The Matt Walker Podcast

Today’s episode takes two questions as its subject: first, why does someone develop insomnia, and second, what adds gasoline to the sleep-disorder fire of insomnia and only makes it rage more powerfully? These are two very complex questions, but through lots of great science and wonderful scientists, we now have a conceptual model explaining how you may find yourself falling into the pit of insomn...

There is no quick test that can determine insomnia. Instead, the diagnosis of clinical insomnia disorder is based on a set of clinical assessment and interviews. These center on three core features: 1) difficulties falling asleep, 2) difficulty staying asleep, or 3) waking up and not feeling refreshed by your sleep.  Furthermore, to receive the diagnosis, you often have to be experiencing these th...

Today’s episode is the first in a 7-part series on insomnia. Matt starts with a calming reality—insomnia isn’t a single bad night or a string of bad nights of sleep. In the US, epidemiological studies have suggested that insomnia disorder is as prevalent as the obesity epidemic: around 10-15% of the population suffer from clinical-grade insomnia, making it the most common sleep disorder. Indeed, o...

Today’s episode focuses on optimising your sleep. It’s designed for people who don’t have clinical insomnia but would like to fine-tune their sleep. Matt goes over five conventional tips, and five unconventional tips that may be new to you.  The first tip is regularity—going to bed and waking up at the same time every day. Your brain has its own master 24-hour clock, the suprachiasmatic nucleus, w...

Matt is back this week with his recurring series, ‘Sleep is Bloody Remarkable’. Today’s episode is all about why we are unique when it comes to sleep.  When we compare our sleep to that of all other primates, humans stand out in two ways. First, we spend far less time asleep, and second, and in bloody remarkable 😂 contrast, humans get more than double the amount of REM sleep. Unlike many other pr...

In this episode, Matt goes deeper into his exploration of  lucid dreaming. He tells us all about studies demonstrating that lucid dreamers can wake from dream sleep on command, demonstrating control over intention in their dreams, and even bring themselves to orgasm in dream sleep! Matt tells us about two leading methods for developing the skill of lucid dreaming. The first is Mnemonic Induction o...

In part five of his series on dreams, Matt discusses what lucid dreaming is and how it was scientifically proven to be real. We define lucid dreaming as the moment when an individual becomes aware they are dreaming. Historically, the concept of lucid dreaming was considered a scientific scam. First, to claim that people can gain conscious control over a normally unconscious process injects a heavy...

Today’s episode focuses on a second but very different function of dreaming: the ingenious processing and interconnection of memories that inspires creativity and even problem-solving ability. Matt describes how we can think of REM sleep dreaming as a form of informational alchemy, in which we build new connections. As a consequence, we wake the next morning with a mind-wide web of associations ca...

Matt’s back with part three of his series on the science of dreaming! In this episode, he discusses how he and other scientists have discovered that dreams are not simply an  unintended by-product of REM sleep. Instead, dreams provide at least two essential benefits for human beings. The first of these functions involves nursing our emotional and mental health and is the focus of this episode. Mat...

In the second episode of this series about REM sleep dreaming, Matt explores what the science has to say not only about how we dream at the brain level, but what it is that we dream about.   T raditionally, civilizations such as those in ancient Egypt, believed that dreams were a form of divine intervention--a message from the heavens. Thereafter, Matt discusses Sigmund Freud, who introduced the n...

This week’s episode is the first in a new multi-part series all about dreams! Today, Matt focuses on the question of how your brain generates these things called dreams. Matt starts with an unexpected statement: last night, when you were dreaming, you became psychotic. 5 things happen when you dream that justify his diagnosis: 1)  you see things that aren’t there, 2) you believe things that could...

Matt has a special announcement this week: a new recurring type of episode called, ‘Sleep is Bloody Remarkable’. This series of episodes will share fascinating facts about sleep that will  blow your mind! In the premier episode, Matt focuses on something truly (bloody) remarkable: half-brain sleep, or unihemispheric sleep.   Unihemispheric sleep is the phenomenon of when one hemisphere of the brai...

Matt returns with Part 2 of his series on sleep and weight gain. This time around, he teaches us how a lack of sleep not only makes you eat more food, but changes what types of food you want to eat, and eat to excess. First, Matt describes how underslept individuals that are limited to 4-5 hours of sleep for several nights will experience a 33% increase in the desire to eat obesogenic, sugary trea...

Matt kicks off a two-part series all about sleep, eating, and weight gain.  He starts by introducing two appetite-regulating hormones: leptin and ghrelin. Matt explains how leptin sends a signal of fullness, to your brain. When leptin levels are high, your appetite is reduced, and you feel satisfied by the food you eat. Ghrelin does the exact opposite. It revs up your hunger, so when your ghrelin...

In the previous episode, Matt described the role of temperature in helping us fall asleep. In this episode, Matt teaches us all about the role of temperature in helping us stay asleep across the night, and then more effectively wake up the following morning. First, Matt takes us back to the body temperature suit experiments that were able to warm or cool different parts of the body. Matt explains...

In today's episode, Matt reveals how 1) your own temperature and, even more precisely, 2) the temperature of different parts of you, as well as 3) the temperature of your bedroom, can change how well or how poorly you sleep at night. Matt describes the basic physiology of how your brain and body needed to drop their core temperature by about 1 degree Celsius, or about 2 to 3 degrees Fahrenhei...

In today's episode, Matt takes us on a deep dive into melatonin. He covers four main topics: 1) what is melatonin? 2) how does melatonin work? 3) what does melatonin do, and *not* do, for sleep? 4) how can we think about melatonin supplementation? First, Matt describes that melatonin is a naturally occurring hormone released by the brain. He gleefully notes that melatonin is often called, “th...

In this week’s episode, Matt continues his discussion of sleep and caffeine. Here, we learn about the paradox of coffee, one in which coffee provides health benefits, despite its negative impact on sleep. Before addressing that, however, Matt speaks about one last sleep consequence of caffeine: regardless of your sensitivity to caffeine, it can still disrupt the quantity and electric quality of yo...

In today's episode, Matt unpacks the world of coffee, and caffeine in the first of a two-part series on caffeine. Matt describes the numerous health benefits associated with coffee, the fact that Matt has even changed his tune a little and advocates a morning cup for some. Matt may not have anything to do with caffeine itself, with more details on that in part 2. In part 1, Matt then takes a...

On last week’s episode, we learned about the three main ways alcohol can harm our sleep: 1) alcohol results in sedation rather than naturalistic sleep, 2) alcohol causes sleep fragmentation, and 3) alcohol impairs REM sleep.  Today, Matt dives into each of these negative impacts, explaining exactly how and why alcohol disrupts our sleep in these specific ways. First, alcohol is a class of chemical...

Although some people may believe that a drink or two in the evening will help them sleep better, today’s episode shows us that alcohol harms our sleep in several different ways. In the first of two episodes on sleep and alcohol, Matt talks about alcohol as a chemical, and the main ways it negatively affects our sleep. Alcohol has a sedative effect that switches off brain cell firing as we sleep. A...

As the great Roman poet, Ovid, once said, “There is more refreshment and stimulation in a nap, even of the briefest, than all the alcohol ever distilled.” But are naps always a good thing? Are we even designed to nap? And if you do nap, when should you do it, and for how long?  Today Matt explores the benefits and pitfalls of napping, how napping may fall in line with our pre-programmed sleep patt...

In the final episode of our three-part series about chronotypes, Matt examines the question of  whether your chronotype is truly fixed, or if you can change an evening type to a morning type (though you will hear that Matt’s preference is for society to change, not the individual).  Matt reviews a fascinating study by an Australian-lead research team that tried to turn night owls into morning lark...

In the second episode of our three-part series on chronotypes,  Matt speaks about what happens when you do not sleep in harmony with your natural chronotype. Unlike morning larks, night owls simply cannot fall asleep easily early at night, which leads to the first and most obvious consequence of not sleeping in line with your chronotype—you don’t sleep as much. Matt explains that morning types sle...

Episode 04: Chronotype: Part 1 Summary Are you a morning type? Or are you an evening type? Perhaps you are neither of the two? Today’s episode is the first in a three-part series all about your chronotype, or your body’s natural biological preference to be awake and be asleep at a certain time.  Matt begins by explaining exactly what your chronotype is, then breaks down the three main “flavors” of...