The Matt Walker Podcast

In this latest AMA episode, Matt and Dr. Eti Ben Simon explore the complex web connecting sleep to our health and daily lives. They investigate the gut-brain axis, discussing how sleep deprivation alters the microbiome and whether probiotics can restore balance. The conversation also addresses the heavy toll of bereavement, examining the bidirectional link between acute grief and insomnia while offering evidence-based strategies to manage sleep during times of loss. The discussion shifts to c...

Transcribed - Published: 8 December 2025

Matt confronts the systemic failure of sleep deprivation, examining its impact on our biological machinery. When sleep is short, the body's "fuel gauge" dips, impairing mitochondrial function and glucose tolerance. However, he highlights compelling research on two interventions - creatine supplementation and high-intensity interval training. These act as backup generators, offering a physiological buffer to preserve metabolic and executive functions when rest is unavoidably restricted. The ep...

Transcribed - Published: 1 December 2025

Matt ventures into the realm of 40 Hz "gamma" rhythms - the conductor of the biological orchestra during high-order cognition - to explore how non-invasive light and sound stimulation can entrain brain activity, nudging neurons into synchrony. Crucially, Matt examines ground-breaking Alzheimer’s research where this rhythm rallies the brain's immune cells to clear toxic plaques, potentially stabilizing memory and preventing atrophy in early-stage patients. Beyond cognition, Matt uncovers a neu...

Transcribed - Published: 24 November 2025

The counterintuitive use of sleep deprivation as a rapid treatment for major depression finds itself squarely in Matt’s spotlight today. He begins by discussing its origins in the 1970s, where one night of wakefulness induced temporary remission in 40-60% of patients, and goes on to note that this effect is fragile, with an 83% relapse rate after recovery sleep, pointing to a paradox where sleep itself may be depressogenic for some. Matt reviews the neuroscientific explanations, including the...

Transcribed - Published: 17 November 2025

Matt delves into Heart Rate Variability (HRV), the subtle variation in timing between each heartbeat. He explains that a healthy heart is like a "jazz drummer," not a rigid metronome, and a higher HRV reflects a resilient body that can adeptly balance its stress and rest systems. This episode unpacks the science behind HRV and explores the actionable strategies you can employ to improve this critical marker of your overall health. Matt then explores the key lifestyle factors that significantl...

Transcribed - Published: 10 November 2025

Diving into the controversial world of Modafinil, the "all-nighter in a pill", Matt begins with the story of Olympic sprinters using the narcolepsy drug as a loophole for a competitive edge. He then unpacks the science of how Modafinil affects brain chemistry to boost wakefulness and cognition, tracing its evolution from a medical treatment to a performance enhancer for the military, Wall Street, and students, all attempting to push human limits by cheating sleep. Despite its potent effects, ...

Transcribed - Published: 3 November 2025

Matt explores the fascinating world of synesthesia today, challenging the notion that it's a rare quirk by proposing a bold claim: in subtle ways, we are all synesthetes. This idea is powerfully demonstrated by the famous "Bouba/Kiki" test, which reveals our brain's innate tendency to connect abstract shapes and sounds. The episode argues that this fundamental cross-wiring is not a mere curiosity but the very operating system for human thought, shaping everything from our metaphors to the dev...

Transcribed - Published: 27 October 2025

Framing sleep not as a biological necessity, but as a critical economic asset, Matt reveals that sleep deprivation costs the U.S. economy up to $411 billion annually, with billions more lost globally. These costs stem from lost workplace productivity, severe cognitive impairment equivalent to intoxication, and massive strains on healthcare and public safety systems due to chronic disease and accidents like drowsy driving. Matt provides the solution: investing in sleep as a powerful economic s...

Transcribed - Published: 20 October 2025

In this user's guide to sleep trackers, learn the science behind how they work using motion and optical sensors as Matt explains the key metrics of Sensitivity, Specificity, and Accuracy. Revealing why most trackers overestimate sleep by failing to detect wakefulness, he reveals the crucial difference between a device's flawed "absolute accuracy" and its more valuable "relative accuracy," which highlights the importance of tracking long-term trends over single-night scores. Matt goes on to ex...

Transcribed - Published: 13 October 2025

Matt takes a deep dive into REM sleep this week, highlighting methods to enhance this vital stage for emotional regulation and creativity. Detailing pharmacological approaches, he focuses on the neurotransmitter acetylcholine and how medications like donepezil and modern DORAs can boost REM sleep, while also identifying common suppressors like alcohol and THC. Throughout the episode, he also emphasizes that the goal is not to maximize one stage but to achieve a balanced sleep architecture. Th...

Transcribed - Published: 6 October 2025

In this soothing episode, Matt guides you on your personal sleep story towards deep, restorative rest. He invites you to find comfort and release the day's worries through intentional breathing, transporting you to a cozy, imagined haven bathed in soft lights and calming aromas. As twilight descends, experience the tranquil silence and the moon's gentle glow, replacing any turmoil with profound inner peace. A powerful visualization encourages you to shed thoughts and concerns, picturing them ...

Transcribed - Published: 29 September 2025

In this week’s episode, Matt Walker explores memory's astonishing malleability, challenging the belief that recollections are fixed. He highlights Loftus's car crash study, showing how subtle language altered speed memories and implanted false details, and reviews the "Lost in the Mall" experiment which proved fabricated autobiographical memories can be instilled. Matt also notes that neuroimaging reveals false and true memory patterns in the hippocampus are remarkably similar, underscoring m...

Transcribed - Published: 22 September 2025

Founder & CEO of Elevated Medical, Dr. Avinish Reddy, joins Matt today on this very special episode to discuss a comprehensive approach to longevity. One core theme presented is the profound interconnectedness of physical, mental, and cognitive well-being, essential for true health optimization. Dr. Reddy emphasizes the striking impact of social connection: isolation can increase early death risk by 50%, comparable to smoking. He believes fostering strong social bonds is a fundamental pil...

Transcribed - Published: 15 September 2025

In this latest AMA instalment, Matt and Dr. Eti Ben Simon begin by discussing environmental influences on sleep. The conversation covers how high latitude and prolonged daylight disrupt circadian rhythms, with Eti sharing her own personal experience. Together, our duo shares strategies for managing light exposure and regulating core body temperature with methods like warm baths. The episode also offers evidence-based approaches for shift workers, including strategic napping and forward-rotati...

Transcribed - Published: 8 September 2025

Matt explores the critical link between sleep and Alzheimer's disease today, explaining how the brain’s "glymphatic system" clears toxic proteins like amyloid and tau during deep sleep. He describes how insufficient sleep impairs this process, creating a vicious cycle where protein accumulation damages sleep-generating brain regions and increases dementia risk. Matt goes on to discuss groundbreaking research on a new class of sleeping pills, Dual Orexin Receptor Antagonists (DORAs), that may ...

Transcribed - Published: 1 September 2025

Matt and Dr. Eti Ben Simon join forces once again to answer all of your top sleep questions. This time around, they break down the science behind the snooze button, why you might be falling asleep during passive activities like watching TV, and the truth about sleep fads like consuming salt before bed or using "grounding sheets." The episode also explores the frustrating issue of sleep fragmentation - waking up multiple times a night - and why it undermines sleep quality even if you fall back...

Transcribed - Published: 25 August 2025

In this episode, Matt delves into the curious and cautionary tale of Delta Sleep-Inducing Peptide (DSIP), once hailed as a potential miracle cure for insomnia. In the 1970s, researchers were on a quest for a single "somnogenic molecule" that could act as the brain's natural sleep switch. A Swiss team believed they had found it, isolating a peptide that appeared to rapidly induce deep, slow-wave sleep when injected into animals. This initial excitement led to bold claims and sparked decades of...

Transcribed - Published: 18 August 2025

Matt explores the human capacity for echolocation this week, dismantling the myth that this "biological sonar" is exclusive to animals. Revealing how peer-reviewed research shows all human brains possess the neural hardware to "see" with sound, Matt explains the physics of how sound creates detailed acoustic maps of our environment and introduces the brain's remarkable plasticity, setting the stage for this incredible sensory adaptation. The episode features stories of pioneers like Daniel Ki...

Transcribed - Published: 11 August 2025

While we've long been told to focus on the quantity of our sleep, in today’s episode, Matt suggests a paradigm shift in our understanding of sleep health. He argues that the true cornerstone may not be how many hours we get, but the consistency of our sleep schedule. This concept of regularity - maintaining a stable bedtime and wake-time - is presented as the most impactful of four key sleep components, which also include the more familiar aspects of quantity, quality, and timing. Matt suppor...

Transcribed - Published: 4 August 2025

Settle in for a deeply comforting experience as Matt returns with a gentle voyage aboard "The Dreamer." This sleep story is crafted to soothe the heart and quiet the mind, creating a perfect sanctuary for rest. Tonight, we journey to a peaceful, seaside village to meet Henry, an elderly widower whose sleepless nights are filled with a profound sense of loss and treasured memories of his late wife, Margaret. As Henry steps onto the boat, feeling the weight of his grief begin to soften wi...

Transcribed - Published: 28 July 2025

This week, Matt examines the viral trend of mouth taping, a practice touted as a remedy for snoring and sleep apnea. He explains the core theory, which centers on promoting the benefits of nasal over mouth breathing, before critically assessing whether this popular ritual is a scientifically sound solution or a risky trend whose dangers are lost amidst the online hype. Matt navigates the scientific evidence, revealing a cautionary tale: while preliminary data suggests a potential benefit for ...

Transcribed - Published: 21 July 2025

In their latest Ask Me Anything episode, Matt and Dr. Eti Ben Simon delve into the complex relationship between common substances and sleep. They first tackle cannabis, explaining that while THC may initially help with sleep onset, its chronic use is detrimental, leading to tolerance, withdrawal insomnia, and a powerful suppression of restorative REM sleep. The discussion then moves to two other major sleep disruptors: caffeine and alcohol. You'll learn how caffeine's long half-life can reduc...

Transcribed - Published: 14 July 2025

Matt welcomes UCSF sleep expert Dr. Aric Prather to the podcast this week to discuss the science of psychoneuroimmunology: the link between our behavior and immune health. After a primer on the immune system’s innate and adaptive arms, Dr. Prather details how insufficient sleep dramatically increases your risk of catching a cold, significantly blunts vaccine effectiveness by reducing antibody response, and promotes a state of chronic, low-grade inflammation - a known pathway to numerous age-r...

Transcribed - Published: 7 July 2025

Prepare for a tranquil journey into sleep as Matt returns with a voyage aboard "The Dreamer." Let go of the day's events and allow your mind to quiet as we travel to a busy coastal town. Tonight, you’ll meet Sophia, a painter whose vibrant and expressive works reflect the world around her, yet finds her own nights restless and her mind unable to settle. Her creativity is blocked and her thoughts race, keeping peaceful sleep just out of reach. Just as she sits by her window, watching the waves...

Transcribed - Published: 23 June 2025

Matt delves into the science of "beauty sleep" this week, revealing it as somewhat of a scientific reality. He highlights research by Dr. Tina Sundelin, which demonstrates that sleep-deprived individuals are consistently perceived as less healthy, more fatigued, and less attractive. These visible changes are rooted in biological consequences like dilated under-eye blood vessels and elevated cortisol, a hormone that degrades vital skin collagen. Matt then differentiates between expression wrin...

Transcribed - Published: 16 June 2025

Dr. Eti Ben Simon returns for yet another AMA episode, this time specifically focussing on sleep and women. Together, they delve into the nuanced differences in sleep patterns between men and women, exploring aspects like sleep duration, quality, and architecture, including variations in deep sleep and REM sleep. They discuss how females generally sleep slightly longer, experience fewer awakenings, and have more deep sleep early in the night, alongside a quicker onset of REM sleep. The conver...

Transcribed - Published: 9 June 2025

Sleep expert Dr. Aric Prather joins Matt today for a fascinating discussion about insomnia's frustrating reality: trying to force sleep backfires; sleep arrives naturally. Dr. Prather highlights a surprising starting point: forget focusing on bedtime, prioritize a consistent wake-up time, even weekends. Noting that this anchors your internal clock and builds essential sleep pressure (the 'balloon'), he also cautions that sleeping in after a bad night disrupts this cycle. After touching ...

Transcribed - Published: 2 June 2025

Drift into tranquility tonight as Matt pilots your voyage to a deeply restful slumber in this calming sleep narrative. Prepare to release the day's hold and find solace on a serene sea, where the rhythm of the waves and the canopy of stars invite peaceful repose. Picture yourself embraced by the gentle motion of the water, the day's warmth slowly giving way to the cool embrace of a twilight sky, speckled with distant, shimmering lights. You will encounter "The Dreamer," a special vessel with ...

Transcribed - Published: 26 May 2025

Matt delves into the science of weighted blankets for sleep improvement in this week’s episode. These heavy covers (10-40 lbs) utilize Deep Pressure Stimulation (DPS), a concept originating from Dr. Temple Grandin's 1960s work. DPS is theorized to shift the nervous system from "fight-or-flight" to a calmer parasympathetic state by potentially increasing serotonin and activating brain regions involved in emotional regulation, like the insular cortex, thereby fostering a state conducive to slee...

Transcribed - Published: 19 May 2025

Matt and Dr. Eti Ben Simone are back again today to answer even more of your brilliant sleep questions! They begin by discussing smartphones, noting that the direct EMF impact on brainwaves is debatable, but that psychological activation and blue light are known disruptors. Moving onto naps, Matt explains longer ones can cause "sleep inertia," while short naps (20 mins) can be beneficial, unless insomnia is present. They then examine the full moon's debated effect on sleep, and how it is poss...

Transcribed - Published: 12 May 2025

Matt takes the opportunity this week to explore the perplexing sleep phenomenon of night terrors (sleep terrors). Matt clarifies that these are distinct from nightmares, defining them as parasomnias arising from abrupt arousals out of deep Non-REM sleep, not REM sleep where dreaming occurs. He details the often dramatic symptoms – intense fear, screaming, sweating, rapid breathing, confusion, sometimes thrashing or sleepwalking – emphasizing the typical lack of memory of the event afterward. ...

Transcribed - Published: 5 May 2025

Matt takes the opportunity this week to explore the perplexing sleep phenomenon of night terrors (sleep terrors). Matt clarifies that these are distinct from nightmares, defining them as parasomnias arising from abrupt arousals out of deep Non-REM sleep, not REM sleep where dreaming occurs. He details the often dramatic symptoms – intense fear, screaming, sweating, rapid breathing, confusion, sometimes thrashing or sleepwalking – emphasizing the typical lack of memory of the event afterward. ...

Transcribed - Published: 5 May 2025

Embark on a celestial journey tonight as Matt guides you through the vast expanse of the night sky in this soothing sleep story. Prepare to travel amongst the stars, exploring the constellations that have captivated humanity for millennia. Imagine yourself lying comfortably beneath the heavens on a warm evening, the stars twinkling like distant fireflies. Feel the gentle night air as you connect with the awe and wonder felt by ancient civilizations who gazed upon these same cosmic patterns, w...

Transcribed - Published: 28 April 2025

This week, Matt dismantles the myth that REM sleep only benefits the mind by revealing its profound importance for physical health. While deep sleep handles some repair, Matt details how REM is crucial for peak testosterone and growth hormone release, vital for muscle, bone, libido, tissue repair, and metabolism. He explains that REM's characteristic muscle paralysis (atonia) isn't just for safety; it fosters physical recovery by enabling deep muscle relaxation, boosting blood flow, lowering ...

Transcribed - Published: 21 April 2025

In this latest AMA episode, Matt and Dr. Eti Ben Simon tackle even more listener questions regarding any and all aspects of sleep. Today, they discuss sleep tracker accuracy, noting that while nightly data isn't perfect (~75-85% accurate), weekly trends are reliable. Feeling exhausted despite good tracker metrics? Potential causes include fragmented sleep, circadian issues, undiagnosed disorders (like apnea), or tracker-induced anxiety (orthosomnia). Matt and Eti stress consulting a specialis...

Transcribed - Published: 14 April 2025

Dr. Cheri Mah returns to the podcast today to explore a few different topics including how circadian rhythms shape athletic performance. She notes that these 24-hour cycles regulate sleep, hormones, and core temperature, with peak physical capacity often occurring between 4-8 pm—when many world records are set. Dr. Mah also discusses chronotypes, showing how tailoring training to one’s natural rhythm can enhance results. She reveals research on circadian disruption in sports, notably ho...

Transcribed - Published: 7 April 2025

Find tranquility in a secret setting as Matt guides you through tonight's sleep story set in "The Twilight Garden." Meet Clara, the lamp keeper, who lovingly tends to the hundreds of lanterns that illuminate this hidden haven. On this particular evening, a grieving visitor arrives, seeking solace and a way to remember a lost loved one. As Clara shares the garden's quiet magic and the healing power of light, you'll be enveloped in the garden's peaceful atmosphere, filled with the scent of lave...

Transcribed - Published: 24 March 2025

In today’s episode, Matt challenges the notion that REM sleep is solely for the brain, revealing its broad impact on physical health. He delves into REM's role in regulating testosterone and growth hormone, crucial for muscle function. Our host also highlights how REM aids muscle recovery via paralysis, boosting blood flow and supporting protein synthesis. Beyond muscles, Matt explores REM's effects on temperature regulation and heart health by boosting heart rate variability and promoting st...

Transcribed - Published: 17 March 2025

Matt and Dr. Eti Ben Simon team up to answer more audience questions today, and begin by delving into the subjective experience of time during dreams, exploring how our perception stretches and compresses during REM sleep and whether we can hack our dreams. They also explain the cognitive, emotional, hormonal, and immunological consequences of pulling an all-nighter, highlighting the dramatic impact on memory consolidation, stress hormones, appetite regulation, and immune function. The cardio...

Transcribed - Published: 10 March 2025

Matt and Dr. Eti Ben Simon team up to answer more audience questions today, and begin by delving into the subjective experience of time during dreams, exploring how our perception stretches and compresses during REM sleep and whether we can hack our dreams. They also explain the cognitive, emotional, hormonal, and immunological consequences of pulling an all-nighter, highlighting the dramatic impact on memory consolidation, stress hormones, appetite regulation, and immune function. The cardio...

Transcribed - Published: 10 March 2025

Matt Walker welcomes Dr. Ranji Varghese back to the podcast today to complete the whole sleeping pill story by discussing newer sleeping pills, beyond benzos and Z-drugs. Together, they explore Melatonin receptor agonists (like Ramelteon) that signal sleep preparation, unlike sedating GABAergics. They also detail how DORAs inhibit the wakefulness-promoting orexin, how off-label options (ex. trazodone, low-dose doxepin) affect histamine, the risks and benefits of each. Dr. Varghese goes ...

Transcribed - Published: 3 March 2025

Escape into a world of untold stories with Matt as he guides you through tonight's sleep story set in "The Archive of Lost Letters." Meet Stephanie, the archivist, who tends to letters never sent, filled with unspoken confessions and unshared truths. Tonight, a visitor arrives, searching for a lost piece of himself. As Stephanie helps him uncover a forgotten letter, you'll be enveloped in the library's quiet atmosphere, filled with the scent of old parchment and the weight of unspoken words. ...

Transcribed - Published: 24 February 2025

This week Matt explores dreams, questioning if their specific content matters beyond the normal benefits of REM sleep. This episode examines dreaming's significance for creativity, memory integration, and its role as emotional first aid. The discussion then introduces a "hot off the press" study showing how dreams might help us shed unwanted memories, with insights into how REM sleep acts as a nocturnal soothing balm for emotional distress. The episode shares how REM sleep can take the ...

Transcribed - Published: 17 February 2025

In their latest AMA episode, Matt and Eti address listener questions ranging from "beauty sleep" to 3 AM awakenings. They explore the scientific evidence supporting sleep's crucial role in skin health and perceived attractiveness, citing studies on the effects of sleep deprivation. The cognitive benefits of napping are discussed, highlighting its ability to enhance learning and memory consolidation. They also delve into the remarkable neural activity of deep non-REM sleep, including synchroni...

Transcribed - Published: 10 February 2025

This week, Matt Walker dives into the world of the widely used sleeping pill, Ambien (Zolpidem). He explains how Ambien, a non-benzodiazepine sedative-hypnotic, works by targeting the brain's GABA receptors, specifically the alpha-1 subunit, to induce sleep. However, this comes with consequences. Matt highlights research by Dr. Marcos Frank showing that Ambien significantly impairs memory consolidation, essentially unwiring the brain's learning processes during sleep by approximately 50%.&nbs...

Transcribed - Published: 3 February 2025

This week, Matt Walker dives into the world of the widely used sleeping pill, Ambien (Zolpidem). He explains how Ambien, a non-benzodiazepine sedative-hypnotic, works by targeting the brain's GABA receptors, specifically the alpha-1 subunit, to induce sleep. However, this comes with consequences. Matt highlights research by Dr. Marcos Frank showing that Ambien significantly impairs memory consolidation, essentially unwiring the brain's learning processes during sleep by approximately 50%.&nbs...

Transcribed - Published: 3 February 2025

Settle into the embrace of your bed, feeling its comforting presence beneath you. This connection anchors you to the present, quieting the mind's chatter and creating a foundation for restful sleep. Tired of untrustworthy protein shakes? Show sponsor Puori prioritizes quality: hormone-free, GMO-free, and pesticide-free. Every batch is third-party tested for 200+ contaminants - you can even scan the QR code for lab results! Matt recommends the addictive dark chocolate flavor with 21g of p...

Transcribed - Published: 27 January 2025

Join Matt and renowned sleep scientist Dr. Cheri Mah today as they delve into the crucial connection between sleep and athletic performance. Dr. Mah's groundbreaking research at Stanford, including her famous basketball player sleep extension study (which revealed a 9% improvement in free throws and three-pointers!), demonstrates how prioritizing sleep can significantly enhance athletic abilities. In this fascinating episode, she discusses with Matt how sleep impacts not only physical recover...

Transcribed - Published: 20 January 2025

In his latest "Ask Me Anything" episode, Matt is once again joined by Dr. Eti Ben Simon to respond to a variety of audience questions, beginning with the role of AI in sleep medicine. Together, they explore how AI is currently being used to improve the accuracy and efficiency of sleep stage scoring, and how it shows promise in diagnosing sleep apnea and personalizing treatment plans. Matt highlights the potential for AI to integrate with smart home technology and predict an individual's risk ...

Transcribed - Published: 13 January 2025

Welcome back to a new episode of the Matt Walker Podcast, where we revisit the often-discussed topic of catch-up sleep. We delve into the complexities of weekend catch-up sleep, exploring a recent study of 91,000 participants that suggests a potential link between compensatory weekend sleep and a reduced risk of heart disease. While this news offers a glimmer of hope, it's crucial to understand this benefit within the context of existing research. Studies like that of Dr. Ken Wright at ...

Transcribed - Published: 6 January 2025