Brain Fog Starts in Your Feet (Scientifically Proven) : 1476

Summary

Podcast Summary: The Human Upgrade™ with Dave Asprey

Episode: Brain Fog Starts in Your Feet (Scientifically Proven) : 1476
Date: May 31, 2026
Host: Dave Asprey

---

Main Theme

In this episode, Dave Asprey explores a counterintuitive but scientifically supported cause of brain fog: poor foot mechanics and circulation. Dave shares his personal journey and distills cutting-edge insights on why brain fog often originates not in the mind, but in the body—specifically, in the feet. The episode weaves together research on circulation, sensory input, and movement, and provides actionable biohacks for cognitive clarity starting from the ground up.

---

Key Discussion Points & Insights

1. The Misdirection of Typical Brain Fog Solutions

[01:51–03:12]

• Dave reflects on his own decades-long struggle with brain fog and the frustration of not finding relief from usual biohacks like meditation, nootropics, or sleep optimization.
• Quote:
  "I lived with brain fog for 20 years. I couldn't think clearly, I couldn't focus, and words didn't come easily. I had a lot of work to do, so I tried everything better. Sleep, nootropics, cutting out caffeine, meditation, breathwork, red light, all the biohacks that you've heard about here. But none of them worked in isolation."
  — Dave Asprey [01:51]

2. The Critical Role of Circulation and Blood Flow

[03:12–05:36]

• The brain, despite its small size (2% of body weight), demands 20% of the body’s oxygen supply, making it highly sensitive to minor circulation drops.
• Poor blood flow—often stemming from sedentary lifestyles or weak foot/calf muscles—can deprive the brain of oxygen and glucose, leading to cognitive dullness.
• Dave likens it to "having a perfectly good engine, but you're running on half the fuel it needs."
• Quote:
  "If your brain doesn't get enough supply, it goes into conservation mode, which you feel as dullness, mental heaviness. It's not because you broke the engine—because it's just not getting the fuel it needs to run properly."
  — Dave Asprey [04:11]

3. How Foot Mechanics Affect the Brain

[05:36–07:21]

• Feet act as the body's furthest point from the heart and depend on muscle contraction for returning blood against gravity.
• Shoe choices and extended sitting weaken these muscles, leading to blood pooling in the legs and less oxygenated blood reaching the brain.
• Calves described as a "second heart," vital for pumping blood upward.
• Even a 10% reduction in brain blood flow can noticeably impair cognition.
• Quote:
  "Your calves work like a second heart. They squeeze blood upwards every time you walk. So when that pump stops working well, your circulation becomes sluggish and then your brain suffers."
  — Dave Asprey [05:58]

4. Sensory Feedback and Its Impact on Mental Clarity

[07:21–09:04]

• The foot is loaded with sensory neurons that provide the brain with continuous updates about balance and pressure.
• Modern cushioned shoes dull this feedback, resulting in subtle instability signals and heightened, low-level nervous system alertness.
• This constant "background tension" clouds thinking, even if there's no conscious stress.
• Quote:
  "It's not panic or anxiety. It's just low-level tension that clouds your thinking. Because your brain in the background is going, Where are my feet? Why can't I feel the floor?"
  — Dave Asprey [08:00]

5. Grounding, Barefoot Walking, and Nervous System Balance

[09:04–11:05]

• Walking barefoot on varied, natural surfaces instantly enriches foot sensory input, grounding the body and calming the nervous system.
• Strengthening foot muscles helps realign the whole movement chain, lessening bodily tension and promoting richer sensory data to the brain.
• Quote:
  "Walk barefoot whenever you can. Grass, sand, uneven surfaces. That's going to wake up the sensors in your feet and restore sensory feedback. And varied terrain forces your feet to adapt and adjust constantly. That turns on muscles and sensors that may have been dormant for a long time."
  — Dave Asprey [10:00]

6. Practical Biohacks for Brain Clarity

[11:05–12:39]

• Dave offers direct interventions:
  • Walk barefoot regularly
  • Use minimal shoes instead of cushioned ones
  • Perform exercises like toe spreading, picking up objects with feet, and balance drills
  • Engage in calf raises and uphill walking to stimulate the lower limb "pump"
• He insists these foundational practices made the biggest difference in his own recovery from brain fog.
• Quote:
  "I spent 20 years trying to fix brain fog from the top down... But none of it works completely. Until I realized the problem wasn't in my head. It was in my feet. Once I started walking barefoot, strengthening my feet and letting them work the way they're designed to, the fog lifted."
  — Dave Asprey [11:34]

---

Memorable Moments & Quotes

• On circulation:
  "Subtle reductions hit hard enough. Brain fog feels like mental tiredness, but it's actually your cells running low on oxygen." [04:51]
• On foot mechanics as biohacking:
  "Cushion shoes work like sensory deprivation chambers for your feet. And minimal shoes or barefoot walking restores the connection between your feet and your brain." [11:12]
• Closing insight:
  "If you've been dealing with brain fog and nothing works, look down. Your feet might be the problem. Start walking barefoot when you can, start strengthening your feet with simple exercises. Let them feel the ground again. Your brain will thank you." [12:20]

---

Timestamps for Major Segments

• [01:51] – Dave’s experience with persistent brain fog and failed interventions
• [03:12] – Blood flow and cognitive function: why your brain needs optimal circulation
• [05:36] – The mechanics of foot/calf muscles and their role in returning blood to the brain
• [07:21] – The importance of sensory input from feet to the brain
• [09:04] – Grounding, barefoot walking, and the link to improved mental clarity
• [11:05] – Practical foot and calf exercises as foundational brain biohacks
• [12:20] – Summary and call-to-action

---

Overall Tone & Style

Dave’s delivery is passionate, practical, and personal—blending his own struggles and triumphs with clear science. The episode is encouraging to listeners, demystifying brain fog and empowering them to look “below the neck” for cognitive solutions.

---

Takeaway

If cognitive sluggishness persists despite all the usual biohacks, “look down.” Weak feet and poor circulation may be blocking your brain's performance. Building foot and calf strength, going barefoot, and restoring sensory feedback could be the missing foundation for your mental upgrade.

Transcript

[A]

You can be health conscious, doing everything right, and still feel like garbage. And the reason is almost always the same. Mineral deficiency. And not because you're not trying. Because modern soil is depleted, crops today have up to 40% fewer minerals than they did 50 years ago. Your food isn't what it used to be. But here's the part nobody talks about. Nutrients don't work in isolation. Minerals and fat soluble vitamins D, A, K and E work together in your body. Vitamin D helps your body absorb calcium. K2 makes sure calcium goes into your bones, not your arteries. You need magnesium to activate vitamin D so your body can use it. Without these nutrients present together, your system doesn't run efficiently. You might as well flush money down the toilet. That's exactly why I created dake and minerals 101D, 3A, K2E and a full mineral stack designed to work together. Because that's the only way any of it actually works. Cold plunges, red light, sauna, you can do it all. But none of it matters if your foundation is broken. Fix the foundation. Grab your Dake and Minerals 101 [e-mail] and use code DAVEPOD for 15% off today.

[B]

And Doug, there's nowhere I wouldn't go to help someone customize and save on insurance with Liberty Mutual. Even if it means sitting front row at a comedy show.

[C]

Hey, everyone. Check out this guy and his bird. What is this, your first date?

[B]

Oh, no. We help people customize and save on car insurance with Liberty Mutual together. We're married. Me to a human, him to a bird.

[C]

Yeah, the bird looks out of your league.

[B]

Anyways, get a [e-mail] or with your local agent.

[D]

Liberty. Liberty. Liberty. Liberty.

[C]

I lived with brain fog for 20 years. I couldn't think clearly, I couldn't focus, and words didn't come easily. I had a lot of work to do, so I tried everything better. Sleep, nootropics, cutting out, caffeine, meditation, breathwork, red light, all the biohacks that you've heard about here. But none of them worked in isolation. One of the variables that I didn't understand was that I needed to learn to walk Again, not physically walk, I could already do that, but actually use my feet the way they're supposed to work. And it helped to change brain fog. And brain fog doesn't always start in your head, it can start in your feet. So you might wake up foggy and think, what's wrong with me? It must be the sleep. It must be the stress. Maybe it's just getting old. You assume your brain's broken. Maybe something's wrong with your thinking. Maybe you need to try harder, focus more. You can get more sleep, maybe take some supplements. Or maybe you're just not as smart as you thought you were. But very few people ask if the problem comes from somewhere else, somewhere outside your skull. Your brain needs a massive amount of oxygen and glucose to function, more than almost any other organ. For its size, that means it's super sensitive to even small drops in blood flow. Your body, it's a connected system. Blood moves through it like water moves through pipes. And if there's a kink anywhere in the line, something downstream suffers. If your brain doesn't get enough supply, it goes into conservation mode, which you feel as dullness, mental heaviness. Just can't think sharply even when you're really trying. Here's what most people don't realize. Your brain might work perfectly fine Structurally, your neurons all function, all the connections are intact. But if blood flow drops even a little bit, your your thinking crashes. It's like having a perfectly good engine, but you're running on half the fuel it needs. Everything's going to slow down. It's not because you broke the engine, because it's just not getting the fuel it needs to run properly. Brain fog starts below your head long before you notice it in your thoughts. It may not be a problem in your brain. It can be about whether your brain's even getting what it needs to work to fix what's happening at the top. You look at the base. The brain uses about 20% of your body's total oxygen supply, and it only makes up 2% of your body weight. So it's a massive demand. It means even minor circulation issues are going to create cognitive effects. And most people never connect foggy thinking to a sedentary lifestyle or tight shoes. But the connection's direct and measurable. Poor circulation starts at the extremities, and your feet are the furthest from your heart, and they have the most gravity working against them. Your feet rely on muscle squeezes to push blood back up against gravity. But when you sit all day, those muscles get weak and tight. Shoes and stiff soles that restrict your feet move will mess up how your body pumps blood up through the legs. When that muscular pump in your calves weakens, blood pools in your legs instead of flowing back into your heart. That means less oxygenated blood is going to reach your brain. Your calves work like a second heart. They squeeze blood upwards every time you walk. So when that pump Stops working well, your circulation becomes sluggish and then your brain suffers. The important thing to know is even small drops in blood flow to your brain mess with your attention span and even your reaction time in studies. Those studies show that reducing blood flow to the brain by just 10% can significantly, significantly hurt how well you think. You don't need a major circulation problem to feel the effects. Subtle reductions hit hard enough. Brain fog feels like mental tiredness, but it's actually your cells running low on oxygen. It's like trying to run that engine on fumes. Engine works fine, it's just not getting the fuel. When you restore strength and movement in your feet and calves, that blood flow improves. From the ground up, the pump starts working again. Circulation goes up, and then more oxygenated blood gets into your brain. The venous system in your legs relies almost entirely on muscle contraction the to move blood upwards. And if you're not doing regular calf activation, that blood sits in your lower extremities. It's called blood pooling. And that reduces the amount of blood available for your brain. That's why people who sit for eight hours a day can just get that afternoon brain fog. It might be blood sugar, it might also be blood flow. It's because their calf pump has been inactive all day and their brain is suffering as a result. Circulation tells only half the story. Cuz your feet also rank as one of the biggest sensory input zones in your body. There's thousands of tiny sensors in your souls and send constant updates to your brain about pressure and balance. Where's the ground? And that feedback helps your brain control your posture, your stability, and even how your nervous system's working. Modern squishy cushion shoes kill most of that feedback. They're muffling the signals. So when sensory input drops, your brain gets less information about where your body exists in space. That creates subtle instability signals that put your nervous system on just a little bit more alert. It's not panic or anxiety, it's just low level tension that clouds your thinking. Because your brain in the background is going, where are my feet? Why can't I feel the floor? Your brain needs stable feedback to stay calm and balanced. When that feedback is inconsistent, your nervous system compensates. It's trying to pay more attention, more alert, more ready for threats. Which means you're not as ready for thinking. That shifts blood flow away from parts of your brain responsible for focus and planning and decision making. And instead it goes to survival circuits. And think about it this way. Your brain is constantly receiving signals from your feet about Whether you're stable or unstable, safe or unsafe, grounded or unsteady, when those signals come through clear and consistently, your brain can stay relaxed. But if the signals are muffled or inconsistent, your brain interprets that as potential danger. And it turns on stress responses and more alertness of things you don't want to be focusing on. You're not stressed, but your body acts like you are. And that low level activation could run in the background for years without even noticing. But it is slowly killing your clarity. Brain fog isn't always mental tiredness. Sometimes your nervous system misfires because your feet aren't giving your brain the information it needed to stay calm and focused. The signals your feet send to your brain help keep your nervous system balanced. Clear signals keep you calm and focused. And unclear ones can stress your body out and mess with your thinking. This is why walking barefoot on natural surfaces often produces immediate improvements in mental clarity. That sensory richness calms your nervous system within minutes. And it keeps your brain connected to the earth. When your feet grow strong and mobile and send clear signals, everything stabilizes. Strong foot muscles improve how your body aligns. And that means that you have less tension in your muscles. When you can activate your calves better, it pushes more blood back to your heart and your brain. And that clear sensory input from your feet is going to calm your nervous system down. More oxygen and more glucose reach your brain tissue. Your nervous system shifts from watchfulness to balance. And your brain processes information faster because it's getting a steady supply and clear signals. Your brain will only let you focus when it has those things clear turns. Not because you fixed your brain directly, but because you restored the foundation that supports it. Walk barefoot whenever you can. Grass, sand, uneven surfaces. That's going to wake up the sensors in your feet and restore sensory feedback. And varied terrain forces your feet to adapt and adjust constantly. That turns on muscles and sensors that may have been dormant for a long time. And your brain starts receiving rich detail, detailed info about your environment again. And your brain really likes that. You strengthen your feet by spreading your toes, picking things up with your feet, balancing on one foot like I am right now. These are movements that turn on the small muscles that have slept for years in rigid shoes.

[E]

You spend a third of your life in bed. If you're sleeping on a toxic mattress, you're sacrificing quality sleep and recovery. Bad sleep isn't just about feeling tired. It weakens your immune system, raises inflammation and accelerates, accelerates aging. I don't risk that. I use an essentia mattress. I've been sleeping on an Essentia for years. And that's why I teamed up with them to create the Dave Asprey upgrade, an enhanced EMF protection upgrade built right into their performance mattresses. This is next level biohacking for your sleep. Protecting your body from emfs, delivering outrageously comfortable beyond latex organic foam that outperforms memory foam. And doing it all without petrochemicals or chemical flame retardants. The Essentia team designed this to help you spend more time in those crucial REM and deep sleep cycles so your body and brain can perform at their peak. This mattress works. I've tracked it. If you care about recovery, cognitive function and longevity, your mattress is one of the biggest upgrades you can make. Just go to myessentia.com Dave and use code Dave for $100 off to experience the upgrade for yourself.

[F]

Your hair is a sign of how healthy you are. So what actually works?

[C]

If you want to grow new hair,

[F]

there are tons of products that sound good on paper, but they really don't do much in practice. Irestore is different because it is powerful and it's targeted and it's light therapy. Your hair follicles directly absorb the light energy, which means blood flow increases and that means dormant hair follicles can wake back up. The Elite delivers that through 300 lasers and 200 LEDs directly to your scalp. And it takes an easy 12 minutes a day. And you can wear it while you're working, while you're doing chores around the house. And the clinical results from it are amazing. Double blind study. 100% of participants grew more hair. In four months, their hair count increased an average of 43.2%. And this thing really works. Plus you get a 12 month money back guarantee.

[C]

Try it for a year and see

[F]

what happens and you'll like it. Spring savings is happening right now, so go to irestore.com use code Dave and get an exclusive discount on the elite. Elite, that's irestore.com code Dave

[C]

and those small foot muscles exist to stabilize and control fine movements. And when they're weak, your entire movement chain suffers. When they're strong, everything above them works better. Ditch the cushion soles whenever possible and go minimal so your feet can feel the ground. Because the more information your feet send to your brain, the better your brain can control itself. Cushion shoes work like sensory deprivation chambers for your feet. And minimal shoes or barefoot walking restores the connection between your feet and your brain. Turn on your calves through calf raises, walking uphill or anything that works that secondary pump that improves blood return and gets more oxygen to your brain. Think of your calves as a pump for your brain. Every time they squeeze, they push blood upwards against gravity the same way your heart does. So strengthening your calves means better circulation throughout your entire body, including your brain. I spent 20 years trying to fix brain fog from the top down, with better sleep, nootropics, meditation, diet changes, and all of it helps. But none of it works completely. Until I realized the problem wasn't in my head. It was in my feet. Once I started walking barefoot, strengthening my feet and letting them work the way they're designed to, the fog lifted. It was not overnight, but within weeks I noticed the difference. My thinking got sharper, my words came easier, my focus lasted longer, and to this day, I wear minimal footwear for a reason. If you've been dealing with brain fog and nothing works, look down. Your feet might be the problem. Start walking barefoot when you can, start strengthening your feet with simple exercises. Let them feel the ground again. Your brain will thank you.

[D]

A Human Upgrade Formerly Bulletproof Radio was created and is hosted by Dave Asprey. The information contained in this podcast is provided for informational purposes only and is not intended for the purposes of diagnosing, treating, curing, or preventing any disease. Before using any products referenced on the podcast, consult with your healthcare provider carefully read all labels and heed all directions and cautions that accompany the products. Information found or received through the podcast should not be used in place of a consultation or advice from a healthcare provider. If you suspect you have a medical problem or should you have any healthcare questions, please promptly call or see your healthcare provider. This podcast, including Dave Asprey and the producers, disclaim responsibility for any possible adverse effects from the use of information contained herein. Opinions of guests are their own and this podcast does not endorse or accept responsibility for statements made by guests. This podcast does not make any representations or warranties about guest qualifications or credibility. This podcast may contain paid endorsements and advertisements for products or services. Individuals on this podcast may have a direct or indirect financial interest in products or services referred to herein. This podcast is owned by Bulletproof Media.