Written by Christopher Kelly
Jan. 3, 2020
Christopher: Well, Greg, thank you so much for joining me again this morning for me -- obviously, I've already been out walking the dogs because that's what you do, isn't it, to entrain your circadian rhythm -- and afternoon for you. How was your sleep last night? The last time we spoke, you weren't sleeping that great.
Greg: It was okay. It's been okay.
Christopher: Just okay?
Greg: Yeah. It hasn't been my best week, but it's been good enough. If I don't make any sense today though then I'm blaming it on my sleep. I've always got that to fall back on fortunately.
Christopher: Do you think it's helpful or a hindrance to know as much about sleep physiology as you do when it comes to the practice of sleep?
Greg: I think that in this instance, a bit of knowledge can be a bad thing. When I started learning more about things such as insomnia, I feel that my sleep initially suffered because I became more attentive to sleep-related cues and I think it's a very fine line that people like myself walk as people who are involved in education about sleep because on the one hand, you want to make it clear that getting good sleep is essential to well-being and also that poor sleep does predispose people to a variety of health and performance problems, but you don't want to engage in fear mongering and you don't want to perhaps inadvertently make people sleep worse as they become more and more aware of how they're sleeping.
So I feel that over time, I've tried to shift my focus a bit to emphasizing the beneficial effects of getting better sleep more than the negative consequence of getting poor sleep, but certainly I'm often reflecting on things like podcasts that I go on and talks that I give and wondering how I can better deliver that content such that it actually helps people sleep better rather than just giving them lots of information about sleep especially in conversations like this when we're speaking about sleep problems. It is tricky to actually achieve that, but hopefully we'll do a half decent job of that today.
Christopher: A slightly related question, do you think in the general case, it's harder to coach yourself than it is for you to coach somebody else?
Christopher: In a word, yes.
Greg: Yes, it certainly is. In my case, I just get stuck in my ways quite easily especially with things like exercise. With my diet, I feel like that's been a good thing over time. I can very easily maintain a certain body composition. I generally feel pretty good and so on, but with exercise, that can quickly lead to stagnation because if you consume a healthy diet and you rotate your food choices so you get plenty of variety and so on, it doesn't need to change drastically over time necessarily whereas with exercise, you need to progress it systematically. Now, I suppose that sleep would probably be more similar to diet in that respect because one of the keys to sleeping well is regularity.
Christopher: That tells me you're doing something interesting there, the progressive overload. It means that you're training with a particular goal in mind. I'm sure you've seen a documentary that features modern hunter-gatherers and they look completely ripped and they have no idea what a gym is, let alone what a barbell is, right? It tells me you're doing something interesting.
Greg: I actually watched that BBC documentary that you recommended on Slack which was about Neanderthals. There's a footage of breakdancers who had been tagged with these motion sensors and they were showing how Neanderthals would've danced. It was a bit ridiculous at times, but there was a cameo appearance from Dan Lieberman, so that made it worth it.
Christopher: Yeah. I'll link to that in the show notes for this episode. That was on the BBC and it was Andy Serkis, wasn't it, that coordinated the motion capture because that's what he does.
Greg: I'm not sure. I just remember there being a very entertaining Dutch guy.
Christopher: Yes. Andy Serkis, I'm pretty sure he played Gollum in Lord of the Rings, so he's an expert on motion capture for sure. Yeah, [0:04:12] [Indiscernible] BCC documentary. They're making some really good stuff still. You can't just turn the telly on and start watching. You have to watch it on the iPlayer, do it on demand because there's not good stuff on all the time, but on demand, it's very, very good.
Greg: You've got to love the Beeb.
Christopher: Yeah, definitely. Definitely. Well, let's talk about sleep then. Last time, what did we tell people?
Greg: Quite a lot.
Christopher: Can you summarize it in less than 30 seconds?
Greg: I think we focused primarily on some strategies to help people fall asleep faster. We've touched on some of the core things that are involved in assessing insomnia, diagnosing somebody who has insomnia, some consequences of insomnia on things like daytime function.
What we didn't touch on, which I did right about in the article series for Nourish Balance Thrive, Bedtime Restriction Therapy. I glossed over that briefly thinking that we would circle back to it. We also didn't really speak about meditation, which can be particularly helpful for certain sleep problems. Finally, we didn't get to some of the unique sleep difficulties that arise from intensive training, and according to which type of athlete you are, there are some things that you'll be predisposed to, so it'd be nice to give people some strategies to help circumvent those issues.
Christopher: Excellent. It sounds good. Should we get into the sleep restriction therapy? Can you tell us what it is and when it might be appropriate?
Greg: Sure. Sleep Restriction Therapy is probably the most potent technique that's used to help people who have insomnia. It's primarily used for sleep maintenance insomnia, which I discussed last time to overview briefly, difficulty staying asleep once you fall asleep. The idea behind Bedtime Restriction Therapy or Sleep Restriction Therapy is to assess somebody's routine sleep, first and foremost, so that you have a clear idea of how long they're sleeping, so we'll pick some numbers to make this simple for people to understand.
Let's say that somebody has sleep maintenance insomnia and they're currently spending ten hours in bed each night, but they only actually sleep for six of those hours, so their sleep is 60% efficient. What you would do if you are guiding this person through Bedtime Restriction Therapy is have the person delay their bedtime such that instead of spending ten hours in bed, they're now spending six hours in bed because that's how long they actually sleep before on average each night and they get out of bed at the same time each day as they were on average during that period of measurement preceding the restriction therapy.
Let's say that Sally has sleep maintenance insomnia and she goes to bed at 10:00 p.m. and she gets out of bed at 8:00 a.m., ten-hour sleep opportunity. If she's asleep for six of those hours, she would delay her bedtime to 2:00 a.m. and then continue to get out of bed at 8:00 a.m. What she would find during this time is that because she's spending a longer period of time each day awake, she would accumulate more pressure to sleep at night, so by the time she goes to bed, she's very sleepy. Because of that, her sleep would quickly become more efficient and more consolidated. During the first few days of this therapy, she would probably have a really hard time.
Christopher: I was going to say that sounds brutal.
Greg: It is brutal. She'd be sleepy and probably suffer from a very low mood temporarily, but very quickly, the quality of her sleep would improve dramatically. During this therapy, she would continue to track her sleep. Let's say she'd been tracking it for two weeks before and now, she would look at her sleep over the course of each week of this Bedtime Restriction Therapy. As somebody who has sleep maintenance insomnia, she would pay particular attention to her sleep efficiency.
Typically, what a practitioner would do to help this person is look at average sleep efficiency and if that sleep efficiency for the one week period is 85% or higher, Sally would then advance her bedtime the next week by 15 minutes, so instead of going to bed the next week at 2:00 a.m., she would go to bed the next week at 1:45 a.m. She would then record her sleep for the next week again and if her sleep efficiency remains at 85% or higher, the week after that, she would advance her bedtime again by 15 minutes. So you can imagine a situation in which after a period of ten weeks or so or let's say 20 weeks, she has now advanced her sleep. She has eight and a half hours of time in bed each night and her sleep efficiency remains 85%, so she's gone from spending ten hours in bed with 60% sleep efficiency, spending eight and a half hours in bed with 90% sleep efficiency and she feels dramatically better.
So she's gone through that suck period, but she's emerged the other side sleeping better and experiencing all the beneficial consequences of that too. If you don't have sleep maintenance insomnia and you don't want to go this route them something that you can learn from this regardless of your sleep difficulties is the importance of bedtime regularity, which I've touched on in our brief conversation at the start. That is one form of Bedtime Restriction Therapy and that would typically be implemented in conjunction with a practitioner.
But also, there are online cognitive behavioral therapy programs for insomnia such as Sleepio which will guide people through this process too typically after an introductory period of educating people about the importance of sleep hygiene and so on, but I know that the NBT listeners are very well versed in most of those things.
There is another form of sleep restriction therapy that's used, but it's used less commonly and it's typically used for sleep onset insomnia specifically and it's called Intensive Sleep Retraining. It hasn't been studied as widely, but so far, the results suggest that it is impressively effective. What this generally entails is first, depriving somebody of sleep entirely for one evening or having them dramatically restrict their sleep, so perhaps they spend three hours in bed instead of spending eight hours in bed, what this leads to is a very strong urge to sleep the next evening. That evening, the person would typically go into a sleep lab and what they would do is around the time that they would typically go to bed or perhaps slightly earlier, they would practice falling asleep and do so in a series of 30-minute cycles. In the first 20 minutes of these cycles, they would try and fall asleep. If they fall asleep then the person overseeing the night would wake them up after three minutes or so of sleep. They would then stay away until the beginning of the next 30-minute cycle and then they would repeat that, so they've got these cycles going on over and over again over the course of 24 hours or so, and because they're 30-minute cycles, this would give somebody about 50 opportunities to practice falling asleep. In this way, it's a very condensed form of practice.
Christopher: Worse than the first thing.
Greg: Yeah, it is. The difference is though that this is, of course, a couple of days and this is used for sleep onset insomnia, people who have difficulty falling asleep as opposed to staying asleep although it probably would help people who have sleep maintenance insomnia too. Just to touch on the results of this, to pick one study, the first study that looks at this after that period of practice falling asleep, the participants were allowed two nights of recovery sleep to try and catch up on some lost sleep and then they track their sleep for the next couple of weeks. They found that during that time, they fell asleep more than 30 minutes faster. They spent about 30 minutes fewer awake each evening and they also slept about one hour longer on average during those two weeks. Interestingly, they followed them up six weeks thereafter and some of these benefits were maintained up to that point in time, so this is an example of a very short-term intervention, which is extremely effective for a particular type of insomnia. It's not necessarily something that I'd recommend that people try at home --
Christopher: Well, that was going to be my next question.
Greg: Yeah, but with that said, there is a wearable device named Thim, which is a thumb-worn smart ring and it uses vibrations to wake people up from sleep and it guides people through this Intensive Sleep Retraining. I haven't seen any published literature on that device, but I know that it was awarded an award for being very promising new sleep technology by one of the big bodies in sleep a few years ago, so it certainly seems to be very highly regarded and that's something that people who have difficulty falling asleep can look into.
Christopher: Okay. Can you say the name of the author and the year of the paper? Because Elaine does a really fantastic job of rounding up all the citations and linking notes in the show notes so people can look at them.
Greg: Yeah. I think that it was in about 2011 and I want to say that the senior author's name on the paper is Lack. I think his first name is Leon. It might be Leon Lack.
Christopher: Okay. Well, I'm even more impressed by the fact that you're obviously not looking at the paper as you talk about it.
Greg: No, no, no. That's just memory.
Christopher: Okay. To go back to the regular sleep restriction therapy, what would you have someone do with the extra time after the normal bedtime? I feel like if I was to try and do this, I would get second wind and by 2:00 a.m., I'd be like, well, fuck it. I'm just going to go right through.
Greg: Yeah. That does raise a couple of points. One of them is in the very unlikely event that you try Bedtime Restriction Therapy and by the time that you plan to go to bed, let's say it's 2:00 a.m. in that first instance and you're not actually sleepy then you shouldn't go to bed. You should still wake yourself up and get out of bed at 8:00 a.m. the next day as much as that will suck. That's one thing to mention.
The other thing, to answer your question, is I think people should do things that they find relaxing during that time and they should probably do something in relatively dim lighting, but it is a struggle that people face, knowing how to spend that time. I think it's worth people contemplating how they can frame this positively. They have more time awake each day. That gives them a longer opportunity in which to do everything they want to get done. So in the same way when people go through the digital declutter, they feel that they have more time on their hands all of a sudden. People often experience this during this particular restriction therapy too and it can cause people to start to reevaluate what's important to them and perhaps take up new hobbies too. People are generally going to be inside at this time, so they often end up doing things like spending significantly more time reading. I think if people do end up working later in the night, which is certainly a viable option then it's important that they still start to unplug and wind down perhaps half an hour to an hour before their planned bedtime. The same sleep hygiene rituals that people are recommended regardless of their sleep issues still apply here, but with the extra time in your hands. It really depends on how you want to spend it and what you want to learn, but I would certainly consider trying to pick up a new skill or maybe finding out more about something that you've had a longstanding interest in. Maybe you could start an online course, for example. You go to Coursera and you could learn something that you wanted to be more knowledgeable about for years, but have never found the time to get to.
Christopher: You know what? It's funny you should say that because I live in Central London and I've almost wanted to learn how to play the drums. I'm kidding, of course. I have always wanted to learn to play the drums, but I'm not sure that's a very good thing to do.
Greg: Yeah. If you live with others too then it's probably not going to go down that well if you're banging away the drums, your bongos, at one in the morning.
Christopher: You know what you should do instead? You should support Josh on Patreon and then get access to his Ukulele for Beginners course. Maybe that would be something better although you'd still need a blue light filter for this. Maybe you just do some unguided practice on the ukulele at that time.
Greg: There's one more thing that I should mention while it's on my mind, Chris, and that's during the restriction therapy, there is a limit to the short amount of time that somebody is advised to spend in bed. Let's say in a very rare circumstance, somebody gets four hours of sleep on average each night, but they have an eight-hour sleep opportunity, so the sleep is 50% efficient. In that case, they shouldn't give themselves a four-hour sleep opportunity. The lower threshold is probably something like five hours, so if you find out you are actually sleeping four hours a night then I would not go below five hours a night.
Christopher: Okay. That's important. Let's talk about mindfulness. Can you tell us how mindfulness might help with insomnia? Maybe you should start by defining mindfulness. It's a word you hear a lot, but sometimes you might not know what it means. I know sometimes I'm a bit confused about what it means.
Greg: Yeah. I think a lot of people are, but the central premise of mindfulness really is that if people can cultivate greater awareness of the present moment and be more self-compassionate, so don't beat yourself up about things as much as you do necessarily and to not be too attached to outcomes, so to accept things as they are. In the case of insomnia, this could be somebody really focusing strongly on what they think the negative consequences of sleepless are then what can happen is somebody can learn to reflect on things as they are and instead of reacting, they can learn to insert a pause and then shift their stance such that they can respond adaptively and they have a greater range of options at their disposal rather than just having a knee-jerk response to their circumstances. In this way, it can help alleviate mental and physical distress, and this is very relevant to insomnia because if you look at people who have insomnia then they often have all of these maladaptive thoughts and behaviors too. Maybe, for example, they have very fixed thoughts about sleep and they try and force sleep as well. They put a lot of effort into falling asleep, which problematically actually ends up working against them and makes them take longer to fall asleep.
They tend to also be very attuned to sleep-related cues. As a random example, if you show a picture of a bed to somebody who has insomnia then they will have greater physiological arousal in response to that particular image. Using this mindfulness-based approach can be very helpful with these people by helping them to reframe their thoughts and also just better attend to their own internal bodily cues because what often happens is people who have insomnia will end up doing things like going to bed at a fixed time because they think, "It's 10:00 p.m. It's my bedtime. I should go to bed at this time." The problem is they're also prone to hyperarousal, so maybe they have a racing mind at that time and there's no way that they're going to fall asleep, but they think, "I need to go to bed now because it's bedtime." What ends up happening is, as we discussed in the previous podcast, they start to create the association between their bed and wakefulness and they reinforce that association.
By engaging mindfulness, people can better attend to their internal cues of sleepiness so they'll only go to bed when they do actually feel sleepy. Also, they can learn to maintain a state of equanimity in the face of fatigue. If, for example, you get used to meditating when you are a bit sleepy then you're going to train that particularly well. Through all of these different mechanisms, it's likely the beginning of regular meditation practice will help the majority of people who have insomnia. I, of course, think that meditation is a good thing for people to do, almost irrespective of their circumstances. It's been showing to have positive effects on so many different health outcomes.
With that said, many people, I think, consider mindfulness as some sort of New Age [0:22:09] [Indiscernible], but that's not really what it is. Part of that arise, I think, from the way that it's discussed in the media and the way that maybe meditation courses have been developed and people use apps and so on now, but if people can go through a rigorous meditation training program then I think that they only stand to benefit really. So the question really is how do you get going with the mindfulness practice? There are, of course, lots of different ways you can go about that and perhaps the best route would be to do an in-person meditation retreat or perhaps just regular sessions in person, but for many people, that's not practical. For example, that's not something that I would do on a regular basis because I have lots of other things to attend to and it's not something that I would do given that I can meditate in my own time as I wish. So for me, I have pretty much always used guided meditations.
My gateway into meditation was about five years ago when I read a book by Mark Williams about meditation and then shortly afterwards, I read Jon Kabat Zinn's book. He's got multiple books, but I read the best known of those. Then after that, I started eventually using apps and I began with an app called Insight Timer, which is free. It has huge amounts of content on there and it's a bit of a safari tracking down some of the better content, but it does have some nice features on it too such as meditation timers and so on. Currently, I use Sam Harris' Waking Up app, which Chris, I think you have some experience with too. I really like it because of the secular approach that he takes, and also, I just think that the lessons are very insightful. I think the quality of the content is excellent, but I know that it's not for everyone, so it really is a question of trying different things and then seeing what works for you.
One thing to mention is the majority of research that's been done on meditation in recent years has focused on mindfulness specifically and there are of course different types of meditation, transcendental meditation and so on, but given the nature of the science today, I would nudge people towards mindfulness meditation as opposed to some of the other types.
Christopher: Yeah. Do you think there's a certain irony in the idea of meditation in an app? Maybe the thing that's causing the problem is also delivering a solution. Do you think that is a possibility?
Greg: Yeah. I think there's a massive irony there. I think related to that, it's a really good idea for people to go through periods of time in which they don't do guided meditations, so maybe you use your app intermittently.
You could, for example, use your app for a month to take you through those guided meditations. I think that certainly initially when people are learning the ropes, they should be doing guided meditations, but then once people begin to develop some of those mindfulness skills, they can transition away from them and periodically unplugging from the apps, I think, is definitely a good idea. Maybe you alternate one month-long blocks in which for one month, you use the app, and for next month, you don't. That's just one example of how you might structure things.
Christopher: Yeah. I see guided meditation as a tool for reducing environmental mismatch. It's like the barbell. It's something that we need to do because we've become misaligned with the environment in which we evolved.
Greg: Yeah. Ultimately, of course, people's goal should be to be more mindful regardless of what they're doing. I think people make this dichotomous distinction between their meditative practice and the rest of their lives and what you should be trying to do over time is make that transition between your mindfulness practice in the rest of your life more seamless and try and make everyday objects in your life object of mindfulness.
I had a great discussion with a guy named Marko Lepik who is a meditation teacher. He's got a website, a company named EQversity and he's just a fantastic guy, so people should go and check out his work. He was talking with me about the idea of, for example, using your mobile phone as an object of mindfulness and this is really hard to do, of course, but if you think about stimulus control of behavior then maybe you get a notification on your phone and that leads you to reach for your phone. It's so easy to be reactive to some of these digital devices now, so I think that it might be particularly valuable if people can learn to make some of the more problematic devices objects of mindfulness, which is a hard thing to do.
Christopher: I really like Russ Harris' definition of mindfulness. I was reading an article by him over the weekend. I've read all of his books actually at this point and they're all fantastic. There's one called The Happiness Trap. There's another called The Confidence Gap. They're all centered around this evidence-based technique called ACT. Russ defines mindfulness in a variety of different ways, but they all basically come down to this, paying attention with flexibility, openness, and curiosity, so it's just noticing. It's like what Ellen Langer said on the podcast many moons ago. Noticing is good for your health. I feel like little kids are really good. You maybe haven't experienced this yet, Greg, but kids are really good at forcing you to notice little things because they're super curious. They pick things up off the ground and they show it to you and you're like, "Well, that's just a leaf. What do you want me to say?" and then you look at it and you're like, "Oh yeah, you're right. That is interesting." That happens all the time.
Greg: Yeah, and the ACT therapy is another of the so-called third wave therapies of which mindfulness is one, of course, and the articles here do actually link to one of Russ' resources. This takes us to another key component of this metacognitive or thinking about thinking model of insomnia and that's the importance of your values in your life. What can happen in insomnia is that people start to lose track of their values. If we, for example, consider somebody who feels like because they've been sleeping poorly of late, they need to spend more time in bed to catch up on the sleep that they lost the previous evening then maybe in the evening, they forgo some sort of social obligation that they previously committed whereas if you have them sit down for an hour and consider their values in a systematic way then they perhaps rank spending time with their loved ones and being a good friend or being a good partner or being a good brother as being as high as anything else. For that reason, it's very valuable for these people to go through exercises in which they do reconsider their values. There's an exercise called Life Compass, which I link to which can help people with that, but there are various other ones too. I know that Simon likes the bull's eye exercise too, which is also in the resource that I link to. I think if you have insomnia or if you just want a fun exercise to try and get you back on track if you feel like right now you're not quite being true to yourself and living your life as you would like then going through those is a really good place to start.
Christopher: Yeah. It's really helpful to stop thinking in terms of black and white. You listen to all these podcasts -- you listen to Matthew Walker talk about all this cool stuff about sleep and then you think that you're a bad person because you're not doing anything. "I'm not doing any of that."
"I should probably be paying attention." It's really, I think, helpful to get away from this idea of is it good or bad and towards the ACT model, which is, is this helping me live according to my values and a more rich and meaningful life? Maybe it doesn't affect that at all. Maybe you can stay up until two o'clock in the morning watching Netflix and still live a rich and meaningful life, but probably not, right?
Greg: Yeah. I think that it's a real problem among people who are very interested in health because they so often develop an unhealthy obsession about health-related things such as their diets or their physical activity or their sleep. If I think about the people who strike me as being among the most healthy people that I know, none of them is obsessed with health. I can consider my brother -- I've got two brothers, but my brother was a couple of years older than me. He drinks too much and he goes out regularly. He burns the candle at both ends. He works very hard in the city and so on, but he has a really rich social life. He's got a girlfriend who he's been with for years, who he loves dearly, and he's a really healthy guy. He's 32, but he -- no, he's 31. Sorry, Marcus, but he looks like he's about 25. He does everything wrong, but at the same time, it works very well for him and I think that part of the reason for that is that he's not too fussed about this stuff and he knows what's really important to him as a person.
Christopher: Right. I've heard this many times before though like it was okay until it wasn't okay. I hit my 35th birthday and suddenly, I hit a wall and I couldn't do that thing where I went out after work and drank five pints of Stella Artois and then got the underground home and everything was okay the next day.
Greg: Yeah. I hope that's not the case with him, of course, but yet there could be an element of that certainly and time will only tell whether that's the case.
Christopher: Okay. Well, let's talk about sleep for athletes. Are they a totally different sort of human?
Greg: No, they're not a totally different sort of human, but with that said, athletes are, of course, a very mixed group of people and the types of sleep difficulties that they face do typically tend to cluster according to the types of athletes that they are. If you look at sleep in athletes in general then the prevalence of sleep difficulty seems to be quite similar to people of the same age from the general population, so maybe a third to a half of athletes report poor quality of sleep, for example. The difference is that lots of these people are very focused on trying to do everything right when it comes to their health. Many of them probably have very good sleep hygiene now and they're still experiencing some sleep difficulties, so it's probably useful to touch on some of those different difficulties according to the particular types of athletes.
I think there are two main things to consider when it comes to training and those are the timing of training and the load of training. First, focusing on timing, timing is really a problem if it overlaps with the athlete's habitual sleep timing. Unless you are an individual athlete who has tight control over your own schedule when you train and so on, you've probably experienced difficulty with this before. Maybe you're a rower and you're on the water in the early morning and you have to wake up to an alarm for that. Maybe you're a sprinter and you have a coach who works at nine to five jobs so you can only train in the evening, but you're an early chronotype and you find that hard because your training finishes at 8:00 p.m. and you then have to eat and of course travel back home and so on, and you end up staying up later than you otherwise would've done.
In these instances, the solution that I would recommend for most people is shifting their sleep timing. The most important cue in shifting the timing of your sleep is your patterns of exposure to light and darkness respectively. If, for example, you're the rower and you want to shift your sleep earlier then you want to expose yourself to more bright and blue light containing light earlier in your day specifically within the first couple of hours of waking up. If you're awake and the day has already begun, the sun is out, in the first two hours after waking up, try to spend at least half an hour outdoors.
If the sun isn't up at that time then you can use a light therapy lamp and you want to get one that emits at least 10,000 lux and you want to also sit quite close to it. Again, sit quite close to it for half an hour or so. Then at the opposite end of the day, you want to systematically reduce your exposure to light in the evening too. If you're trying to shift your body's clock earlier and hence the time you go to sleep earlier then you probably want to be particularly systematic about reducing your exposure to lights in the evening. That, of course, entails all things that we've discussed before. You can wear a blue light blocking glass at that time if you so desire. That'll probably give you a slightly stronger stimulus than you would otherwise get in your ability to advance your sleep timing, but then there are two other things to consider really.
One is time of exercise. I'm assuming that you're already doing exercise early in the day. There's been some very interesting work published this year by Shawn Youngstedt and what he's looked at is the so-called phase-response curve for exercise, which just describes how the timing of an exercise stimulus relative to the timing of a person's internal or biological day influences that person's circadian rhythms. What the study showed is that if people go through moderate treadmill exercise at different times of day then they can shift the timing of their body's clocks. So specifically, if somebody who has a relatively typical chronotype -- so they're neither a morning lark nor a night owl -- exercises at about 7:00 a.m. then that will help them shift their body's clock earlier, but interestingly, if they exercise between about 1:00 p.m. and 4:00 p.m., that also tends to have that effect too, so exercising between 1:00 p.m. and 4:00 p.m. likewise will help them shift their clocks earlier. Exercising in the evening between about 7:00 p.m. and 10:00 p.m. would help that person shift their clock later.
Interestingly, one way by which exercise seems to do this is by increasing the sensitivity of the person to the phase-shifting effects of light exposure. What that means is that exercising outdoors at that time in the first two hours after waking up will definitely help you shift your sleep earlier too. The other thing for these people is being particularly vigilant of caffeine consumption. Caffeine tends to delay circadian phase, but also reduce the pressure to sleep or waking really late during wakefulness. If you do those things, more light in the first two hours after waking, less light in the final two hours before your planned bedtime and being more strict about your caffeine consumption, preferably temporarily cutting your caffeine consumption entirely then you should be able to shift your timing at least 30 minutes earlier per day, but again, I'd still suggest that you only go to bed when you're sleepy. Of course, to shift your sleep later, you basically want to invert that, so you're going to reduce your exposure to daylight from the first two hours after waking up. Maybe you stay indoors and you keep the lights on at quite a dim level, or if you're outside, you wear sunglasses then evening exercises will help shift your clock later and you probably want to increase your exposure to bright blue lights in the two to four hours before bedtime. You wouldn't increase your exposure in the 30 minutes before bedtime because that will interfere with your ability to actually then fall asleep. That's exercise timing.
The other thing I've mentioned is training load. If you look at how athletes sleep during periods of increased training load then quite often, their sleep will tend to fragment. There's been some nice work on this recently. [0:38:59] [Indiscernible] who is well-known on Twitter for producing very nice infographics did a nice study of this a few years ago. He looked at the effects of three weeks of overreaching in triathletes. Overreaching entails an increase in training loads and there are two broad types. One is nonfunctional overreaching in which performance declines. The other type is functional overreaching, which improves. Anyway, for three weeks, he had triathletes go through a 30% increase in training load and what they showed was that half of the athletes became functionally overreached, so they were performing better, but they were experiencing this overreaching. At that time, they had an 8% drop in sleep duration and a similar drop in sleep efficiency too, so their sleep tended to break up. In recent years, some people have been starting to question whether you can use sleep as a proxy of overreaching and overtraining per se, but it's difficult, of course, to identify whether it's a cause or an effect, but what this comes down to is better balancing training load with recovery.
If you've gone through a new training cycle and you have all these new exercise stimuli and your sleep is temporarily suffering then you can do two things. You can either reduce your training load in conjunction with your coach or you can try and be more meticulous about your recovery from the exercise, and both things have the potential to help you out. This also brings us on to nutrition. I know, Chris, that you've done podcasts before about things like Relative Energy Deficiency in Sport or REDS and this is very relevant to sleep too because I think one of the issues that people face during this overreaching or overtraining even is reduced energy availability and certain athletes seem to be particularly prone to this, but if that's the case then it's really important to try to do what you can to eat enough to support your training loads. If you can consume more calories than you are currently then that's probably likely to help you sleep at this time. Again, you don't want to have a giant meal late in the evening because that will probably interfere with your sleep, if anything, but if you can increase your energy intake a bit earlier in the day then if you're currently going through a phase in which your energy availability is a bit lower then it should be that you're likely to sleep better as a result of that.
Christopher: Do you see a danger here of combining some of the things that you talked about already on the podcast? Maybe I'm an overreaching triathlete and there's a relative energy deficiency. I know I'll just try the Bedtime Restriction Therapy.
Greg: Yeah, you don't want to do that. It's a really good point and I think people need to recognize that things like Bedtime Restriction Therapy are stresses as is low energy availability. The problem, of course, is I think some of the people listening to this are probably the types of people who work very hard during the day. Maybe they're CEOs or whatever and then they spend their free time hammering away on the treadmill or putting in mile after mile on the bike. Maybe they compete recreationally in triathlons in their spare time. This is the type of person who needs to be really careful of adding one stressor onto the next. There are also incidentally the types of people who will occasionally dabble in things like prolonged fasting. Just consider this in the context of your entire life and definitely be systematic about the change that you make. I think sometimes it makes sense to make multiple changes at once particularly if they're small changes, but if you're making a very large change such as Bedtime Restriction Therapy then you probably want to almost control for the other variables in your life so that you only change Bedtime Restriction Therapy and then see how you respond to that.
Christopher: Yeah. I think another thing that's quite likely, at least I know from working with clients -- and this is true for myself as well actually -- is that when you eat a minimally processed diet and you put your hypothalamus in an environment that allows it to regulate food intake, there's a tendency towards undereating. You then go train hard and you're eating tons of vegetables and meat like eating is going to become a part-time job and at some point, you just have to start liquidizing shit. You just can't get in enough calories to make the training benefits happen. That, I would say, is the main thing I see.
Greg: Yeah. White rice and honey become your best friends.
Christopher: You've got to pick your poison. Ice cream, I know, is some people's.
Greg: Yeah. I've experienced that myself before. I know that when I first transitioned to consuming more Paleo-type diet, I just found myself prone to undereating. I'd eaten quite a lot of food just to maintain my body mass. I got very lean and I looked good, but I also felt quite tired at times because I just wasn't eating enough. Now, I quite regularly eat things like white rice because I can eat a lot of it and it doesn't fill me up nearly as much as the equivalent number of calories from sweet potatoes.
Christopher: Can you talk about the intensity of the training and its effect on circadian rhythm? We just assumed that all training was equal there, but I know from personal experience that that's not true. For example, if I race cyclo-cross and the race starts at 1:30 in the afternoon, which by your definition, should shift my day, it should advance it, right? Is that the right word?
Greg: Uh-huh, yeah.
Christopher: But the intensity of that 60-minute period is such that I know I won't sleep well that evening whereas if I start earlier in the day -- and it doesn't need to be that much earlier.
I know I sleep much better, but if I was just going out for a ride with the dogs then my heart rate is not going to go above 140. It doesn't matter. I could do that at seven o'clock at night and it wouldn't have any impact on my sleep.
Greg: Sure. That's a really good question and there are a few things to mention. One is that nobody has systemically looked at the effects of varying the intensity of exercise on the degree to which the exercise shifts circadian phase. It could be, for example, that that is a dose response relationship such that higher intensity exercise of a fixed duration more potently shifts circadian phase, but we don't know that at present. If we consider the example that you mentioned there then it wouldn't surprise me if in this hypothetical example you do actually shift your melatonin rhythm a bit earlier with that exercise, but because the exercise is very depleting because it is a potent stressor, you might also increase arousal and increase your core body temperature for a long period of time afterwards. You'll have a variety of effects on things like inflammation also and all of these things might lead you to experience heightened arousal in the evening, so even though your circadian phase has shifted earlier, that increased arousal is now offsetting your ability to fall asleep that evening.
Christopher: Right, so people use this term "wired and tired" and I think it is appropriate. "I'm so tired. I don't want to deal with myself. I could barely direct myself off the couch, but at the same time, I can't get to sleep."
Greg: Yeah. If there were three words that summarized insomnia, that'd probably be "wired and tired".
Christopher: Yes. I guess this really highlights the need for what we've been calling the NBT-validated learning. So rather than relying on some randomized control trial of male collegiate athletes, you find some metric and then you notice with flexibility and curiosity and openness exactly how that particular workout is affecting your sleep and then you refine like okay, I did that workout at 7:00 p.m. That seemed to have an impact on my sleep, so maybe I should maybe go do the morning session.
Greg: Yeah. I think that's absolutely right. To go back to this example, I think there are a few other things that are probably at play too. One is that if this is a competition then you would anticipate that competition in advance and you probably would've put it on a pedestal. If it was very meaningful to you then that would probably have interfered with your sleep. Also, you'd be so aroused on the day of competition that that would interfere with your sleep that evening, so that would probably be one factor. Another might just be bodily discomfort, so if you really, really test your limits and you experience some pain thereafter or maybe you're cramping in bed that evening, whatever it might be, then all of those things are likely to disrupt your sleep too.
Christopher: Yeah, that's my favorite when I finish the cyclo-cross race, and that is I just have to lie down on the floor for ten minutes. I know that I've left it all out there if I have to lie down for ten minutes. If I can ride around and cool down then I'm like, "Oh, did I actually really try my hardest there or did I not?"
Greg: It's your barometer.
Christopher: That's my barometer, yeah. What else did we miss? I feel like there was another major topic that we were supposed to cover here.
Greg: Not really. I suppose the other thing to mention is just if athletes are very heavy, so imagine for example that you're a lineman in your football team then that is likely to predispose you to certain sleep issues. So in general, the heavier you are, the more likely you are to experience obstructive sleep apnea, which maybe affects something like 5% of the population. It's a disorder in which the upper airway occasionally collapses during sleep and that tends to temporarily lead to low levels of oxygen in your body and that increases activity in the sympathetic branch of the autonomic nervous system. If you control for things like body mass then people who have obstructive sleep apnea are predisposed to health problems such as type two diabetes over time. It is an independent risk factor for various issues, so if you think that you might have obstructive sleep apnea or if other people witness you temporarily stop breathing during the night, for example, then you should probably seek expert help for that.
The other thing that this type of athlete might face that would interfere with sleep is concussion. In contact sports in recent years, people have become more and more aware of some of the detriments and consequences of that, and also just how pervasive it is and how underdiagnosed they often are too. Concussions are often very bad for sleep as you could imagine, so it could be that --
Christopher: Well, initially, they might be good. You might be unconscious, but [0:50:03] [Indiscernible].
Greg: I think being unconscious and being asleep is sometimes somewhat distinct, yeah.
Christopher: I'm joking, of course.
Greg: That's a consideration for these people too and that really comes down to managing individuals and being responsible both as an athlete, but also if you're a coach involved in those sports then as a coach too. The other thing that we didn't touch on is travel because that's of course something that athletes often face. Travel brings a couple of difficulties. One is just the travel process itself. Travel often leads to travel fatigue, so even if you don't fly across different time zones then you're probably in a confined environment for a period of time. Maybe you're inactive. Maybe you experience dry cabin air at that time. Maybe your teammates are eating poor food and you don't have great food choices with you. Coping with this for the most part is a matter of good planning and making sure that you take food with you, arranging comfortable stopovers if possible, and breaking up your prolonged periods of sitting with some physical activity too.
There's of course also jet lag and jet lag itself is a very big topic. I don't really think that we can do it justice today, but we certainly can touch on a couple of the key strategies that people can use. First, your patterns of exposure to the light-dark cycle are the most important thing in helping you get over jet lag faster. Simon actually alerted me to a website named Jet Lag Rooster which is really helpful in identifying how you should shift your patterns of exposure to light and darkness according to the nature of your trip. On that website, you can just enter your origin and your destination and whether you're trying to adjust your body's clock in advance or not and so on. It will tell you when to expose yourself to lots of light, so at those times of day, you want to get outside in daylight, if you can. Otherwise, you want to be in a very brightly lit place, and when to avoid light exposure too
Let's take the example of me flying to the West Coast of the US. That would be an eight-hour time difference. If I stay up very late at night there then I might actually enter the phase at which if I expose myself to lots of light, that would actually start to advance my circadian system which runs contrary to my goal of delaying it so that I can resynchronize with any time zone. If that's the case and you're trying to stay out of daylight, but it's daytime in the new place then that I think is when blue blocking glasses really come into their own. The other strategy that's very helpful to get over jet lag faster is taking melatonin. You don't want to take too much if you're trying to get over jet lag as quickly as possible because what you want is you want a very strong, sharp pulse in melatonin, which will then act on its receptors and can quite potently shift the timing of your circadian system and that shift is additive to the effects of change in your light-dark cycle, so by using melatonin and changing your light-dark cycle in conjunction with each other, you can shift your biological clocks faster than you otherwise would be able to. Also, if you exercise at the time at which you should be exposing yourself to lots of light then that will likely have a greater effect still. If you take one milligram of melatonin at the time recommended by Jet Lag Rooster then that will likely help. You want to take conventional melatonin. Don't take the time release stuff because that has a longer half life and it will have a less potent phase-shifting effect on your body's clocks.
The other thing to consider is your diet. As I mentioned in the article, the quality of plain food, of course, isn't fantastic for the most part and for that reason, if you're somebody who can go through a fast without it being an excessive stressor for your body, I think that during plane travel, that's a prime time for you to go through an extended fast. If you don't want to do that then I would just think about the times of day that coincide with mealtimes at both of the time zones. Let's say, Chris, that I'm going out to see you on the West Coast. In that case then the time in the UK coincides with breakfast in California, so what I would do is I would wait until dinnertime in the UK and then concentrate most of my calories for the day around dinnertime.
Then I would probably wait until the next day in the US to start eating meals on US time, and that first full 24-hour period or the first full day after an overnight sleep in the new time zone, people should fully shift their mealtimes to the new time zone. That will help synchronize the clocks in many of their body's tissues with the new time zone faster. So diet, light exposure, and melatonin, potentially exercise too, are all things that people can use to expedite re-entrainment to a new time zone and get over jet lag faster.
Christopher: Okay. Am I right in thinking then that the general principle that we're trying to achieve here is that you want to minimize the job, right? So if I'm flying from San Francisco to London, it's an eight-hour time difference then ideally, I would start advancing my circadian rhythm before I travel so that by the time I get to London, it's not this huge eight-hour jump.
Greg: You could do that. I think practically, that's quite hard to achieve when you're trying to shift your body's clock and you're in a time zone that you're used to, so you're exposed to light at certain times of day. I think if people are trying to perform at their best and they're trying to do that at a competition after, let's say, a single day in the new time zone and the new time zone is several time zones removed from their own time zone then it makes sense to start to try and shift their body's clocks before traveling, but if they're not trying to fully synchronize in the new time zone -- so let's stop talking about size for a second and just say that you're a businessman and you're flying across six time zones. You have one meeting. You're there for 48 hours and then you're returning home. In that instance, you're not really trying to synchronize your body's clocks with the new time zone. What you're trying to do is just support your performance during the daytime so that can entail things like consuming low dose of caffeine at regular intervals during the day and then maybe supporting your ability to sleep well at night. If you use hypnotic agents, so sleep-promoting supplements or perhaps even drugs, then that's the one time that it does make sense for some people to use those. Obviously, some sleep drugs are indicated for certain sleep problems, but for most people, I would suggest that they stay away from them.
Christopher: One thing I'd also like to add is that I think a lot of people don't realize how easy it is to take food through airport security. We've been doing it forever. I don't think we ever really stopped. Julie will prepare a bunch of food, cook everything. She'll cook a rib eye like a tri-tip or something and will take all of that along with a bunch of cooked vegetables and cans of sardines and nuts and all kinds of things through security. You just put it all in a big cooler bag with some ice packs and usually it gets checked like it's pulled to one side and they go through it with a swab or whatever, but we never lose anything, so I don't really know why people subject themselves to the food that's available at the other side of security.
Greg: I think it's quite dependent on the country though. I know for example --
Christopher: We've been around the world. We've never had anything taken from us, not even a can of sardines.
Greg: My friend, Ali, makes biltong from time to time and he gave me loads of biltong shortly before I went to the states earlier this year. I tried to get it through US customs and they were having none of it, so they stole all of my tasty meat.
Christopher: Oh yeah. Well, there's that. You're right. You're totally right. If you're flying back into the US then yeah, you're going to have problems getting through customs with a bunch of plant material for sure. Yeah, I wouldn't show up to try and import a bunch of food, but while you're in the air, you should be able to eat, right?
Greg: That actually reminds me of flying to somewhere in Ecuador a few years ago and we got off the plane. There was a sign asking passengers whether they were bringing microorganisms with them.
Christopher: Yeah, trillions of them.
Greg: Exactly. Oh dear.
Christopher: That's amazing. Well is there anything else we forgot? At this point, I should make it clear that Greg wrote a series of articles that I will link in the show notes for this episode. Also, if you're on my mailing list, if you've been to the front page of the Nourish Balance Thrive website and you've somehow got onto our mailing list, which is not hard to do, then I will of course be emailing out the links to these articles, so maybe go back and check your email because you probably had the links to all of the articles by now, but I'll also link them in the show notes.
One other thing I would say is that if you've done all this already and it's not working and you still can't sleep then it might be a good idea to get some labs done. We'll look inside. We'll measure some stuff. We'll fix some problems and quite often, that leads to improved sleep, although I have to confess we don't always know the mechanisms.
I can't explain to you exactly what happened when I found your B12 deficiency and I fixed that and suddenly you started sleeping. I have no idea what the mechanism is. Please don't ask me that, but we have seen it happen. It's not a coincidence. Okay. What's the best place for people to find you online?
Greg: I am on Instagram and Twitter @gdmpotter. I'm also on LinkedIn at the same extension and that's about it.
Christopher: Okay. You've mentioned before that you have various speaking events. What's the next one coming up?
Greg: I actually have one this weekend and --
Christopher: So that's going to be gone by the time I edit this.
Greg: Yeah. What do I have coming up? I'm in London this weekend. I'm in Moscow next week. I'm in Mexico, so that might be after this is out in Mexico from October 18th to 20th in a place called Guadalajara, which I probably just butchered the pronunciation of.
Christopher: No, that sounds right to me. I'm not going to try and pronounce it myself, but that does sound right to me.
Greg: I wish I had done Spanish at school. I'm in Helsinki on November 2nd I think it is.
Christopher: Okay. Could you mention the names of the organizations that are hosting you? Because quite often they have their content available for sale online afterwards, so maybe people could get access to the recording even if they miss the live event.
Greg: Sure. London this weekend is the Health Optimization Summit. Moscow next week, I'm not exactly sure on the name of it, but if you search for "Moscow biohacker" then I think it will come up. Likewise, if you search for "Mexico biohacker Guadalajara" then that'll probably come up, and then Helsinki is run by the Biohacker Summit folks, so [1:01:55] [Indiscernible] Arena and his Mötley Crüe, so really looking forward to all of those. This should be a lot of fun.
Christopher: That's awesome. Excellent! Keep up the good work! I'll hope to meet you in person one day soon.
Greg: Yeah. It feels weird that we haven't met in person, but likewise.
Christopher: Yes. Such is the nature of it like the Digital Nomad and the Health Entrepreneur, right? It's all about online, which is sad, but I'm trying to fix that. I'm trying to record more in-person interviews, so I'm sure we'll make it happen at some point in the future.
Greg: Good stuff. Thanks, Chris.
Christopher: Thanks, Greg.
[1:02:27] End of Audio