Greg Potter

Tony Winyard 0:00
Habits and health Episode Two. Welcome to habits and health today. My guest is Greg Potter. He runs a company called Resilient Nutrition and he helps a range of individuals improve their health and performance from elite athletes to CEOs. Greg did a PhD on sleep, circadian rhythms, nutrition and metabolism and we're going to investigate quite a few of those areas in today's episode, this podcast is really about trying to give you tips and suggestions and some experiences from people who are experts in their fields and, and habits that you can integrate into your life to improve various aspects of your health. If you do like this, this podcast, why not subscribe, so you get it on a regular basis. And please do leave a review and let other people know what you think about the show. And maybe that will help them to think yeah, maybe I'll give this a listen. So right now it is time for today's show.

Habits and health. And my guest today is Greg Potter. How are you? Greg?

Greg Potter 1:22
I'm very well, Tony, how are you?

Tony Winyard 1:24
I'm pretty good. And where are you?

Greg Potter 1:28
Right now I am in sunny southeast London.

Tony Winyard 1:33
southeast London. Okay, I grew up in northwest London. So that the opposite although that's not where I am now..

Greg Potter 1:40
Cool. I lived up there for a few months at the start of last year.

Tony Winyard 1:43
Okay, and and how has that whole lockdown experience been for you?

Greg Potter 1:48
dynamic. It's been fascinating. And like many somewhat privileged people, I think it's had its upsides and its downsides. For me, one of the things that stands out about it is how we roll with the punches. I live with my girlfriend. And we actually moved in together shortly before the pandemic kicked in. And between the start of the pandemic and now we've moved house 10 times. Wow. I know. So we were moving at a rate of once a month for the first 10 months. And why why was that? Well, it was for various reasons. Initially, it was because the person who owned the flat that we were staying in, was working in Italy at the time. And he got sent back early because they can continue to record obviously, Italy was strongly affected early in the pandemic. So we had to move on from there. But then since then, it's been a combination of factors. But one has actually been us trying to place ourselves in areas that suit us depending on our needs at that time. What I mean by that is that I love London. But when we're locked down, it's not as if many of the things that London's great for are available to you. So it doesn't make that much sense staying in London and paying through the nose for rent, if you can go out and enjoy bars and restaurants and various activities. So we've spent a fair bit of time by the coast within what's the ball and tankerton for a bit. And then in the late summer and early autumn, we moved to Sardinia for a couple of months, which was fantastic. I hadn't lived abroad previously, although I've been relatively itinerant for my whole adult life. And we stayed out there and just fell in love with it. It's a really special place in my heart now and I don't tend to look back at things and feel particularly nostalgic. But on a dark cold winter's morning in London, sometimes I find myself craving beside any beach.

Tony Winyard 4:10
So what made you leave

Greg Potter 4:12
actually came back from work. And it seemed like your opportunity which would be too good to pass up is very random. But a lady sent me an email out of the blue asked me if I wanted to be the sleep expert on a channel for TV programme. And I came back for that. And TV is an interesting world. We spent a couple of days recording and recording several hours but the total amount of time was on TV for about two minutes. Whether it was worth or not in retrospect, I don't know. But it was enjoyable experience and we would come back anyway because that was shortly before Christmas time. And my girlfriend has worked primarily in musical theatre. And as therefore spent most Christmases away from home. So the prospect of being back at home for Christmas and BLT family and friends was too strong to keep us away.

Tony Winyard 5:13
Yeah. Well, and and work and you mentioned about sleep just now and I know you're an expert in health and performance and sleep and metabolism... do you want to tell, tell the listeners more about what it is that you do?

Greg Potter 5:27
Sure, what I would say is, one thing is common toward the work that I do. And that is trying to help people sustainably improve, how they feel and how they perform by way of lifestyle modifications. And I first became interested in this when I was about 12, I had my back playing sport. And I spent most of my free time between then and beginning University finding out about nutrition and exercise. And I eventually studied Sport and Exercise Science after university and did my masters there too. And at that time, I was more interested in physical performance than in health. We worked a lot with athletes, I did some personal training sports massage therapy, I coached a group of 102 100 metre sprinters. But then I increasingly recognised the importance of biological rhythms and sleep to health and performance. So I was looking at options for where to study for my PhD. And I ended up at the University of Leeds, doing a PhD that focused on the relationships between how we sleep, our biological rhythms and what we eat and our metabolic health and risk of diseases such as diabetes. And during that time, I was asked to be a podcast guest by guy named Dan party who has a platform named human os.me. And we got on really well he asked me to work with him, I worked part time as content director during the latter stage of my PhD. And then after that, I moved out into the big wide world not wanting to continue a career in academia that felt a little bit too far removed from people. And I started a health and performance consultancy business. And I now continued to do some of that work, working with individuals in grief, primarily on their sleep, but often on their nutrition and athletic performance, too. I spent much of 2019 working on a digital health startup project didn't come to fruition, but we were trying to create an app that would provide context specific personalised health guidance. And you're trying to engineer the human out of the loop, removing the need for human coaches that then pay off. But I'm still very interested in that. And nowadays, I spend most of my time working on a project named resilient nutrition company that I co founded at the start of 2020, with my good friend, Alan McDonald. And we make food products and supplements with a view to helping people sustainably improve their health and performance. And by sustainable performance, nutrition really refers to three things. So one is making products that tastes really good, because then people will actually use them and experience any benefits that the products lead to. Another is that we want to improve health and performance both in the short term and the long term. And another is that we are considerate of our environmental footprint. So we try and avoid using plastic for instance. And we also give a fixed portion of our sales to an effective charity that works with governments and communities and tropical countries to protect their rainforests, and hence biodiversity and thereby mitigate climate change. So that's what I spend most of my time doing nowadays. And I'm Chief Science Officer. So my main role is formulating their nutrition products. And our first product is aimed at ultra endurance athletes. And it's basically a souped up nut butter based product which tastes fantastic, not not unbiased or anything. And is useful in many contexts. So while we first made it for some growers that we were helping, bro, the Atlantic, we use it ourselves for things like knowledge work, comes in different versions that are appropriate for different times of day. And then alongside all of that stuff. I also do a lot of public speaking. I have spoken in many countries in recent years. Unfortunately, a lot of the public speaking what I was looking forward to last year ended up being cancelled, needless to say, and I also helped a couple of companies but that doesn't take up too much of my time. So that was a very long winded answer. Apologies

Tony Winyard 10:01
So you're involved in quite a few things, there's a few things I'd like to dive into there. One was you talked about the app. So how did you and hopefully, it still will come to fruition? How would that help a person,

Greg Potter 10:17
it would help person by working with them to establish what their goals are, and then help them build healthy habits over time. And one of the issues with existing apps is that they will provide generic guidance. And if you look, for instance, at the notification schedules, then the guidance will be delivered at certain times of day, but they fail to understand the context in which people live. And each of us, each day will experience so called states of vulnerability and states of opportunity. So an example of a state of vulnerability would be if there's somebody who has a history of over consuming alcohol, he is walking past and off licence after insufficient sleep and is prone to making bad decisions, he might well lapse and go in and pick up some beers or something stronger. And if you could use, for instance, GPS data to understand where somebody is in physical space, then you might be able to help that person in real time to make a better decision. An example of the state of opportunity would be somebody who has the chance to make a healthy decision. So maybe they're in their kitchen, and they can choose between chocolate, and something which is better for their health. I'm not saying that that chocolate isn't good for health, but you understand what I'm saying? Yeah. And if in that instance, you can nudge somebody towards the healthier choice, let's say that it's some fish and some fruits and vegetables, then that would contribute to the likelihood of them achieving their long term health goals. And the attractive thing about this approach is that it scales Well, a lot of the more successful online coaching businesses at the moment, still have that person in the loop as I touched on. And if people require coaching, and you're trying to build something that can ultimately reach millions of people, then you're going to need an awful lot of coaches to make that work, especially when you consider the need to have those coaches in different time zones, etc. So if you can build something that can use data, effectively enough to be able to remove that person, the coach, then you could make something which is cost effective, it's available to the masses that helps people in real time. And if you do it right, then you can also quench any fears about things like data security, and you can give the person who's using the app control of their health information. There are lots of things to consider. And it's a difficult problem to solve. But I do think it is soluble, and we didn't succeed. I think that was in part because we were primarily working part time on it across different time zones. And to make something like that that successful. I think you need a really concerted effort involving lots of people close to each other, working full time on the project.

Tony Winyard 13:56
Yeah, I guess if it wasn't for the pandemic situation, if you'd have been in the same space, it would have been more likely to happen.

Greg Potter 14:04
Maybe, but that actually stopped shortly before the pandemic kicked in. So that wasn't pandemic related. But yes, that's certainly possible.

Tony Winyard 14:17
There's so many areas I'd like to touch upon that you mentioned, you talked about metabolism and the effects on circadian rhythms and nutrition and so on. So let's start with circadian rhythms. Because it seems to me it's an area that a lot of people are very unaware of, but it's quite important.

Greg Potter 14:36
It is very important. Yeah. And it's important because our circadian rhythms really affect all aspects of our biology and hence our behaviour. And I can touch on lots of Hadean ribbons are if you like, I don't know where you want to go next.

Tony Winyard 14:52
Yeah, totally because I am. As I said, I think many people aren't really sure about what they are.

Greg Potter 14:57
So I always frame that In evolutionary terms, if you think about organisms on the planet, then they evolved in the presence of predictable cycles in the environment. And the most obvious of these is the light dark cycle, which recurs every 24 hours or say that, with that comes changes in temperature. And to thrive in these changing environments, organisms evolved their own so called biological clocks. And these clocks produce rhythmic changes in biology and hence behaviour, to coordinate with those changes in the environment, optimising them according to time of day. And what these rhythms do is they both anticipate changes in the environment, and they also help us adapt to it. There are different types of these rhythms, the most widely discussed of this kadian rhythms and circadian just means roughly every 24 hours circuit means about the end means day, so bounce of day long. And the most obvious of these is the sleep wake cycle. But there are also cycles in things like body temperature, in how strong you are in your cardiorespiratory fitness in many aspects of your cognition, including things like your ability to attend to a given task, and your immune function, and of course, in processes related to digestion, and metabolism. And going back to this idea that these rhythms help us anticipate and adapt to changing the environment. An example of this anticipation would be that, shortly before you wake each day, your adrenal glands will produce substantial amounts of a woman named cortisol. And the purpose of this response is to increase your alertness and mobilise energy stores in various parts of your body, and to raise your blood pressure. So it's ready for the day ahead. With respect to adaptation, I think that a good example of this be jet lag. So if you fly to the other side of the planet, and if your body's clock was stuck at your home time, then you'd be misaligned with the environment there and you find yourself having a really hard time. But because of so called plasticity, in this alien system, your body's clock could adapt to these changes in the environment. And the way that our body's clocks are synchronised with the environment is very important. Interestingly, if you were to go and live in a cave that is devoid of any time cues, so changes in the light, dark cycle, change in temperature, etc. You have no idea what time of day it was, then you probably find that your body's clock isn't precisely 24 hours. For most people, it's slightly longer than 24 hours, about 24 hours, 12 minutes. And because of that, it needs to be reset each day, needs to be sped up in that case. And the most important cue in resynchronizing, your body's clock each day is the light dark cycle. So you can refer to these as time cues, the technical term is often used as site gabbeh, which just means time giver to German word. And

when your body is exposed, these time cues relative to its own internal time will influence how your body shifts. What I mean by that is that if it's a typical day for you, and let's say that you wake up at seven in the morning, if you experience lots of very bright light, in particular light containing lots of short wavelength lights, so that appears to us as blue green light in the two hours before you wake until about two hours after you wake. And if you exercise at that time, then you tend to shift your body's clock earlier. And you probably find that you feel sleepy later. So you feel sleepy earlier the following evening. If however, you expose yourself to lots of that type of light and exercised very late in the day, so let's say within two to four hours of bedtime, up until maybe two hours after bedtime, then you tend to shift your clock later. So you probably find yourself falling asleep later and then waking up later the next day to and that type of information can be very helpful in the context of something like jet lag, but also shift work. And importantly, when we disrupt our body's clocks, it seems that over time we increase our risk of developing various ailments. And jetlag is an obvious example of this. We know that sorry. shiftwork is an obvious example of this. We know that people who work shifts are at increased risk of various diseases, including certain cancers, but also diabetes. But there are many other lower level instances of this too. And in recent years, people have begun speaking about concepts such as social jetlag, which describes the discrepancy in sleep wait timing on work days versus non work days, certainly prior to the pandemic, a lot of people would shift their sleep later, before the weekend during the weekend, and then when Sunday rolled around Sunday night, they might go to bed late then Monday morning, they had to be up early for work. So it's a bit like flying multiple time zones east as they have to adapt to the earliest schedule during the working week. Yeah, and we know that this might also relate to certain health problems over time. So it's really our modern societies that can lead to disruption to our of our bodies, clocks, and thereby a series of unfortunate health consequences.

Tony Winyard 21:13
And he mentioned about the shortly before, awake in the body releases cortisol and pressure changes, and so on. But that would if someone's only having, say, five or six hours sleep. And so if I'm understanding you, right, that process would happen in stages before eight hours duration. So if someone's only having four or five hours, then what happens then

Greg Potter 21:40
it depends when the sleep restriction takes place. So it's likely that if somebody has four to five hours, in your example, and they wake several hours early, then the consequences of that will be slightly distinct from if they'd had four or five hours of sleep, but they'd gone to bed three to four hours later. That makes sense. But with that said, we know a lot about how insufficient sleep influences many processes everything from how our brains work, to our metabolic health. And because many people are interested in this, I'll use the example of metabolic health and obesity in particular. So if you look at all of the different studies that have asked people how long they sleep, and then tracked their body weight over time, they found that people who report short sleep, which is commonly defined as less than five hours or less than six hours, have about 45% higher odds of going on to develop obesity. And that type of study is limited by many factors. It's just observational, you're just asking people at one point in time, how they sleep, and people don't necessarily perceive their sleep accurately. So experiments in which people come into a lab, and have their sleep disrupted or restricted in this case, can be very insightful. And if you look at all of those studies, then it seems that when people experience sleep restriction, so let's say that they have four or five hours in bed, they typically, of course, are awake longer, so tend to spread out their calorie intake over a longer period of time, the next day, maybe they start eating at roughly the same time, but they finish eating later in the day, we tend to find the probably in part relate to that they eat more calories, and on average, they seem to eat roughly 250 more calories each day, which doesn't necessarily sound like much, that's about the amount that's in a Snickers bar. But if you multiply that by 365 days in a year, then that's roughly the amount of energy in 11 and a half kilogrammes of fat tissue. And the other side of the energy balance equation isn't affected. So while these people are eating more calories, they don't necessarily seem to be burning more calories, that puts them in a positive energy balance which could contribute to weight gain. And the other problem is that how people then metabolise those calories seems to be impaired when people have had insufficient sleep. So an important determinant of metabolic health and risk of diabetes and also risk of some neurodegenerative disorders such as Alzheimer's incidence sensitivity, so how effectively your body dispose of glucose per unit of insulin your pancreas produces. And when people undergo sleep restriction, their insulin sensitivity is impaired. And that could lead to more exaggerated blood sugar responses. And then if that's repeated over time, those accumulative effects could predispose Then to developing diabetes. And we know that insufficient sleep does relate to increased risk of type two diabetes. So if you look at all the different studies that have been done, then people who report shortsleeve, probably at roughly 10%, higher risk of developing type two diabetes per one hour reduction in sleep below about seven hours per night. So the point is that if insufficient sleep is causing people to eat more and metabolise that food less effectively than overtime that could contribute to a variety of downstream consequences, and I've just touched on glucose metabolism, then people should also know that it will also affect a variety of other metabolic health factors such as blood pressure, and stress responses to So that's just one example of how insufficient sleep will negatively affect us. But what I would like to add is that much of the time people focus on insufficient sleep. However, many different dimensions of sleep health are important. And when I say sleep health, I'm referring something which is a little bit nebulous, but if somebody is sleeping, well, then they'll wake up at roughly the same time each day, they'll feel restored, they'll have good daytime functions, they'll feel alert, and they'll have

good working memory, and they'll be in a relatively good mood, then in the evening, they should feel sleepy at roughly the same time each day, go to sleep at roughly the same time each day, and then sleep through the night with few awakenings. So there are a few things in there that are important one is sleep duration, but another is the timing of sleep. So I've touched on biological rhythms and how these are important to health. In the case of shift workers, their problem is that much of the time they're trying to sleep at a time when their body's clock is promoting wakefulness, their sleep quality is, of course going to be negatively affected. sleep quality is an important dimension of sleep health, it's a little bit difficult to measure, but you can look at things like how long it takes somebody fall asleep, the number of times they wait through the night and the total duration of those awakenings, you can also look at more nuanced measures such as the electrophysiology in somebody's brain, which are important to certain processes. And then there is of course, daytime function. And finally, that the variability of these different things too. So in the case of shift work, one of the problems is that people sleep wake cycles, are very variable. And we know that this is independently predictive of certain health outcomes, and ultimately somebodies risk of dying from any cause that will cause mortality. So all these different dimensions of sleep health relate to one another and are important. But obviously sleep duration is one of those. It's an important one.

Tony Winyard 28:02
Only he touched upon when we were talking about the the app before and he chanced upon better habits. So this is things you've just been talking about. How what general advice do you give to people around improving habits to improve their duration of sleep?

Greg Potter 28:20
So I could give you a huge, long answer to this question. I'll try not to do that. So I'm already long winded enough. But what I'll say,

Tony Winyard 28:31
and I know that you've got a free ebook; Principles?

Greg Potter 28:36
Well, I've got a free book, which is available, but that's actually about nutrition specifically. And if people are interested in that they can go to resilient nutrition.com forward slash principles. And the purpose of that is to provide people with principles of how to eat healthily, regardless of their dietary preferences or whether on vegan diets or carnivore diets or paleo diets, etc. those principles still apply. In the case of sleep health, I think that the most important things to attend to probably a little bit different now from what they were two years ago. So in the context of the pandemic, there are some issues that are more problematic than ever. Typically, I would have given a long answer about sleep hygiene tips, which most people are familiar with. You spend plenty of time outdoors each day in daylight, and there's a rule of thumb typically suggest that people spend at least one hour outside during daylight, if possible. And if you're a night owl and you want to shift your sleep earlier, then you want that to be relatively early in your waking day. If you are, for example, an elderly person who wants to shift your sleep later, then you want that to be relatively late in the day. Another example of these would be to be physically active. If you take somebody who's sedentary and you put him on Through a structured exercise training programme, nothing heroic, then they'll tend to fall asleep fast, feel like they sleep better, sleep slightly longer and have best daytime function too. So, government guidelines advocate at least 150 minutes moderate to vigorous intensity physical activity per week. Doesn't matter too much how that's distributed. And people should probably doing some form of resistance training a couple of times a week for major muscle groups that doesn't have to entail going to the gym that would be doing simple at home bodyweight exercises such as split squats, push ups, 40 rows, chin ups, that type of thing. The other ones of course, are like avoiding caffeine too late in the day, from one person to another, there are very large differences in how they metabolise caffeine, and because of that, some people will find that they can consume it in quite large quantities quite late in the day and they'll feel that it barely affects Firstly, whether it actually affects their sleep a slightly different story, whereas other people will feel hypersensitive to it. As a rule of thumb, I typically recommend that people consume up to about three milligrammes per kilogramme. And there's a website named caffeine informer.com, where you can find out the caffeine content of commonly consumed foods and drinks. And people stop consuming it maybe nine hours or so before they plan to go to bed. But like I said, that is subject to very big differences between people. The problem with caffeine is that it reduces the pressure to sleep that accumulates with wakefulness. So when you wake up each morning, if you've slept well, then your body will have the full pressure to sleep because that's paid off during the sleep period. But then, as wakefulness continues, certain chemicals accumulate in your brain, in particular one named adenosine, and these promotes sleep. Caffeine blocks the interaction of this adenosine, whether it's receptors, and thereby reduces that sleepiness signal so that when your habitual bedtime rolls around, you might find that it takes you longer to fall asleep, but also that your sleep is lighter. There is some evidence to the caffeine consumed very late in the day can actually shift the body clock later. Not by way of affecting that's the pressure system.

So that's caffeine. Alcohol is another obvious one. Historically, people have used as a nightcap when people drink they tend to fall asleep faster and spend a great proportion of the early sleep period in the deepest stage of sleep, which is important some processes, but problem with alcohol is that later in the sleep period, it tends to break up sleep. And it does so in several ways. One is that it tends to increase urination so people are more likely to need to pee in the middle of the sleep period. Another is that it's a muscle relaxant. And if you're snore, or if you have a sleep related breathing disorders, such as sleep apnea, then you might find that the muscles of your upper airway are more likely to collapse, leading you to snore more or to experience more severe episodes of sleep apnea is which the pipe nears. So that's not good. And then, alcohol itself is also metabolised into Estela heijden acetate, which can lead to all sorts of other problems that could disrupt sleep too, plausibly, that's alcohol, and other of course, is nicotine. Nicotine acts on certain coda nergic receptors in the brain to promote wakefulness, so consuming lots of nicotine late in the day is likely to disrupt sleep. With that said, if you are a smoker, and you're going through a period of nicotine abstinence, then you might find that your sleep suffers temporarily. So nicotine patches, for instance, can be helpful. And then there'll be a process of weaning yourself off them. So people who are smokers will respond quite differently from people who aren't smokers. Then there are other factors to consider. So one of these causes nutrition, and we might touch on this more later. But with respect to the timing of nutrition, it's likely that it's best for you to go to bed neither hungry nor fall, and to not eat within a couple of hours of going to bed. And there are several reasons for that. One is just that when you eat, your body temperature will increase shortly thereafter, as you digest and metabolise that food. And this is known as the thermic effect of feeding or diet induced thermogenesis and it typically accounts for about 10% of the number of calories that you consume. So if you have a 500 calorie meal, you probably spend about 50 calories, just breaking down metabolising that food And that number, that proportion is highest for proteins but lower for carbohydrate. Fat seems to be the lowest such quite high alcohol, interestingly, but that's neither here nor there. And if your body temperature is too high as you try and go to bed, then you'll struggle to sleep. I mentioned earlier that circadian rhythm and body temperature. And what we're after is a drop in brain temperature, in particular around the time you go to bed. And if your body temperature isn't falling, because you've eaten too much too late, then you might find it harder to nod off. Now, that actually brings up another sleep tip, which is, if you have a hot shower, or hot bath, perhaps 10 minute long shower and about 40 degrees Celsius, one to two hours before you go to bed, you'll increase the temperature of your skin. And when you then get out of the shower or the bath and dry off, you'll actually lose heat from your core faster than you otherwise would. And you'll find that you fall asleep faster as a result. And you might also increase and other measures of sleep quality. So that's a simple tip that people can people can use. Now, with respect to temperature, the temperature of your bedroom is important. And the ideal air temperature on average is probably between 18 and 20 degrees Celsius. But as always, there's quite big variation between people in that preferred temperature that you want it to be cool. Obviously, you want it to be dark as well. Light has alerting effects, the least alerting lights is red light. So if you have an alarm clock, you probably want to pick one that emits red light. And then noise can disrupt sleep. So you want to try and cancel out any extraneous noises that could otherwise disturb you. I don't want people to be neurotic about this stuff. But I just want to provide a complete answer. So ways you can do that include, for example, using silicone earplugs or using a white noise machine. And

then there are a variety of other things which are less centred on sleep hygiene, but more pandemic specific. And I think that right now, a lot of people are struggling with their sleep, because they're under a lot of stress for various reasons. And that might be because they've lost a job might be because they've lost a loved one. It might be that they're feeling lonely, and loneliness does predict some sleep difficulties. And if that's the case, then you of course, want to try and identify the actual source of the problem and see to that. But if you're experiencing stress related sleep problems, then you of course want to have things that can help you better cope with that stress. And there are some simple strategies to this end, one that I really like is a little bit strange sounding some people but scheduling worry time. And the point is that many of us are busy during the daytime. And our work might suppress any anxieties and ruminations that we experienced. But then by the end of the working day, all of a sudden, these percolate to the surface. And because of that, if you put aside about 20 minutes, round dinner time, maybe just after dinner, to dedicate to worrying about things, then what you can do is at the end of that period of time, you can say to yourself, I'm not going to worry again for the next 23 and point six, seven hours until my next bout of worry time. And the idea is we're trying to get them out of your head. So what you would do is you'd simply sit down with a pen and a piece of paper with some sort of note taking device. And in one column, you list the battery. And in an adjacent column, you could list the next thing that you can do to help address that particular worry. And if there's nothing that you feel you can do to address it. So let's say that the worry is some sort of existential threat like climate change, then that's fine, just missed that there's nothing you can do about it right now the mere act of writing that down, might very well help you. And then, in terms of some other things that people should really be attentive to right now, I think a key one relates to something named stimulus control of behaviour. And people will have heard of Ivan Pavlov, who's famous for his experiments on dogs. And he came up with this concept of classical conditioning. So what he did was he did experiments on dogs and he found that over time, the mere presence of an experiment would lead the dogs to salivate because they'd learned that the experimenter was bringing them food and he found If he could pair a certain stimulus with the presentation of food, and then the presence of the stimulus alone could cause the dogs to salivate. And he used the bow in this instance. And the point is that, like dogs were very associative beings. And if you've been struggling with your sleep, and because of that, you're putting pressure on yourself to sleep and you're spending more time in bed and you're doing away with other work or social obligations to try and increase your sleep opportunity, then you might find that you're spending more time in bed awake. The problem with that is that you learn to associate being in bed with being awake, and you need to retrain yourself to associate being in bed with being asleep. And the way that you do that is to first only go to bed when you're actually sleepy. Second, if you're in bed, and you mean to sleep, and don't fall asleep, within 1520 minutes, you should get out of bed, do something relaxing, and then lighting in a different room, if possible, and then only returns about when you're sleepy and good activities this time treat things like reading a book in dim lighting article like meditation, I didn't touch on that earlier. But that's because it's so widely discussed Nowadays, there is evidence that mindfulness meditation can enhance the particularly in people with certain disorders, including anxiety disorders and pain problems, because pain can obviously disrupts it too.

So meditation would be an appropriate thing to do at that time, too. And then another key principle is to only use the bed for sex and sleep, nothing else. So no reading in bed. And this rule is slightly different for people with sleep problems versus people who don't have sleep problems. If you are healthy sleeper, then you probably shouldn't be listening to this interview. If you are a healthy sleeper, then it's fine for you to read your book in bed, don't worry about it. But if you're not, then again, the rules are slightly different. So I think that's a key principle for people. And then finally, there are a couple of other things. One is regularity is important. And that pertains not only to when you go to bed, and when you get out of bed each day, because that will have a bearing on your sleep duration and your sleep quality too. But also on things like when you eat each day, when you're outside each day. And ideally, when you exercise each day, although importantly, I'd rather that somebody exercises, full stop versus not exercising, because it's not the right time of day to exercise. And we can get to exercise time later if you like. But that type of regularity of these time cues, is important to sleep health as well. So I could go on and on about this stuff. But I think those are some low hanging fruit for lots of people. Yeah,

Tony Winyard 42:56
there's some good tips there. And I'm wondering,; changing the subject slightly while moving away from sleep? I know that you're an expert in metabolism as well. And it seems to me that again, that's a phrase that I think is often misunderstood exactly what metabolism is and how it affects you.

Greg Potter 43:19
Yeah, and the reality is that somebody's metabolism, is the sum of all chemical reactions in their body. So we're talking about something which is enormously broad. And I know that I often look back at talks that I do or podcasts that I'm on, I think about how nonspecific I am when I speak about some of these things. But when people discuss metabolism there, of course, variety, all sorts of different processes at different levels of organisation in their bodies, including things like inflammation, which has a strong bearing not only on immune function, but also on things like somebody's likelihood of experiencing pain, somebody's susceptibility to low mood, and a variety of other health consequences. We're speaking about blood sugar regulation, we're speaking about blood lipids. And people sometimes also refer to cardio metabolic health, which also comprises the cardiovascular system. So in that instance, you might be making heart rate, heart rate variability, somebody's blood pressure, somebody endothelial functions are how well their blood vessels work. And all these different things interact with each other, to influence some of these health trajectory over time, and how they feel each day.

Tony Winyard 44:46
What's your thoughts on? I'm switching back and forwards here. Thinking about sleep, some of the stuff you just touched upon, for some reason, Wearables came into my mind. And I wonder what your thoughts were on these type of things like the Oura ring, Whoop Strap, fitbits, and so on?

Greg Potter 45:10
Yeah, I'm often asked about this. And I think it's a more important subject now than it was a few years ago, I remember being in a sleep conference in 2015. And the speaker asked the people in the audience and these people who are fascinated by sleep, how many of them have something like a Fitbit, and two people raise their arms. And you repeated that in 2021, then I suspect that 80% of people in attendance would raise their arms. So with that said, My feelings about them are somewhat mixed. I think that used wisely, they are helpful. For most people, I think that interpreted incorrectly, they can actually lead to more harm than good. So let me just expand on that. When I say used wisely. What I mean is that there are certain data that those devices will provide people with, that can be informative. And if you are somebody who's currently stuck at home, and you're less physically active than you were previously, then I think a large part of the utility of these devices is that they'll make you aware of the fact that you're taking fewer steps than you were previously. And in studies in which people are given these wrist worn wearables, and then given feedback about their step counts, they do tend to take more steps. And that is important to various aspects of our health, of course, not only cardio, metabolic health, but also things like mood and cognition. So I think physical activity data are important. They seem to be better from wristwatch and wearables than from finger worn wearables like rings. And I'm most interested in step count, because it's quite difficult to quantify things like training loads of somebody's cycling. And the estimates of energy expenditure don't seem to be particularly good based on the data and published so far, whereas the step count numbers seem to be relatively accurate. So I think that's a useful metric to look at. With respect to readiness each day, how well rested you are, I think that pulse rate data can be helpful. And when I say pulse rate, I'm a bit of a stickler for detail sometimes. But I say pulse rate, because it's being measured at the wrist or the finger, heart rate data come from measurements taken over the heart. So you need a chest strap for heart rate. But the pulse rate data can tell you something about your readiness. And you'll generally find that the more stressed you are, in general, the higher your resting pulse rate, and the lower your pulse rate variability. So how your pulse rate changes from one beat to the next. In this instance, higher pulse rate variability is generally a good thing and an indication that you're relatively well rested. And for those days, where I suspect that finger wall marbles or betters, or something like an aura ring, because the fit is more snug. Now, with respect to sleep data, I think there are lots of things to consider. So one is whether somebody is just somebody who doesn't get enough time in bed. So let's say that you're busy, you have to wake up in the morning to get the kids ready for school, you've got a big schedule of work to get to. And because of that, you wait to an alarm in the morning. And maybe you go to bed later than you would like and you're restricting your time in bed by an hour and a half versus what your body would prefer. So if you need eight hours in bed, and you're getting six and a half hours in bed, then the way that these devices are helpful is just by alerting you to that you might not otherwise realise that you're consistently only giving yourself insufficient time to sleep. Well, I'm sure that you would feel the consequences of that, even if you're trying to compensate by way of caffeine. So for that person, I think looking at the trends in the data over time is very helpful. However, let's say that you have a sleep disorder. If you have insomnia, then the estimates of sleep duration from these devices are unlikely to be particularly accurate, because you might be lying in bed still, and therefore being schooled as being asleep but you're wide awake because you can't sleep because of your insomnia. So for that type of population, the data aren't going to be so helpful. If you have a

disorders such as periodic limb movements, in which you thrash around in bed at night, even though you are asleep, then the device is likely to score you as awake when you are in fact asleep, so those data won't be so good. So, the more unusual somebody sleep is, the less likely the devices are to give good sleep data. And in recent times, the devices also tell people something about what the algorithms suggest about their sleep stages. So when we sleep, we go through different stages. Obviously, when we fast fall asleep, we go into a very light stage of sleep. And sleep gets progressively deeper, until we're in so called slow wave sleep is very important. restorative processes, such as the regeneration of connective tissue, but also it's important to the formation of memories both in the brain and in the immune system. And it's important to the clearance of waste products and certain parts of body including the brain to, then you typically go into a light stage of sleep. And that light stage sleeps very important, some aspects of learning. And then you go into so called REM sleep, rapid eye movement, sleep, which is the stage of sleep in which we do most of our dreaming. And that seems to be very important to things like our ability to regulate our emotions, our ability to learn motor skills. So during that stage of sleep, it's as if our bodies have a safe space in which to try and make sense of the world. And our muscles are primarily paralysed to stop us from acting out our dreams.

And that creates that type of safe environment so that we can try and better understand how we interact with everything around us. And because of these functions of different stages of sleep, people are very interested in trying to understand their own sleep stages. And the devices will use things like body movements, temperature and heart rate changes, to estimate when somebody is in, for instance, slow wave sleep versus REM sleep. But they don't seem to be that good at doing that. I think they're getting better over time. There are some data showing that the latest whoop strap might be not too bad at this, for instance. But they're not as good as devices that measure what's going on in the brain. And so finally, the best devices for assessing sleep are probably headworn devices. My personal favourite is the so called dream to headband. problem is it's very expensive, but it uses electrodes placed over the brain to measure electrical activity in the brain. And it's seemingly quite good at staging sleep. It also comes with a cbti conservation behavioural therapy for insomnia like programme and take somebody's sleep data, and then provides personalised guidance by its assistant app. And the guidance, at least to my eyes seems to be better than much of the guidance you'll get from some of the other wearable devices. And this headband also has some other advantages too. So it's got some positional sensors that will tell you when you're sleeping on your back versus your side, for instance. And that's relevant in some scenarios. So if somebody's got obstructive sleep apnea, then sleeping on their back will exacerbate those periods of not being able to breathe, as well. So that's a great device for that. But obviously, it's not something you wear during the daytime, they won't give you any physical activity data. So that has its own limitations too. And that, of course, brings us to personal preferences. And the advantage of something like an aura ring is that people tend to keep them on, I think the form factor is something that you shouldn't overlook. Whereas risk worn devices can be a bit more cumbersome, people might be more likely to stop using them over time. And the orings are also quite quite simple, relatively elegant design. So a lot of people favour them for that reason. So there are those types of devices. And then I could go into some other types of sleep tech that are designed to help people sleep. But I'll pause there. And I'll end actually by saying that the devices that are really relevant to sleep that sometimes get lost in this conversation, although I think people are more aware of this now are things like smartphones. And this will seem ironic based on what we're discussing at the start the utility of using a smartphone delivered app, but people are using their smartphones more during the pandemic. And there have been several studies that quite convincingly show that using smartphones close to bed will lead people to stay up later. take longer to fall asleep and then possibly be more likely to wait more frequently during the night too. And so some simple strategies like turning off smartphones, at least half an hour before bed can be helpful, I think people should absolutely keep those devices out of their bedrooms, leave it in the kitchen on charge. And one thing to mention related to this is that the effects of smartphone use and screen time on sleep, of course, depends on the content. And once again, this is very relevant right now, because we're being bombarded with, in many instances, negative news about vaccines, or how cases and deaths from COVID-19 are changing over time. And it therefore is important to carefully curate our intake of negative news. And I think that the middle of the waking day is the best time for this. So using site blocking apps, I use self control in my Mac, for instance, to block yourself from things that you're prone to overindulging on as you as you go through another cycle of doom, scrolling can be really helpful.

Tony Winyard 56:21
Yeah, I agree completely. I stopped watching the news altogether. And I rarely watch television, and I think I feel in a much happier state than most people as a result, I was wondering about when you were just talking about using phone and so on. And there's a few books I've read, which seem to suggest, and I don't know whether this is accurate. But they suggest that as you're falling asleep, you go into a different state. And I forget Now I know there is theta and gamma and all the different states, that you go into a state that's more receptive to your brain remembering specific information that you're trying to learn. So they suggest, that if you're learning a language, for example, doing an exam, and whatever it may be, by playing something recorded around that time, it's it's more likely to stick.

Greg Potter 57:17
Yeah, so this is an area of research known as target, target memory reactivation. It's not something I've looked at for several years. But the idea is that we can use certain sensory stimuli, and pair them with a learning stimulus, and then re expose ourselves to those pads stimuli during the sleep period. And thereby, if you like, tickle the brain, into replaying the information that was learned there, by better consolidating it into memory. Yeah, so the different types of sensory stimuli that you can use include things like music. And you could also potentially use some other sensory stimuli, such as olfactory cues. So maybe, while you're learning, you have some lavender next to you, and you could then sleep with the lavender by your bedside. I don't see much of a downside to this. I think that olfactory cues are probably most practical, there is some evidence that lavender might otherwise be helpful for sleep, particularly in anxiety. So I wouldn't really hesitate to keep a couple of millilitres of pure 100% lavender oil by the bedside, and then keep that by you during the day if you're learning something important. And then a related question is, what the best time of day, which to learn new things is if you're trying to consolidate that information as well as possible into your long term memory. And I don't think the answer to that is that clear. I think it's likely that if you try and learn something, too soon after waking up or too close to bedtime, then that might not be ideal. But one thing that is very relevant here, is napping. And it does seem that if somebody deplete somebody who's short on sleep, goes through a learning task and then is allowed to nap shortly thereafter. Then he or she might better memorise the learned information. And there's also some evidence that the addition of an exercise bout before the learning task, and then having the nap after the learning task might further boost the memory enhancing effects of the nap too. So if you're a student and you're burning a candle and you're not getting quite enough sleep at the moment, then making sure you do some activity and then placing your key learning shortly before a brief nap in the middle of might be helpful. And something to recognise here is that I touched on earlier, the fact that different stages of sleep are important different processes. And this is likely true of memory consolidation too. So, for instance, REM sleep, the stage of sleep in which we dream seems to be very important to getting the gist of something. If you're doing a multiple choice questionnaire test, and you don't know what the right answer is, but you've got an inclination, then you might be more likely to have that inclination if you've had sufficient REM sleep the night before. Whereas if you're just trying to remember an isolated fact, then it seems that deep sleep might be more important. So the actual architecture of sleep testing to be important to memory formation to

Tony Winyard 1:00:52
Greg, we've been speaking out already, and there's about a million more questions I'd love to ask. I want to be respectful of your time. So, maybe you can come back to be a guest another time to cover some other areas?

Greg Potter 1:01:09
Yeah, of course.

Tony Winyard 1:01:12
If people want to find out more about your social media links, and so on.

Greg Potter 1:01:19
Please, I'd be most inclined some people is actually https://resilientnutrition.com which is that company that I mentioned earlier. Yeah. And we're on social media at, not resilient nutrition is too long. So resilient nuts, https://www.instagram.com/resilientnuts/ it is because we are a bunch of nuts after all. And then my personal accounts are at Greg Potter, PhD, I used to use Twitter, I don't really anymore. I use Instagram a bit. And I recently came out with a series of sleep tips that people will be able to see that. And I do have a website, which is very crude, but that's http://gregpotterphd.com And you can find a way to reach me there if you like. So I think those are where I'd direct people. As you mentioned earlier, there is a free e-book that I wrote recently. So check out the Principles of resilient nutrition - https://resilientnutrition.com/pages/principles/ , if you're interested in that. We haven't touched on that stuff today. But really good feedback on it so far, and a lot of people seem to be finding it of use.

Tony Winyard 1:02:21
I'll put a link to that in the show notes as well as for your social media. Thanks. And finally, Greg, do you have a book that you recommend?

Greg Potter 1:02:33
Yes, if people are interested in behaviour in general, some of the things that we've touched on today are biology more broadly than my favourite book on that subject is behave by Robert sapolsky. He spent most of his career studying stress in non human primates. And it's a fantastic book. It's dense, but it's well written. It's extremely comprehensive. He's a fantastic communicator. And I think there's a huge amount to be learned from it. If you just buy one book. Read over and over then, in some instances that will serve you really well. And that's one of those books. I think for a related book, I'd probably pick that one.

Tony Winyard 1:03:26
I'll put a link to that in the show notes as well. Greg, it's been a real pleasure speaking with you. And thank you for sharing so much. Fantastic information and your knowledge.

Greg Potter 1:03:36
A pleasure. Thanks very much, Tony.

Tony Winyard 1:03:40
Thank you. Join us next week for Episode Three of Habits and health, where my guest is Farah Nanji. She's a DJ, a journalist, has spoken at a TEDx. And she's the founder of Regents Racing, a business, exploring leadership lessons from Formula One. And she's had quite a few things happened in her life that have been quite extraordinary. So that's next week's episode with Farah Nanji. Hope you enjoyed this week's show. If you know anyone who you feel would get some value from some of the great information that Greg shared with us, and his wisdom about sleep and metabolism and circadian rhythms and so on. If you do know anyone who would really benefit from that, why not share the episode with them, maybe take a screenshot of this and send it to them, post it on social media, whatever. please do leave a review and subscribe to the podcast as well. And hope you have a great week and see you back next week with Farah Nanji.

Transcribed by https://otter.ai