Better sleep toolkit

Yvonne: Is it already recording, Jo? It's recording. There we go. Yes, we've started recording. So it will be recorded, and it'll be uploaded and available later on the website. Yes, any questions that you've got, put them in the chat, or when Sophie's finished, feel free to stick your hand up and come off mute and Sophie will take you questions at the end.

Sophie: [Laughs] This is a team event.

Yvonne: [Laughs]. So I'll hand over to Sophie now. Enjoy, everybody.

Sophie: Amazing. Thank you so much Yvonne. And thank you everybody for joining. First question for you, I would be massively grateful if you could let us know in the chat if you have ever been to one of these sessions before. What do I mean by these sessions if you've never been to one before? Well, I've actually been working with Oscar Kilo for last couple of years, and we've actually done 12 different webinars. There are in fact 12 hours’ worth of sleep science that you could delve into should you so desire. Now, I appreciate if you have got a burning question you don't want to delve all the way through 12 hours’ worth of webinars, so today I'm going to make an effort to try and signpost more information where we've got relevant questions, relevant content, and I'll also tell you about another resource which you have access to – free access – which is an online programme called the Better Sleep Toolkit, which hopefully delivers all the information that you'll need in little bite-size five minute chunks, so I’ll tell you more about that in a moment.

But if I just skip back onto the webinar slide for a second, we have covered all manner of different topics. That doesn't mean that we always cover them in the right amount of detail, or that the question that you were particularly interested in was covered during that session. And the feedback that we very often get is could we have more time for Q&A. So we thought today the bulk of our time will be on Q&A. So if you have joined this with any question about sleep, now is your chance. While you think about what those questions are, I'm literally just going to give you five, 10 minutes of background, and then we'll delve in and see what is in the chat. And Yvonne is going to be my eyes and ears in the chat. So give me five minutes while you try and think about oh, what is it that you would really love to know.

And I thought I would just talk about a recent study that I saw in the press and try and translate it for you a little bit. Because we are bombarded now with messages about sleep; everybody knows that sleep is important. And I had a call from a journalist the other day who said, “I’ve found this, I've seen this study, and is it true that it doesn't matter if we don't sleep so long as we go for a run?” And I was on the phone, I was thinking, “This sounds a little bit strange.” And there was indeed a headline in the Daily Mail that said, “Going for a run can counter health risks of bad sleep, scientists say.”

So I did a little bit of digging to see where this came from, and there was in fact a study which was published in The European Society of Cardiology, a very reputable journal, which looked at the rates of mortality, the rates of heart disease and cancer in particular, amongst people who slept different amounts and also who did different amounts of exercise. And what they did is they took 92,000 adults in the UK, so the UK Biobank cohort, so very much relevant to us. And the first thing to look at when you see one of these headlines is, is the population relevant? Was it in 10 Taiwanese students who were 16 years old, in which case it probably isn't relevant, or is it a mass population, or is it shift workers, whatever. So in this case, 92,000 adults age between 40 and 73 years old. So if you fall into that bracket, this might well be relevant to you.

And what they did is they got people to wear an accelerometer, which is an objective measure of how many hours of sleep that you get. And they wore that for a week, and this was done back in 2013 to 2015, and then they followed people up over time and they put people into buckets based on how many hours of sleep they got. And they characterised short sleep as less than six hours, intermediate as six to eight hours, or long sleep as eight hours or more. So they were quite big buckets really, and especially given that we are recommended by scientists to get between seven and nine hours sleep every night. So those buckets were a little bit strange.

And then what they did is they also looked at how much physical activity people did. And again, they put people into buckets of low, medium or high. And what they were particularly interested in was whether people did the recommended amount of physical activity, which is – according to the World Health Organisation – 150 minutes of moderate to vigorous physical activity in a week. So 150 minutes, two and a half hours, over the week. And then they followed people up over the next 15 years to see who developed heart disease, who died prematurely.

And what they found is that if you just took everyone on average, there were increased risks of mortality for the short sleepers, so less than six hours, or the long sleepers, so more than eight hours. But when they delved into the data in a little bit more detail, and then they looked only at the people who did sufficient amounts of moderate to vigorous physical activity, they found actually no relationship with mortality. So in other words, if you are generally physically active, it seems to be protective against those cardiovascular and early mortality risks in particular. So it's genuinely interesting, it's generally protective. It does not mean that if you wake up early in the morning, the best thing that you should do is go for a run which is the angle that the journalist was trying to use.

This is about managing risk, and in the same way that if you smoke, or you eat an unhealthy diet, or you don't exercise will elevate your risks of illness. Not sleeping enough, or potentially sleeping too much, may well increase your risk of illness. So I'm going to just delve a little bit deeper into why this relationship might be. You know, why is it that exercise seems to mitigate against some of the effects of poor sleep. Well, I think the easiest way to think about this is to think about all of our automatic processes like our heart rate, and breathing, and blood pressure are constantly in flux. We say that we are either in a fight or flight mode, or in a rest or digest mode; these autonomic processes are called our autonomic nervous system.

And at any one time we're a little bit more fight or flight, or a little bit more rest or digest, and we ideally need a little bit of a balance between the two. We need occasional stresses in order to activate the system otherwise we just get bored, but we also need time for recovery. And so when we get stressed, the balance obviously tips towards fight and flight. So the same thing happens in zebras, and it's almost a little bit more obvious when we think about a mammal. Let's say zebra spots a lion. The amygdala switches on the fight or flight stress response. So the amygdala is this little almond shaped bit in the middle of the brain. I've honestly never seen an a zebra amygdala, but I imagine it's quite similar to a human amygdala, and it kickstarts this stress response.

And what happens is we increase our heart rate, breathing rate, it floods glucose into the bloodstream firing us up for action. It also increases inflammation. Inflammation is an immune response which is almost to prepare us for injury. So the blood starts to coagulate, we’re getting ready to get eaten or to have to run away from a lion. Now when the stressor goes away, we start to activate the rest or digest system. So in that case, we switch off the increased heart rate, blood pressure and so on, we're able to dial down the inflammation, and we focus on digestion, muscle repair, all the good stuff in life.

And one of the most important impacts of sleep deprivation is that it alters this balance. We know that even one night without sleep and your amygdala basically gets trigger happy. We become more likely to activate that fight or flight stress response. The smallest thing, the smallest irritation can start to make us feel tense and under pressure. And if you have that feeling before bed, you know you’re tense, your muscles are activated, you're feeling anxious, your heart rate is raised, it's very, very difficult to fall asleep. So a lot of people will get into this cycle where they're not sleeping enough, they become more stressed – more what we call hyper-aroused – and find it very difficult to switch off.

So why would exercise make a difference? Well, in some ways exercise does all of this as well. Exercise is a stressor, but because it's a very specific stressor, you know, you are moving your body in response to a particular trigger – you know, you've decided to go for a run or jump on a trampoline, whatever it is – the moment that you remove that trigger, the system goes back into rest or digest. It's a very obvious transition. You're either exercising or you're not. And when you're not, you are recovering, and it actually helps to switch off the stress response.

So if you frequently are short of sleep and you tend to have this hyperactive system, regular exercise is one of the things that you can do to switch off the stress response and transition into recovery. So there is no doubt whatsoever that exercise has all manner of wonderful effects, lowering inflammation, boosting mood, boosting serotonin, endorphins which make us feel good, it helps to repair damaged brain cells. And the best exercise is probably regular moderate to vigorous physical activity, so stuff that start to increase your heart rate. But quite frankly, any exercise is going to be good.

Strength and conditioning we know becomes increasingly important as we get older. We should all be lifting heavy stuff over the age of 40 to stop our muscles deteriorating. So exercise is awesome, I am not going to deny that, but the reason that I was a little bit twitchy about the journalist perspective is because sleep does so much more for us than simply looking after our stress response. And actually, if we’re not sleeping well, we’re at all sorts of risks which are both physical, cognitive, and emotional. And just by going for a run, you can improve your mood. You cannot necessarily cancel out all of these other impacts of sleep loss, in particular the cognitive impacts, lack of concentration, inability to respond at speed, those things that are actually linked to accident risk, particularly if the nature of your work involves a lot of driving, for example.

So I'm not knocking exercise, absolutely do it, but don't feel like just going for a run is going to replace all the wonderful benefits of sleep. So yes, that was all I wanted to say about that particular study. If you would like to know how to improve your sleep, I'm sure we will talk about lots of things today. Yvonne, are we starting to get any questions come through, because I can stall this if we want to go onto questions, or I can carry on.

Yvonne: There’s a couple of questions so far, do you want me to read them out for you?

Sophie: Yes, let’s start with that, and then we'll delve back in.

Yvonne: So, yes, Alison's asking about trying to sleep off nights. “Do you benefit from simply resting and lying there if you can't sleep or wake up in the middle of the day and just can't get back to sleep?”

Sophie: Really great question. Do you know what, I'm going to – I feel like I want to want to see you, I want to see Alison. OK, so yes, when you come off nights, do you get a benefit from just resting, absolutely you do. I think one of the problems, and actually one of the reasons that I wanted to talk about this fight or flight stress response is that when you've come off a difficult shift, you have had adrenaline in your system. You've probably had cortisol, particularly if you've tried to stay awake during the night. The only way that your brain can keep you going at a time when your body clock is saying sleep is to charge up the stress hormones. So when you come off a shift, very typically you will be in a state of arousal.

So although you know you ought to sleep, your body is not really ready for it. So it's really important to go through a wind down in exactly the same way that normally we would recommend to parents to help their kids wind down after a busy day. So do a series of activities which will lower their levels of energy, slowly calm them down. So this might mean, for example, having a warm bath is a good one, listening to relaxing music, reading a book for half an hour. Yes, it means maybe slightly less sleep, but in order to get into a deep sleep you have got to switch off that stress response.

So just lying, particularly in a dark, a dimly lit room, what you don't want is to be somewhere that's very light and bright because that's just going to wake you up further. But listen to some music; give yourself maybe 20 to 30 minutes before you actually switch out the light, unless your eyelids are feeling heavy. A really good cue for am I ready for sleep is actually, are your eyelids starting to feel heavy. It's very difficult sometimes to tell if you've come off a night shift, it's light all around you, you’ve really got to make an effort to put your blackout blinds down, put my mask on, whatever. But yes, don't be afraid to take some time to wind down before you actually attempt to sleep.

Yvonne: Thanks Sophie. The next one is from Jo who's asking about the impact of poor sleep on other areas of health, for example, poor diet and weight gain due to overeating.

Sophie: Yes, this is a juicy topic, and I've got to say Yvonne, I'm quite tempted, I think we should do a whole webinar on sleep, and sugar, and metabolism, and weight gain because there's some really interesting stuff around sleep deprivation and the impacts that it has on your metabolism. But let me give you a little flavour in terms of the ways that sleep deprivation impacts behaviour. So those of you who've been to a webinar before may well have seen this, it's this summary of the fact that the amygdala gets more trigger happy when you're short of sleep and so your emotional balance is changed.

But what also happens when we're short of sleep, because the brain only has so much juice, only so much energy, and when you’re sleep deprived we prioritise our emotional responses, what actually happens is we start to down-regulate activity in the prefrontal cortex. So if you haven't had any sleep at all, it's almost like putting your prefrontal cortex – which is your centre of executive control, it's your logic, your rational centre, very good at strategic planning – it's a bit like putting it in a straitjacket. It's a bit like turning down the mute button. And what happens is you find it much harder to do things like problem solving, to make moral judgments, but also in particular your self-control tends to decrease, so you are less able to resist cravings.

And the really bad news is that when you are short of sleep, you also tend to have more cravings. So we know from studies where we've taken healthy individuals and deprived one of sleep and one kept normal, and then put them in an FMRI scanner, and you can show people pictures of different foods, and you show them a picture of an apple and they go “Yes,” and you show them a picture of a Big Mac and the reward centres in their brain – so this is the dopamine centres, the stuff that gets woken up by heroin – you show it a picture of a Big Mac and your dopamine centres go “Bing,” that is what you want when you're sleep deprived.

Because from the brain's perspective, sleep deprivation probably means you're in some danger, therefore you need to eat food, you need to consume calories. So even after one night with poor sleep, you typically consume about 250 to 300 calories more the following day unless you’re really paying attention, but you'll just have a tendency to snack a little bit more. So over time we know that sleep loss is often linked to weight gain. Not for everyone, some people would respond by going in the other direction, but it's certainly one of the factors that impacts on your food choices.

Yvonne: I love the way you explained that one, Sophie [Laughs]. The next question's from Brent who's asking about broken sleep. So how important is that? So for example, three sleeps of two hours versus one sleep of six hours kind of thing.

Sophie: So yes, OK, so sometimes this gets called polyphasic sleep, and if you read, if you go on the internet and you google “polyphasic sleep,” there are all sorts of proponents of different strategies for trying to hack sleep by getting two hours here, two hours there. I don't think that's what you're talking about, I think you're probably talking about coping with shift work, in which case, quite frankly get the sleep that you can. Shift workers are almost entirely chronically sleep deprived. On average, shift workers will get five to six hours of sleep, whereas most of us will be hopefully getting seven hours of sleep. So grab that sleep where you can.

What's the impact though of polyphasic sleep? Well you may have seen – may or may not have seen – this diagram before, which is – it's called a hypnogram, and it maps the different stages of sleep during the night. If, by the way, you’re not on mute, if you could mute, that would be marvellous. So yes, this is a hypnogram, so we go through different stages of sleep during the night. So if you plug electrodes onto the brain, you'll see these different stages, Stage 1, 2, 3, and then REM sleep. And during the course of a typical night when you have a whole seven hours of unbroken sleep, which I realise for many of us is like a myth, we cycle through all of these different sleep stages. And in the first part of the night you tend to get more deep sleep, and the second part of the night you tend to get more REM sleep.

Now deep sleep, very physically restorative; really restores your energy levels, growth hormone is produced, it’s really good for kind of making you wake up feeling energised.

[00:20:01 - 00:20:07 - Audio gap]

Yvonne: Sophie, just a second, you're on mute.

[00:20:09 - 00:20:15 - Audio gap]

Sophie: Oh goodness, I don’t know who muted me. Sorry about that. Where was I when I muted? Can you hear me now?

Yvonne: Yes, yes I can hear you now.

Sophie: OK. Oh good. Where did I get to?

Yvonne: Just going onto the second half of the night I think.

Sophie: OK. OK, great.

Yvonne: So talking about, yes, the stages.

Sophie: So second half of the night tend to get more REM sleep. So when you break up sleep into small – well, let's start with the seven hours actually. If you get seven hours of uninterrupted sleep, it's like a playground for your brain; it's able to switch in and out of the stages of sleep that you need. So let's say you've run a marathon, the brain is going to go “Right, we're going to prioritise deep sleep.” Let's say you've had a really difficult emotionally demanding day it might well be that the brain actually prioritises REM sleep. And if you have enough time in different sleep cycles, the brain will choose different amounts of sleep. Now, as soon as you compress sleep down, you are giving the brain less of a chance to swap from one type of sleep to another, and so overall, the likelihood is you are less likely to get everything that the brain needs. That's not to say that all the sleep that you get isn't worthwhile, but if you can sleep in long bouts it's going to be advantageous.

Now there are lots of examples where people have survived on micro amounts of sleep for a very long time. And here I'm thinking about transatlantic or transglobal sailors. I did some work with Pip Hare who sailed around the world, and she said that when she was sailing, typically she'd only sleep for a maximum of 30 minutes at a time, but she had to sleep, of course, very frequently. And after a couple of weeks of only getting very small amounts of sleep, the brain becomes more adept; you actually fall into deep sleep very, very quickly. So the brain is pretty good at compensating. So if you are forced to only sleep for two hours here an hour there, it's not perfect, but it's still going to be restorative.

Yvonne: OK, do you want me to carry on with some more questions?

Sophie: Yes, why not? Go on, keep them coming.

Yvonne: OK. So Julie's asking about these high caffeine energy drinks. So they're coming across more and more officers that are using them, understanding that they feel they need it to manage, but what's the best advice about the effect that they'll be having on their ability to switch off and sleep at the end of the shift?

Sophie: OK, I’ve got a little bit of a chart on caffeine here, so let me see if I can find my one on sleep pressure as well. OK, so I'll leave that one on there. Right, caffeine, how does it work? So as everyone knows well, having listened to 12 of these webinars, there are basically three things which influence the timing and quality of your sleep. One of them is your circadian rhythms – your body clock – and that thrives on routine. So when you are doing shift work that goes a little bit out the window, it's not your fault, it means you have to rely even more on the other two systems to optimise your sleep. So we've got circadian rhythms or body clocks.

The second one is sleep pressure. Now this is a lot more straightforward. The more hours you've been awake, the more you accumulate this chemical called adenosine in the brain which makes you feel drowsy. So for a typical person after 16, 17 hours awake, the amount of adenosine that you've accumulated from the activity that you've done is really starting to make you feel a little bit sleepy. The later you go to bed, the more sleepy you feel unless you block the effects of adenosine using caffeine. So what caffeine actually does is it blocks the adenosine receptors in the brain. So throughout the brain you've got almost imagine these little cups, and as adenosine accumulates, it comes into the cup, it comes into the receptor, sends a message through the neurones in your brain that says, “you’re sleepy.”

And what caffeine does – here’s my cup of coffee – the caffeine blocks the adenosine receptor in the brain, so the adenosine can't get in. So it fools the brain temporarily into thinking “there's no adenosine, you’re not sleepy.” Until of course the caffeine degrades, and then you’re left with all this stored up adenosine which then hits the receptors and suddenly you are exhausted, and that is the caffeine crash. So caffeine feels like it gives you more energy, but it's a temporary fix. It's a temporary delay because you are going to have to essentially pay it back later; that adenosine’s got to go somewhere.

And the problem is that when people get hit by a caffeine crash, typically the only thing they can think of to do is to consume more caffeine because they want to get rid of that really drowsy feeling. Now they do have an alternative; a short nap will also reduce the adenosine. Now I know that's not always plausible, specifically when you’re at work, you’ve got things to do, places to go, but really the only way to degrade adenosine permanently is actually to sleep to pay that sleep back.

The other problem with caffeine is that the more you drink, the more your body adapts and starts to expect caffeine, so you develop what's called tolerance. So over time your brain goes, “Oh, there doesn't seem to be a lot of adenosine around, so I'm going to produce more adenosine receptors.” And what that means is that you have to keep drinking more to have the same effect, so some of your colleagues probably started off with an occasional Red Bull, but then they realised they weren't getting the same lift, the same buzz from it. So maybe one became two, two became three, three became a couple of Monsters because their brain is now craving it.

So what are their options? Ideally you've now got to start tapering down, because if you suddenly stop drinking caffeine when you've been consuming an awful lot of it, because you have built up a tolerance and also a dependence, it will actually make you feel really sleepy. Now very often if you're used to having a cup of coffee at 10 o'clock in the morning or an energy drink and you suddenly don't, your brain is now craving it, so you start to feel really quite sluggish until you've had that caffeine. And some people get headaches and things as withdrawal.

So if you want to start reducing the amount of caffeine that you drink, I would taper down gradually over a week or two, and just switch out caffeinated for decaffeinated drinks. Now, as you will see from this chart, although energy drinks have quite a high concentration of caffeine, normal soft drinks also contain quite a lot of caffeine. So in a typical Coke can, 40 milligrams, Diet Coke is even slightly stronger, 42 milligrams, and that's about half as much as a cup of instant coffee, or a third as much as a Starbucks.

So the general recommendation around caffeine is that you shouldn't exceed – and this is going to make some of you smile – you shouldn't exceed 400 milligrams in a day, and that recommendation is based on six milligrams per kilogramme. So if your body weight is larger, then you can tolerate a bit more. But caffeine is a stimulant. As well as what it's doing on the brain it actually activates the sympathetic nervous system. So if you consume a lot of it, you're putting a bit of pressure on the heart, and if you’re vulnerable to that, then it can lead to arrhythmias and heart problems.

So yes, 400 milligrams or six milligrams per kilogramme is the recommended limit. See how they get on with that. My advice is to initially just start tracking how much you're drinking. Try not to change anything immediately, but just keep an eye on it, like make a bit of a tally of how much you are actually drinking, and then start to exchange caffeinated for decaffeinated drinks. That was a long answer,

Yvonne: [Laughs]. OK, next one, Pamela's asking about larks and owls. Are you just one or the other and is it difficult to change?

Sophie: Great. OK. I'm sorry, who did this question come from?

Yvonne: This came from Pamela Hudson.

Sophie: Pamela, thank you Pamela. OK, look, I've got a chart on this as well. I have got 500 in the background. So if some of you are wondering, “Huh, am I lark or an owl, I don’t know,” these questions that are on the screen will help to give you a bit of a clue. So some of us we wake up before dawn, the early birds, we wake up hungry typically, we probably don't function frightfully well after seven o'clock at night, and ideally we do our best work in the morning, whereas for others there are much more night owls. And I'm more of a natural early bird, I find it very difficult to imagine what it would be like being a night owl, where actually you really don't want to drag yourself out of bed before 10AM. Of course you can do it, but your body really wants to lie in.

But actually after nine o'clock at night is often when you do some of your best work, you're most creative, so this is a real difference. This is not just imagined. Some of us have a genetic predisposition to be early birds or night owls, but our behaviour does tend to reinforce it. What do I mean by that? Well, if you’re a teenager, the likelihood is that your chronotype – this pattern of sleep and wake times – is shifted more towards being a night owl. And this is a very natural transition. Hold on, let me see if I can find … da-da-da, just a moment. I definitely have a slide on this that comes from the Better Sleep Toolkit. Talk amongst yourselves.

Dum-da-dum-da-da. Oh, it's in week three. So there are four weeks of little, short videos in the Better Sleep Toolkits, and in week three it's all about managing your energy, and one of the topics is about how you transition your body clock from being an early bird to a night owl. And here I am going to find the information. Ha-ha, that's what I wanted. OK, so here we go. So the typical average person is an intermediate; they're not necessarily a night owl or an early bird. It's basically 25% will lean one way or the other. So the average person has a sleep-wake rhythm a bit like this, whereas a night owl really does peak later in the day in terms of their energy levels, and an early bird, as I said, starts off earlier in the day.

And in order to change this rhythm, the most reliable way of doing this is to use bright light. So this internal clock of ours is coordinated by a master clock in the brain. So we've got little body clocks all over the body, but there's this master clock in the brain which sets the timing for the day. And the strongest cue to reset the timing of your body clock is bright light. Now, bright light does slightly different things to your body clock depending on the time of day. So this does get slightly complicated, but if you want to know more, do try week three of the Better Sleep Toolkit, but I’ll give it a go.

Essentially, we've all got a daily rhythm, not just of alertness and appetite, but also of temperature. So here you can see an average person who goes to bed at 11PM, wakes up at 7AM, and their body temperature tends to peak around about 4PM in the afternoon, and this is called their Tmax, or their peak body temperature. And then they have the lowest body temperature usually about two to three hours before waking. So if they wake up at seven, then probably around four or five o'clock in the morning, that's the time when their body temperature is at its lowest.

So if you kicked off the covers in the middle of the night, like about four o'clock in the morning, you'll feel really cold, and then the body starts automatically to warm up in advance of waking so that when you wake up, when the alarm goes off, you're probably a bit warmer. So you can use the timing of your minimum body temperature, which is about four or five o'clock in the morning, this provides a bit of a pivot point in terms of our sensitivity to light. I will explain what I mean. If you get light in the hours just before your minimum body temperature, so let's say you get bright light or you're playing video games at one or two o'clock in the morning – and I'm thinking mostly of teenagers here, but maybe some of you – that will have the effect of delaying the body clock; it actually makes you behave more like a night owl.

If, however, you get bright light after your minimum body temperature – so this is the bright light at dawn, which for most of us at this time of year starts to become much easier, because five or six o'clock in the morning starting to get light – that actually shifts the body clock forward and makes you more like an early bird. So in order to become more like an early bird, it's about managing your light exposure. Food and movement also has a role to play, but if you get light right, that's going to have the strongest impact. So to wake up early, you want to set your alarm early, you want to get light as much as possible in the first hour or two of the day, and then you want to make sure that you dim the light and avoid bright light, particularly very late at night.

But when I said that your chronotype can be influenced by behaviour, if you think about the stereotypical teenage behaviour, because they're not tired, they don't go to bed, so they keep the lights on, they play computer games with all the other teenagers who are up late at night, and actually that has the impact of delaying their body clocks even further and making it even harder to wake up for school. So our behaviours will reinforce our body clocks. Again, that was quite a long answer, but hopefully quite thorough.

Yvonne: Yes, there's a couple of others.

Sophie: Oh thanks, Pamela.

Yvonne: Sorry, there's a couple of others that are linked to that. So we've got a couple of questions on – we've got lots of questions now, Sophie, so I don’t know if we'll get to them all.

Sophie: Right, I'll speed up.

Yvonne: We've got a couple on smart watches, but there's a couple of follow-ons from this one that I just want to cover first and then I'll come back to the smart watches. So Jo's asking about natural patterns, and Jo's an early bird but feels that it's a bit restrictive in terms of doing things in the evening, so should we change that? And then there's another one from Sue around circadian rhythm and maintaining good health, physically and mentally, when doing shift work, and is it important as you age? So linked to what you've covered, but …

Sophie: Yes, I mean historically probably it was great for a tribe to have some early birds, some night owls, you know it allowed the tribe to make sure someone was on watch 24 hours a day. These days it’s probably a massive social disadvantage to be a night owl unless you’re working nightshifts. And the reason that I say that is because for most people who need to get up for work at seven and be productive at work until say five or six o'clock, that fits the body clock time zone quite well. Whereas night owls are constantly trying to wrench their body clocks forward, and this we think can cause quite a lot of stress on the body.

So over time, when you look at the health impacts, if you compare early birds to night owls we know that night owls are more likely to gain weight, more likely to suffer from depression, higher risk of heart disease and stroke. And these are small risks, this is not “Oh my gosh, I’m going to get ill.” It's just one of those factors that can elevate the risk of these conditions, and it's probably because they spend a lot of time having to operate at times which are at odds with their body clocks.

Now, subtle changes from day-to-day are not a problem. We can all shift our sleep time, wake time by about an hour every 24 hours without causing any problems, but big significant shifts like shift work do put more strain on the body. So the more that you can do to help the transition by using light, but also I think probably perhaps most important when you're thinking about being a shift worker, because we can only shift by about an hour every 24 hours, when you suddenly go from days to nights, your body clock doesn't immediately shift. The reality is most of your internal body clock is going to still be on a daytime time zone, and you've still got to work at night.

Now you can do it, it requires a bit of adrenaline, it requires a lot more concentration, but what also happens is that your metabolism will stay on a daytime time zone. So one of the ways to protect your health is to try and still do the bulk of your eating during daylight hours and not to have large, particularly high fat, high sugar meals during that night shift because your body, your internal body clocks – your stomach, your liver –just aren't ready for it. So it's about avoiding unnecessary stress on the body. Certainly trying to sneak in exercise as we discussed at the beginning, that's a great way to de-stress the body, trying to sneak in regular exercise where you can, and also just giving yourself the gift of time to relax. I think for a lot of shift workers, because you're trying to cram in picking up the kids and doing this and doing that, there's so many things that you try and fit into a 24 hour period you end up not having an opportunity for rest and recovery. So yes, you can make these transitions, but they put stress on the body, so reward yourself with more recovery time.

Yvonne: Thank you. So we've got a couple of questions on smart watches now. How accurate are they? There's one person saying that they're lucky if it shows 15 minutes of deep sleep, and another one with similar, lots of light sleep showing and waking up to really vivid dreams and feeling a bit rubbish. So both similar questions.

Sophie: OK. I was looking for a slide in this that I can't find, but even if I just show this one. “Sports science experts urge caution in using wearables with teams.” The fact is that although tracking your sleep is helpful from the perspective of seeing how it impacts on your behaviour and perhaps making you a bit accountable, I think one of the great things about sleep trackers is looking at the time of waking, the time of sleeping, and looking for consistency because consistency rewards your body clock, so that's all good. But they're just not that accurate. The fact is that the only accurate way to measure sleep stages is to put electrodes on the brain and use what we call a polysomnogram. So any of these trackers – and I wear them as well; I'm interested in what they say, but I wear them to look at trends over time, not compare one night to another night.

So why are they useful? Well, the WHOOP band is – and lots of people have said, “Oh wow, when I consume alcohol the quality of my sleep goes to pot,” and that's quite good validation. But the fact is that although they're quite good at looking at overall sleep time, the amount of time that you spend in different sleep stages is not very accurate. This WHOOP, I think the latest validation suggested it was about 60% accurate, 60 to 70% accurate, so that's a bit better than guessing. But please don't read too much into that information. It's comparing yourself to somebody else when it's only 60 to 70% accurate is not giving you a really true measure probably of what's going on. But you can look at your own data over time and see what makes a difference for you.

Yvonne: OK. Can you explain the … This is from Gail Atherton; can you explain the difference or impact of sleep apnoea and sleep – now I haven't heard this word before – myoclonus?

Sophie: Oh, myoclonus.

Yvonne: Myoclonus.

Sophie: The answer to that is off the top of my head, no, I can't, because I'll have to look that up. But what I can do is talk a bit about sleep apnoea. So I’m just showing on a slide here. Right, the reason that I’m showing this is just to remind myself what's on here although I know you asked about sleep apnoea, and I've just shown you a slide on snoring, but the reason is when you look at this human being who is asleep – fast asleep – what's happening here is that their tongue is pressing back against the soft pallet, and the soft tissue in their throat, and the windpipe, and it's starting to obstruct. And what happens in snoring is that some of the soft tissues obstruct the airways, and as the air is pushed through, they start to flap and vibrate, and you get this [makes snoring sound] vibration sound.

In sleep apnoea, it goes a bit further and actually causes a slight blockage. So a lot of people who snore very loudly will have these brief periods where they actually stop breathing entirely. It's not dangerous because the moment that the brain notices that there's no oxygen coming in, it wakes you up, but it only wakes you up a little bit. So basically you come out of deep sleep into a lighter stage of sleep, so the snorer will go [makes a snoring sound], and there's this pause, and then after 10, 20, even 30 seconds, you'll get this [snorts] snorting thing. And that basically means that you've aroused out of the deepest stages of sleep.

So the bad news about sleep apnoea is that basically these brief periods of breathlessness occur repeatedly throughout the night, so you hardly spend any time in deep sleep whatsoever. So typically in sleep apnoea, you just find yourself after eight, nine hours sleep, being completely exhausted. So if it feels like you are getting like a good chunk of sleep each night, but you still can't keep your eyes open and you have any of these risk factors – so snoring, tiredness, perhaps somebody's told you that you pause or stop breathing during the night, perhaps you have high blood pressure, perhaps you are over the age of 50 and a man with a thick-set neck, these are all risk factors for sleep apnoea.

Now it doesn't affect everybody, and lots of people have mild sleep apnoea. If you have mild sleep apnoea, the good news is that just by avoiding triggers and managing other aspects of your health, this can be very helpful. So reducing weight, regular exercise, avoiding alcohol, avoiding being overtired, lying on your side, et cetera. However, there are some more heavyweight interventions. I was just looking to see whether I have my oromandibular advancement device. I think it's fallen off the table. Basically you can get something called a mandibular advancement device which pushes the jaw forward, and you get this fitted by a dentist if you are someone whose mouth falls open. You can also train yourself to breathe through the nose; that actually means that if you're not breathing through the mouth it's more likely that your jaw will be in an open setting, so some people find mouth tape or nasal dilator strips to be helpful.

The other thing that you can do is to use something called oropharyngeal therapy, or myofunctional therapy, and this is some exercises that you can do to strengthen the muscles in the soft palate and the tongue. And I don't think I have the link with me, but again, there is a whole chapter – a whole module – on sleep disorders in the Better Sleep Toolkit which will talk you through this. But if you are on the line and you want to know more about oropharyngeal therapy as a treatment for sleep apnoea, Google Vic Veer, an ENT surgeon in London who's got some quite good videos on that, or check out the Better Sleep Toolkit.

Yvonne: Wow, thank you. The next question is about water. Is water more just the more the better? Is it good for your sleep apart from the fact that you have to get up to the toilet lots of times through the night?

Sophie: Ooh, good question. I mean, too much sleep, if you have a full bladder that is not going to help with your sleep, and as we get older, we tend to have a more sensitive bladder. So my advice on that would be if you’re concerned, you're not quite sure how much to drink, you just start tracking it. Like try and – for most people it’s a good idea not to drink too much after, say, nine o’clock at night if you’re a regular sleeper. But if you wake up then feeling thirsty, it may be that you haven't had enough fluid, but it may also be because your mouth is falling open during sleep and that is one of the factors that can make you feel tired, it can also lead to bad breath. So again, this idea of practicing nasal breathing, and breathing through your nose during sleep, can actually be quite energising.

But as a first step, if you're thinking about, “Oh, to what extent does fluid affect my sleep?” just start tracking when you're drinking and how much you're drinking, and then try and change it, and see whether it has a difference, makes a difference.

Yvonne: That next one then is from Philip who works shifts but has heard that working shifts significantly reduces predicted age of death. So still working shifts, feels he gets sufficient sleep, but scientifically maybe not the right amount. Should he be considering a non-shift job for the sake of his health as he gets older?

Sophie: Really great question, and that's going to be a worry for everybody who works shift. Typically when you look at the studies, the increased risks of poor health are elevated by about five to 30%. Now that might sound big, but actually that's probably a lot less than say smoking. So it comes back to this idea of managing risk. If you generally have a generally healthy lifestyle, a good diet, regular exercise, you feel like you sleep well, and you personally don't feel overly fatigued, stressed from your job, I would personally suggest there's no reason to change it. You are going to start to experience symptoms if your health is being negatively impacted. And very often this starts to kick in when we are a bit older.

Like when you’ve been doing shift work for 15, 20 years, and Yvonne, I mean I look at you as someone who’s lived and breathed this, but it was interesting when we reached out to police officers and staff and we said, “Look is there anybody who'd be interested in helping us with addressing issues to do with shift work?” almost everybody who stepped forward was coming through saying, “I've been working shifts for 15, 20 years, I'm now in my mid-40s, and it's really starting to hurt.” It's at that point where it starts to feel difficult when you want to be more proactive about changing something it would be my suggestion, but Yvonne, I’m open to your thoughts on that.

Yvonne: Yes, I think it's just when it feels right for you. So I've got 27 years in, so I've worked shifts probably for the vast majority of 25 years, and it was starting to hurt and starting to get difficult for me to the stage where it was trying to sleep through the day. It wasn't doing the shift work, it was trying to sleep and trying to function properly, and that's when I knew that I had to do something about it because I was spending all my rest days trying to recover just to get straight back into it again. So it does get more difficult as you get older I would say. [Laughs]

Sophie: Yes, that tends to be the evidence from the literature that our circadian rhythms become less elastic as we get older. So we tend to be pretty good at bouncing back in our 20s and 30s, and some people will be more resilient than others. And there's a definitely a genetic predisposition to coping well or not coping so well.

Yvonne: A question from Ruth about jet lag, which probably goes back to some of the circadian stuff you've covered, and then I think we're nearly there.

Sophie: Yes, I would say on jet lag it is about using light, food, and movement at the opportune times, but there are some really good apps. There's an app called Time Shifter which I think you pay for, but it's not very much. But you can enter the flight times of your particular trip and it will tell you when to be exposed to light and when to avoid light. There's also a website called jetlagrooster.com, which is definitely free. If you go onto that, I – well the last time I went onto it I realised it'd been bought out by someone else, but if you put in jetlagrooster.com, you will find a link to a free – you put in your schedule, basically, and it spits out when you ought to have caffeine to help you transition.

Yvonne: OK, very last one then. Very last question because there's a few people talking about this in the chat bar.

Sophie: Yes.

Yvonne: Any tips for restless legs other than magnesium sprays or supplements? And then I'll let you just wrap up the session because we’ve got five minutes left.

Sophie: How does it go so fast? So again, restless legs; there is a video on this, on the Better Sleep Toolkit, you’ve heard me say this before. But idiopathic; for most people we don’t know why it happens. Definitely dehydration makes it worse. For any what we call parasomnias, these like weird things that happen during the night, they tend to be worse if you have poor sleep hygiene. So all the things that you would think of as being good for your sleep – so regular sleep-wake times, exposure to light in the morning, avoiding light in the evening, healthy diet – those are also going to help with reducing the amount of restless legs. But often iron deficiency anaemia is another thing that is linked to restless legs, so magnesium can help. There's a really good charity called RLS-UK if you want to have a look on there, there's some quite good advice from patients, from doctors. RLS-UK is the name of the charity and that will give you some more advice.

Yvonne: Thanks Sophie. Sorry, I did say that was the last one, but one final one. Angela wants to ask a question that she has submitted, but we obviously have missed and haven't picked that up. So sorry, Angela, do you want to come off mute and ask your question?

Sophie: Do.

Angela: Can you hear me?

Sophie: Yes.

Angela: Oh, brilliant. Hi Sophie. What it is, it's about fatigue really. Just really in a nutshell, I was having chemotherapy for 19 months, radiotherapy. I'm now back at work, everything's fine, but I'm on medication, Zoladex and tamoxifen, and the fatigue is just unreal. My sleep's amazing; I go to bed at 10 and I sleep right through till 6AM, 7AM. Sleep at night is amazing, but I wake up at 7AM and it's like I've done 10 rounds with Mike Tyson. I feel horrific, and as the day goes on, I just feel more horrific.

Sophie: OK, this is really tough. I'm so glad – first and foremost, I'm really glad [Laughs] that you've made such amazing progress. And honestly, the fact that you are sleeping well at night is really positive in terms of future recovery. We know that sleep is going to be so restorative for repairing damage, for giving energy, but I appreciate you are still tired. So when you are recovering from an illness, or if you are experiencing a chronic illness, the brain, the body craves more sleep. This is a natural reaction. So even if you're getting good quality sleep, it may well be that your body needs more of that deep restorative sleep to repair damaged cells.

So you are going to be wanting to think about like what tactical things can you use to energise during the day. And I know it sounds perhaps overly simplistic, but the more daylight that you get the better, full stop. Like the more you can take breaks outside – I don't know if you're able to work by a window – but bright light is really good for our mood, it's really good for our energy levels, and we know that it's really good for the quality of your sleep. And it seems perhaps a bit too simple to even say, but there was a study that came out very recently that I've referenced here that showed that for every hour of extra daylight that you get, there were significant improvements in particularly morning energy.

So that's what we're talking about here where you’re feeling like you can't get out of bed in the morning. Regular routines, lots of daylight, and then naps. I would have to say if you are able, if it's safe and possible to, do so, a 10 to 20 minute nap whenever you can. So if you have a short nap, 10 to 20 minutes, that should be slightly cognitively and physically restorative, but shouldn't be associated with the sleep inertia that can sometimes leave you feeling groggy afterwards. So just finding opportunities where you can just quickly close your eyes, have a little relax, and hopefully that will see you through the day. And it sounds like you're on the road to recovery. so hopefully this is only for a few months while you build your energy levels back up.

Angela: Brilliant. Thank you Sophie.

Sophie: Good luck.

Yvonne: Thanks Sophie. Well we're on 11:59, so last minute to wrap up before people maybe have to dip out for the next meeting.

Sophie: OK. So really – I know I keep plugging it, but honestly I have answered almost all these questions in the Better Sleep Toolkit. It's an online course. There are a whole load of things that people have said as a result of seeing the course that they're going to start to do differently. The challenge, I'll be completely honest with you, is getting people to actually use it. And what tends to happen is people sign up to it and then completely forget about it. And that's my challenge because I've got to create like nudges that people can use. Once you've created an account, you can actually access all of the content on an app called Kajabi, but very few people are doing that. So one of the actions that I am trying to take away is to actually put everything in an app that will come with push notifications to make it easier for people to remember.

But for the time being, it's still an online course. I would love your feedback. If anyone does use it, please come back to me, let me know what you liked, what you didn't like, because I want to revamp it to make sure that as many people are benefiting and coming back to the course and getting everything that they need to get out of it. So I will leave you with that, which is the signup instructions. But, wow, I can't believe that went so fast.

Yvonne: It did. Yes, it really did. So thank you, Sophie. Loads of questions there, but yes, as you say, most of them covered in the toolkit. So for those of you that weren't aware of them, or haven't visited before, do have a look at the at the online resources that are on the website. So thank you so much to everyone that's joined us today. Hopefully you'll keep an eye out for any future events and join us again, and also share the resources with your colleagues. Thank you.

Sophie: Thank you.

Angela: Thank you.