The ability to switch back and forth efficiently gives us metabolic flexibility.
3. Moderate exercise, not extreme I haven't done those multi-hour endurance rides in over two decades, and I don't miss them. These days, my bike rides are about an hour, and I'm usually pushing zone 3 – that just feels like a good cadence for me. I know zone 2 is probably ideal for mitochondrial efficiency. It's just the pace I enjoy. I also get on the rowing machine several times a week for 30 to 45 minutes. I'm in high zone 2, low zone 3 for those sessions. The difference compared to those old endurance sessions is huge. I finish these workouts feeling energized, not depleted.
4. Using aspirin strategically Low-dose aspirin (I take about 100-150mg) several times a week helps lower free fatty acids in the blood and reduces serotonin. It's like unclogging a drain – energy flows more smoothly instead of backing up. I'm not recommending everyone take aspirin – definitely talk to your doctor – but for me, it's been helpful for managing daytime energy. Many report that it is especially effective about the time of that early afternoon drop in energy when you "just need a nap".
5. Timing carbs around activity After my morning workout, I make sure to eat fruit or another quick carb source. This prevents my body from shifting into heavy fat-burning mode when my cells need to recover. Your body is most efficient when it has the right fuel at the right time.
6. Focusing on mitochondrial efficiency The real goal isn't just more hours of sleep. It's having mitochondria that run cleanly enough that the sleep I do get is truly restorative. When cellular engines are efficient, they leak fewer electrons, create less toxic waste, and make better use of downtime.
The Seed Oil Problem
Here's something that's becoming clearer to me: one of the worst things you can do for mitochondrial health is eat seed oils.
Seed oils – soybean, canola, corn, sunflower, safflower – are loaded with linoleic acid. When you consume linoleic acid in the massive amounts found in the modern diet (it's in almost every processed food and restaurant meal), it gets incorporated into your mitochondria. Specifically, it becomes part of cardiolipin, a critical fat in the inner mitochondrial membrane.
The problem: linoleic acid is highly unstable. It oxidizes easily, creating toxic metabolites like 4-HNE (4-hydroxynonenal). These oxidized molecules damage your mitochondria directly, increase electron leakage, and make everything I just described worse.
Even worse, linoleic acid has a half-life of about two years in your body. That means it takes roughly six years to clear 95% of it out once you stop consuming it.
I eliminated seed oils from my diet years ago with the exception of some restaurant meals when I cheat and eat an item that likely has some seed oil fat component. I cook with butter, beef tallow, or coconut oil. I avoid restaurants that fry in vegetable oil (which is most of them). I read labels carefully.
This change probably has done more for my energy levels than anything else, but I'm still waiting for my body to fully clear out the linoleic acid I accumulated over decades. I'll be writing more about the seed oil problem in future articles – it connects to everything from obesity to heart disease to cancer.
The Bottom Line
Sleep isn't wasted time. It's your body's emergency repair protocol. How much you need is largely under your control, but it requires understanding what's actually happening at the cellular level.
I'm not claiming I've figured it all out. My Garmin Fenix reminds me every morning that I could do better. But I understand the mechanism now, and that changes everything.
When your mitochondria run efficiently – when you're burning clean fuel, managing stress, avoiding excessive exercise that depletes your system, and eliminating seed oils – you need less repair time. The sleep you do get becomes more restorative.
I'm 75 years old, and I'm still learning. Still experimenting. Still tracking my results and adjusting. That's what this journey looks like – not perfection, but steady progress based on understanding the science.
The research is clear: support your mitochondria with the right fuel (healthy carbs, not excessive fat burning), avoid extreme exercise that floods your system with fatty acids, eliminate seed oils from your diet, and your sleep quality improves naturally.
You might not hit 100% on your body battery right away. I haven't yet on a consistent basis. But imagine waking up after seven hours feeling truly refreshed. Imagine steady energy all day without relying on caffeine. Imagine your brain working clearly without afternoon fog.
That's what efficient mitochondria can give you.
The sleep you need is feedback about how cleanly you're running. Improve the engine, and the maintenance schedule takes care of itself.
I'm on that path. Based on what I'm learning, I think you can be too.