WHOOP Podcast - Understanding your circadian rhythm and how to prevent daylight savings from throwing your body off

Episode Date: October 28, 2020

WHOOP VP of Performance Kristen Holmes and VP of Data Science and Research Emily Capodilupo return for an in-depth look at how the end of Daylight Savings Time messes with your circadian rhythm. This is everything you need to know about how your body’s internal clock can be altered by even just the change of one hour. Emily and Kristen discuss studying the differences between daylight time and standard time (4:37), the rise in heart attacks after the clocks change (5:20), understanding your circadian rhythm (6:41), mental health challenges associated with the time change (8:22), sleep consistency (11:39), preparing your body for restorative sleep (16:01), light exposure (18:39), food and your circadian rhythm (22:23), vitamin D boosting foods (26:19), timing your workouts (36:09), and their key takeaways (39:22).Support the showFollow WHOOP: www.whoop.com Trial WHOOP for Free Instagram TikTok YouTube X Facebook LinkedIn Follow Will Ahmed: Instagram X LinkedIn Follow Kristen Holmes: Instagram LinkedIn Follow Emily Capodilupo: LinkedIn

Hello, folks. Welcome to the WOOP podcast. I'm your host, Will Amad, founder and CEO of WOOP, and we are on a mission to unlock human performance. We build technology, hardware, software, analytics. It's designed to help you improve your body, improve your health, change behavior. And you can get 15% off a W-W-M-M-M-M-E-D, if you use the code Will-A-H-M-E-D. We have an amazing amazing podcast for you today with Kristen Holmes and Emily Capulupo on daylight savings and how it affects your body. And first, I wanted to say that we've just made an exciting announcement that WOOP has raised $100 million in a new round of financing.

And so if you're interested about what that means for the company and how we're going to use those funds, you can read more about it on the locker, I can just tell you that for all the Woop members out there listening to this, I want to give you a big thank you. Thank you for being on this mission with us to unlock human performance. Thank you for believing in us. And we're going to use this capital to invest in your membership experience. So we're going to reinvest in everything around software and features and analytics

and just overall continue to make Whoop the best experience for understanding the human body. Again, if you want to learn more about the round of financing or how we're going to be utilizing this capital, please check it out at whoop.com slash locker. Okay, this week's episode, VP of Performance, Kristen Holmes, is joined by VP of Data Science and Research, Emily Capital Lupo, and they go deep on how the end of daylight saving time messes with your circadian rhythm. This is everything you need to know about how your body's internal clock can be altered by even just the change of one hour.

Emily and Kristen dive deep on the physiology and the science behind. at all and share their tips and tricks for how your body can avoid falling behind when we fall back this weekend. They discuss some astonishing studies showing just how negatively the time change can affect us. Heart attacks go up, car accidents rise, reports of depression increase. It's pretty amazing stuff. Why it's important to establish good sleep consistency. How you need to reevaluate your meal times as the clocks fall back, the importance of light exposure with much shorter days ahead, and the timing of your workouts and why exercising later in the day might not be as counterproductive as some have suggested. This is a great podcast, and without further ado, here are Kristen and Emily.

Hello, everyone. My name is Kristen Holmes, VP of Performance Science here at Woop. So excited to be back with the ever-so-talented vice president of data science and research, Mrs. Emily Capital Lupo. With daylight savings being a stone's throwaway, Emily and I wanted to take this opportunity to talk about the significance of a one-hour shift on our daily functioning and biological system and how we can, you know, use whoop data to better understand and hopefully mitigate, you know, some of the negative influences or impact of DST shorter days and just less light in general. So to ground the conversation, we're going to do just a quick overview of some of the most recent relevant literature. And, you know, honestly, there's there's

quite a lot of rigorously executed research on how daily semi-time impacts human behavior, the cardiovascular system, and mental health. So I think it's really relevant that we, that we talk about it. Emily, so what stands out to you in the literature as it relates to DST and why it is important for members to be aware of? Sure. So one of the biggest things that's, I think, important to think about with daylight savings time is that, you know, we think about it as like something that happens twice a year, but really it's that there's two different schedules that we're on at different points in the year. When daylight savings starts, we move our clocks forward an hour to get on to daylight savings time. And then what's coming up next weekend is that daily savings

is ending on November 1st. And so we're actually going to set our clocks back an hour to get off of daylight savings time. And so these two different time shifts have something in common, which is the one-hour time shifts, but they're actually very different because in the spring, you're coupling a time zone change essentially with the loss of an hour of sleep. And in the fall, coming up next week, you're coupling this one-hour time zone change with actually for most people gaining an hour of sleep. And so you see very different physiological impacts, and it creates a really interesting

case study, you know, looking at the shifting your clocks by an hour and what's the effect of changing your sleep by an hour. Yeah, it's kind of like this natural exposure experiment, you know, that that allows us to, you know, this like kind of unique opportunity to link health outcomes to like this controlled external event. Yeah, because a lot of the things that are affected by these pretty small changes in timing, you know, one hour time zone change, most people will just sort of absorb pretty easily. Maybe. Maybe. they feel a little off for a day or two, but it's not that disruptive, similarly with getting a bit more or a bit less sleep. But when you look at the data in aggregate, the Monday after

daylight savings, there's a Swedish study that showed that heart attacks increase quite significantly. And so, you know, the overall daily rate of heart attacks, like globally or nationally, is pretty low. But when you sort of look across the whole country, because we're all experiencing this weird disruption in our sleep together, there's a very measurable and statistically significant increase. And the good news for us, because we're coming off of daylight savings time on November 1st, is that November 2nd, we're actually anticipated to have a relatively low rate of heart attacks. And the belief is that that's the benefit of the extra hour of sleep. And so I think we're going to spend a lot of time in this podcast talking about the

impact of the disruption on your circadian rhythm, which definitely, you know, is real, but they're also in the fall in particular some really interesting benefits to the extra sleep that we're going to get. That study that you referenced, that took into account, I think I guess both Sweden and the U.S. did show some measurable health effects. Self-reported decrease in alertness. I would imagine that to be more true in the spring, but it was actually quite evident in the shift from daylight saving. So what? What's your take on that? Yeah, you know, I think a lot of that is the circadian effect.

Just to back up for a second, our bodies have an internal clock that sort of keeps track of days. And it's called our circadian rhythm. And it governs sort of most famously our sleep wake cycle. So sort of determines that like when we feel sleepy at night and it helps us feel alert throughout the day. And so whenever we change time zones, which usually happens because we're traveling, you know, your circadian rhythm needs to adjust to the sort of new local time.

What's kind of funky and interesting as an experimental condition about going on and off daylight savings time is that we change time zones without traveling. So you can isolate what's the effect of shifting your clock around from what's the effect of travel, which, you know, can be physiologically challenging for other reasons. So what I think's going on, you know, with the alertness is that we're sort of trying to be alert at a time where we haven't like trained our bodies necessarily to. to be alert. And so you see when your circadian rhythms get thrown off that all of our systems are sort of in this adjustment mode instead of in like that nice cruise control mode. But it is a

little bit more complicated in the fall than in the spring. For example, kind of similar to the heart attack study that came out of Sweden, there's another one that showed that traffic accidents are actually way up Monday after daylight savings starts in the spring and down the Monday. after daylight savings ends in the fall. And so, you know, I think arguably driving is a big daily test of alertness. And so the fact that accidents are down suggests that is not quite as straightforward, you know, even if like reaction time tests seem to suggest a disruption. The other thing that stood out to me a ton was just the fact that there were more emergency visits associated with mental health issues. So, you know, I think that's probably to do with,

again, when you look at an aggregate average, you know, not just literally the day after the change, but, you know, over the course of the few months after the time change, that really in the fall, losing this hour can actually be quite impactful on one's mental health. Yeah, that increase is not casual at all. There's a Danish study that showed an 11% increase in depression cases following the fall time zone change. Right. And that that effect sort of dissipates over, you know, a couple of months. But what I actually think is going on there, as, you know, this is not my original thought, as did the authors of the study, is that when we make that time zone shift in the fall, we make our nighttime essentially start earlier. And so there's something called sad or seasonal effective disorder, which is, you know, essentially depression that's believed to be brought on by the lack of sun exposure and sunlight. And so for a lot of people who work indoors, you know, they might not see the sun at all through their entire day. You know, the vitamin D in a lot of ways is a happy hormone. And, you know,

seeing the sun, you know, there's a reason why we sort of think of, you know, sunny days as being feel good days and all that. So you kind of very quickly take that away from people. Because if we didn't go on daylight savings time, sunset would gradually move earlier, but we sort of jerk it forward. by a full hour, and so a lot of people, you know, their mood state gets disturbed and then they adapt to it and there's different kind of coping mechanisms and stuff, but that like sudden change can throw a lot of people off. A really good thing to mention at this point is that if this is something that you're experiencing, it's really common and there are different treatments. So there are these things called happy lamps, which are essentially vitamin D lamps. You can put

them on your desk at work and it can stimulate a lot of the benefits of daily sun exposure for people whose like work environments wouldn't allow them to get sun exposure otherwise. Yeah. And I think that's such a great hack too for folks who are, you know, who work at night, you know, and are sleeping during the day. That can, that light exposure can be really powerful and help mitigate some of these symptoms that are, you know, potentially associated with a lack of light. We should mention those too. There's a really good study into. 2016 published in epidemiology will link to that, but just basically, as, as Emily said, you know, just talking about the depression in the month following this, you know, shift back

to standard. But some of the symptoms just for so folks can just be on the look at, you know, sadness, fatigue, hunger, you know, trouble sleeping are all, you know, signs and symptoms of the seasonal effective disorder. And we should mention that neither of us are medical doctors and, you know, definitely contact your doctors, you know, if you think that you might be. experiencing any of these things because even though it's sort of common and explained, it doesn't mean that, you know, it should be ignored. It can be like a very real thing for a lot of

people. So I wanted to talk, Emily, you and your team did a really cool analysis, just looking at the impact of sleep consistency in boob members. So that just, you know, would be really cool to kind of talk about what that, what's just sleep consistency in general. Obviously, this time shift as an alteration in your sleep wake time. And just showing the impact of that, I think, is kind of interesting. But just backing up and looking at sleep consistency generally as a behavior and how powerful it is, maybe we can kind of start there and then we can kind of back into ways to think about mitigating some of the, just some things that we can do in the next really five or

six days to kind of help ourselves with this time shift. Yeah, absolutely. And before I jump in, the research that Kristen's referencing came out in February. 2019. This was all self-published stuff, so it wasn't peer-reviewed, but is available at the locker at whoop.com slash the locker. And we'll link to that as well. Shifting our clocks by an hour is roughly equivalent to, you know, a sort of hit to whoop's sleep consistency metric of about five points. And what we were looking at in the research that we published last February was not specifically looking at your daylight savings at all or even time zone changes just when you change

your relative bedtime and wake time. And what we found is that changing your sleep consistency in that magnitude about five points has statistically meaningful impacts on sleep efficiency. So we expect you to spend more of the time that you're in bed awake. It also decreases REM sleep and slow wave sleep. And because of the hit to sleep efficiency, you're going to get less sleep overall. So one of the ways that you can offset that, of course, is just spending more time in bed

because you're going to have less of that sleep time actually be spent to sleep. And that's going to happen because one of the big benefits of our circadian rhythm is that it tries to anticipate our sleep wake timing and it starts to produce all that good sleeping hormones, you know, at the same time that it's warned, like this is when we sleep. And so when you change around your sleep time, you mess with that hormonal cycle. And so you're no longer working with it. You're kind of fighting against it. And so you're not going to have the same concentrations

of hormones when you do try and sleep. And so it makes it harder to sleep at all. And then when you do fall asleep, it makes it harder to get into those deeper, more restorative phases of sleep. And so, you know, this is kind of where a lot of this research, it gets a little bit complicated because there's a lot of things going on, right? So, you know, you might be getting sleeping less efficiently, but, and, you know, we shifted our circadian rhythms because of the time change. But especially in the fall, we're also getting a little bit more sleep, but we're getting less restorative sleep. And so I think that's why there are so many complicated effects. Some seem like benefits. Some seem like negative things. Some of them, like the

comment, Kristen, you made earlier about reaction times. seem to kind of go both ways. And I think that that's because some people are going to be more impacted by the benefit or the harm of daylight saving. So if you're more impacted by getting the extra sleep, you might experience these benefits. And if you're more impacted by, you know, losing the restorative sleep, disturbing your circadian rhythm, you're going to see more of the negative effects. And so I think there's kind of also this like spreading out of the typical experience immediately after the fall time zone change, which you don't see in the spring where it seems to be more just bad across the board. I mean, sleep consistency just generally. And I know we've been

talking about this for literally years because we observe it in our data. But I guess we just can't underscore enough like how important it is to allow your body to go to bed when it's naturally ready to go to bed. And being as in tune with that as possible because of all the down downstream effects it has on your system and your just your daily functioning. And Emily, in that research, it explained up to how many minutes difference in nightly average REM sleep? Yeah. So we saw that sleep consistency can explain up to a 36 minute difference in average REM sleep per night, as well as a 15 minute difference in slow wave sleep per night. I mean, that's crazy. Yeah, it's a lot. And, you know, I think what's so cool about it is that,

It's a behavior. And so it's something that's within our control, whereas, like, a lot of things that affect deep sleep, like how safe we feel in our environment or, you know, hormonal changes and these different things can be harder to immediately impact or even kind of entirely out of our control. But, you know, sleep consistency is a behavior. You can make an effort to go to bed at the same time every night and to try and wake up at consistent times and to not use, you know, every weekend as an excuse to totally throw off your sleep wake cycle. And if you do that, you're going to find that, you know, more of the time that you're in bed is going to be spent to sleep. And so you're going to not need to spend as much time sleeping,

which frees up time to do other things throughout the day. You're going to be more rested for the time that you do spend. You're going to get more slow-wave sleep, which, again, is the physically restorative part of sleep, more REM sleep, which is the mentally restorative part of sleep. And so you're just going to wake up feeling a lot better. And it's kind of one of those things that, you know, we see people before they get on whoop, they haven't really heard of or thought about this.

And, you know, those people who make this commitment and improve their sleep consistency start to sleep a lot better. And then you're going to find that your recovery scores the next day are going to be higher. So it's definitely, you know, a behavior that, you know, if we all just make small improvements, to sleep consistency. There's going to be immediate measurable benefits to having done that. Right. And a lot of, you know, setting ourselves up to be able to go to bed and wake up at consistent times, a lot of those behaviors that enable that are actually happening during the day. So wanted to kind of dig into to that a bit. Just, you know, this concept of

light being a really, really powerful cue that really dictates how we build. that sleep pressure, right? And, and the timing of all of that. So you mentioned, Emily, just, you know, exposing yourself to, you know, an artificial light during the day just to kind of wake up the body, number one, alert, you know, tell it that it's supposed to be alert. But how does that actually influence when we feel sleepy at night? So that exposure to light during the day. Yeah, light exposure is actually one of the most important, you can think of grounders of your circadian rhythm. And so while we think about it, like you said, is sort of something that impacts when we feel sleepy.

It's so much more than that. You know, it's also when we're feeling alert. And, you know, sunlight is a cue to our body. It's, you know, been a, you know, evolutionarily very reliable cue to our body that it's daytime. And so if you are having trouble getting up and going in the morning, especially, you know, in the winter when dark out in the morning, trying to get some sunlight exposure to sort of tell your body like not to be all groggy or whatever because you know you're trying to like still be physiologically in like a hormonal state consistent with sleep but to sort of show your body like oh it's daytime and then you know that's

going to kickstart the hormonal production for like daytime hormones and make it a lot easier to stay alert and so you know even something as simple uh and i think this is actually really important while we're all working from home so some of us might not have a reason between waking up and starting work to leave the house and to get any sunlight. But like to try and, you know, even if you just stand in a window, but if you can get outside and like take a couple of deep breaths and you obviously don't look like directly at the sun or anything silly like that, but like, you know, try and soak up a little bit of sunlight, it's pretty remarkable how little exposure it takes also just to like get things

like vitamin D. So you need to expose 5% of your body for five minutes to get like your daily dose of vitamin D. And, you know, that's another big thing that causes issues in the winter that we tend to get vitamin D deprived, which impacts sleep, it impacts mood. And it's been implicated in seasonal effective disorder, which we were talking about earlier. And our body absorbs most of our vitamin D from sunlight. You know, trying to give your body that sun exposure that says it's daytime now. You know, it might feel a little bit silly to go, you know, stand on your porch and take a couple deep breaths, but you deserve that minute. to kind of ground yourself and to expose your circadian rhythm to the sun.

And it actually has measurable physiological benefits in terms of aligning the circadian rhythm. Immunity, skin health, you know, mood, cotterine function, like all of those things are going to be influenced. I think, too, like part of it is just kind of rethinking your routine potentially, especially, you know, as we get into this, this timeframe where it is going to be potentially a little bit darker. And for folks who are actually working from home, you have maybe a little bit more flexibility, too, to kind of organize your schedule that will allow you to kind of get outside and, you know, take a walk at lunchtime where in an office environment, maybe you didn't have the opportunity to do that. But I think being, you know, really setting some intention around just this concept of getting the slight exposure can be really powerful. And just it will help you get on track faster in terms of dealing with. this shift in time. You can't underscore enough how important this light anchor actually is and how that influences your ability to kind of get to sleep and and also get into these deeper

stages of sleep. It's really important. Awesome. Okay. The other behavior wanted to talk about Emily is just this concept of fueling and the timing of when we fuel and how we think about that in the context of our circadian rhythm. So if you want to just kind of zoom out for a second and talk about that. And then we can get into just some of the details around, you know, what types of food can kind of help us, you know, given that we're, you know, not getting as much exposure to sunlight. The circadian rhythm, again, people tend to think about it as being about sleep. And people think about the disruption is that daylight savings causes disrupting sleep. But it's our whole circadian rhythm. And one of the things I think it's like somewhat

underappreciated is that the same way that our body tries to produce sleep-promoting hormones when it's anticipating sleep and that that's what helps us sleep better at night when our circadian rhythm and our sleep-wake schedule are aligned. It's the same thing with digestion. So we anticipate food at certain times throughout the day and we start to produce digestive enzymes and things in anticipation of receiving that food. And if we don't receive that food, our bodies can feel thrown off. And when we fuel at times when our bodies aren't anticipating it because they're not as ready

for that food, we don't digest it quite as smoothly. And to get it, the second part of what you ask you, thinking about ways to sort of help your digestive system, given that, you know, you might be sort of surprising it with food at unexpected times, you know, things like drinking more water, being more intentional about hydrating can be really helpful to kind of offset this timing thing. And, you know, one thing that's somewhat interesting about the circadian rhythm is the more regular we are with all of these things, sort of the more smoothly they go. But the more irregular we are, the more kind of flexible our bodies become too. And so people who are used to eating at really

erratic times are going to notice this much less than people who like take their lunch break, you know, at noon every day and, you know, have breakfast at eight every morning and all that kind of stuff are going to sort of notice it more because the more reliable that you've told, your body, your timing is, like the more thrown off it's going to be when you change that. So there's sort of like benefits to being super regular, but also those are the people who are going to be impacted the most. So if you don't notice any digestive symptoms related to the time zone change, that actually could be totally normal. And you're sort of one of those lucky people. But if you are noticing anything, you know, it's nothing to worry about too much.

it takes about a day for our bodies to adjust to a one-hour time zone change. So definitely not something we would expect to linger, but something you can kind of meaningfully offset or kind of alleviate some of that just by hydrating more and being a little bit intentional about how you're going to fuel for that first day or two after the time zone change. Yeah, and just generally, like I think about this concept of just auto-regulation a ton, right? because it's, it is this, your body's anticipating. And, and I think, you know, the degree that we can kind of anchor, you know, our fuel, our obviously, our sleep wake timing, exercise, we're going to

talk about in a minute, because I think that's another really stabilizing anchor that, again, our body can kind of latch onto. And then, you know, all the environmental cues as well. So it's, it's not, you know, it's not a million things, right? It's just kind of a few things. And if we can really stabilize these few things, then we're giving our body an opportunity to just do what it naturally wants to do and in sync with the circadian rhythm. So I think these are really powerful, as Emily said, like powerful kind of grounding forces that really help our body move through these disturbances in a more kind of efficient, you know, natural way. Okay, in terms of just foods. And again, you know, Emily and I are not nutritionists, but there is a lot of information

out there on foods that contain vitamin D that can kind of help us in this time where we do have less exposure to the sun and they can kind of, you know, help stabilize our mood and our motivation even to a degree if we can, if we just ensure that we're adding them in. So vitamin D foods. Yeah. So a good kind of general way to think about is vitamin D is fat soluble. And so a lot of fattier foods are going to be vitamin D rich. So think of like your fatty fish, like salmon, tuna, mackerel, and as well as, you know, a lot of dairy is vitamin D fortified.

So you'll see milk. Yeah, milk often like brags about like having added vitamin D in it. A lot of breakfast cereals are similarly kind of vitamin D fortified. And then if you can't. Tofu is a good alternative, right? If people can't tolerate dairy? Sure. You know, everything I have mentioned so far is not vegan-friendly.

So just kind of go on the vegan-friendly side. Or if you're, you know, don't tolerate dairy. Mushrooms have vitamin D. Soy milk, actually, instead of cows milk also has vitamin D. Oh, breakfast cereals. I mentioned those. But those are all, you know, excellent sources of vitamin D. We'd be remiss probably not to just mention, kind of since we're in just this fueling hydration

zone, caffeine, drinking it within eight hours of when you intend to sleep is not going to be helpful. So just putting that out there. Is there anything else with caffeine that you'd want to mention them? Yeah. So, you know, caffeine blocks our melatonin receptors and melatonin is our sleepy hormone that helps us go to bed. And so you want to have caffeine in the morning because it's going to help you, you know, inhibit any remaining melatonin. Again, the sleepy hormones. So it helps promote alertness. But closer to bedtime, it'll interfere with sleep. And the sort of somewhat tricky thing with caffeine is that it sticks around in our bodies for a very, very long time, as long as seven hours. And so, you know, you want to make sure that somewhere around 2 p.m.,

you're having your last cup of coffee, you know, because anything later than that, you should anticipate that it's going to impact sleep negatively at night. Right. And then maybe just the final point, just talk about timing of meals. Again, you know, your body is going to latch on to the regularity. Emily went through in detail just about the enzymes and the anticipatory effect. Let's just talk real quick about food close to bedtime because I think that is, you know, we've seen tons of evidence in our data that meals close to bedtime really do inhibit slow sleep and REM, you know, just a much more fragmented kind of experience, just talk a little bit about the physiology that we think might be going on there. And just as an aside, we're doing actually

some really cool research around this to try to understand this phenomena better. But what's kind of happening there, Emily? I think with anything, it's always really important. You know, we're going to talk about the average effect, which, you know, is on average negative. But there are a lot of situations in which it could actually be really beneficial to eat close. to bedtime. So for people who, you know, for whatever reason, have trouble getting enough calories in or very thin, you know, eating at night so that you have enough calories in your system to sleep can actually be super beneficial because if we're really hungry, oftentimes it's very hard to sleep or to sleep well. I'll add on just on that specific note that you want to try

to eat. What I've seen is, is, you know, working with, you know, athletes, tactical athletes who, to Emily's point, you know, need to get, you know, these extra calories are frankly just really hungry. The type of food they eat is important. Yeah. So the just, you know, foods that are high encasing protein, for example, or, you know, hydrolysis, grass fed, like collagen, glycine, like foods like that that are actually going to, that are really bioavailable and release slowly into the body, but don't are not super, you know, don't take a lot. of effort from a digestive standpoint. Yeah, no, that's a great point.

Sort of where I was headed is that you don't want to distract your body with other demands when you're trying to sleep. And that's kind of where your food timing can get in the way of sleep, but also where, you know, extreme hunger can get in the way of sleep because that's distracting as well. But when you give, when you eat like, say, really complicated foods that you now need to throw a lot of resources at digesting, that's an active process. And so, you know, when we're trying to, like, power down and put our resources into sleep, if they need to go into digestion, we're trying to multitask essentially. You want to be kind of intentional about what kind of foods you're eating.

You don't want to have, you know, really, really high glycemic index foods. It's going to give you that, like, blood sugar, crazy spike, which is going to be counterproductive for falling asleep. But if you're sort of uncomfortably hungry, you know, definitely eat something because that can get in the way of your. your sleep. And quality fats, you know, the short chain are actually like a pretty good energy source to sustain kind of the detox and recovery while while you sleep. So again, I think it's a lot of it is about like the quality. If you do need to eat it, it's, you know, ensuring that you're getting the right kind of foods. We'll definitely link to a little sleep cocktail that that we've seen and lots of other legitimate nutritionists have gloned on to as well. So we'll share that in the show

notes for folks who do need to eat prior to bed. What we've seen, a little combination that we've seen in the data be quite helpful, actually, for sleep. So we'll make sure to share that. Let's talk about exercise and the timing of exercise. And I think these are good just principles generally, right, when we're thinking about our circadian rhythm and trying to create this environment of auto-regulation. You know, exercise is another really big anchor. If we're thinking about this in the context of like one's chronotype, for example. I'd love to get your take. You know, is that a good way to think about exercise? You know, if you're a morning person, for example, or maybe actually if you're more of a more of a night owl, you wake up in the

morning, you know, exercise can actually like wake you up. It's not a good way to kind of think about it. And how does this relate to kind of circadian rhythm? Yeah, so a lot of the circadian rhythm kind of hacking stuff is about like trying to give your body a cue that just lets it know what you're to do because you think about it's like our bodies with the circadian rhythm it's like they try and be like really smart and anticipate what's going to happen and then warm up the engines right for whatever is about to happen and so you know if you only ever exercised during the day you can become a very strong cue for your circadian rhythm that says okay like the day's getting started let's do this and as you start to kind of exercise our bodies goes like okay we're definitely

done sleeping, right? This is different than just like getting up to pee and then we're going to go back to bed, right? And so our bodies can respond to that. And, you know, there's a lot of little things that we do throughout the day that let our bodies know what's going on. So, you know, we were talking a couple minutes ago about how, you know, our bodies try and anticipate meal times. So one thing you can do that's going to help your body anticipate the fact that your meal timing is thrown off is actually like cooking your own food because, you know, it's if you're used to like making your breakfast before eating it, you know, it's a very strong signal to your body that when like, you know, it's hearing and smelling all of the cooking sounds and smells that like breakfast is

about to follow. And so, you know, we can use as much as a timing cue that our body has learned from the circadian rhythm, we can override those with sizzling eggs on the grills cues and, you know, like all that those kind of sounds and smells and even like tastes you know as we're you know sneaking things along the way and so those can be really really strong cues and then on the sleep side things like putting on pajamas or you know being in your bedroom assuming you don't like also work there you know kind of do other daytime activities there and then obviously just sort of exercise you burn some calories you get tired and it's always going to be easier to fall asleep at night and then to sleep well when we fatigued ourselves during the day and it's harder to sleep well regardless of circadian

rhythm effects if you don't do anything all day because you have all this kind of unused energy in your body's underutilized right just that pent up end of the day energy yeah yeah so i think just like principally just paying attention to when you feel like exercise is most beneficial for you um you know it could be again giving that burst of energy in the morning that you kind of need just to like get yourself awake and or feeling like you kind of already have it done knowing that you know later in the day you might get you know he might be more tired and less less likely to do it you know other folks you know find like a midday run really energizing and and that's actually one of the big changes for me in quarantine has been you know I never worked out during the day

or at night because by the time I got home from you know the office I commuted to Boston you know did um uh it was i was just too too darn tired it was too late and had all sorts of you know family activities at at night so i would wake up very early and always work out but but now i've been working out midday and it's been just just been awesome you know i find myself really um you know it's it's like super energizing to me to kind of have this like midday run or or weight lifting session or whatever it is that i'm doing that day and then you know i find myself like really quite productive the next few hours, you know, as I kind of finish out my day. So that's been an awesome shift for me. And I wanted, you know, Emily, there is actually some pretty cool research

because a lot of folks really avoid, even though it feels really good to them, avoid these evening workouts. And there's been some cool research recently that that suggests that end-of-day workouts might not actually be so bad for a particular, you know, group of folks. I think the study was done on, you know, younger men. But it would be good. I think, to point that out. Yeah. So there's a really great paper that was published October 2019 out of Central Queensland University, which is a research group that we've done a lot of collaborations with, although we weren't

not at all involved in the study. And they showed that exercise before bed, specifically looking at about, I think, 90 minutes before bed, did not negatively impact sleep. And what, you know, I think was so great about this paper is there's a lot of, you know, of folklore around not working out four hours before bed. And this paper showed that it's not quite as simple as that. And, you know, it's important to pay attention to your own body and what you're sensitive to.

I'm sure there are plenty of people who are sensitive to exercise within four hours of bedtime. But I think what the paper shows is that most people can probably tolerate that. And, of course, you have to kind of weigh that against all of the practical considerations of, you know, if I'm not exercising four hours before bedtime, does that mean that I'm not exercising at all, does that mean that I'm, you know, waking up, you know, insanely early to exercise, which might mean that I'm therefore not getting enough sleep, you know, at some other time. And so I think, like, you know, one of the things I always want to be careful to do is,

is to balance, like, what's sort of physiologically optimal advice with what's practically actionable. And so, you know, like Kristen, you were saying, like you, you're having this sort of great experience exercising midday, but that's really only. been made practical by the current pandemic in that, you know, exercise at, you know, 2 p.m. wasn't all that feasible when, you know, you were in the office. And, and so I think, like, a lot of it, there's, we all have lives, you know, outside of, you know, just sort of hyper-optimizing for circadian rhythms. And so kind of need to think through, you know, what's physiologically optimal, but what am I weighing this against is, you know, the alternative no exercise, in which

case sort of exercising at an unoptimal time is probably better than not exercising at all, especially not exercising ever. But, you know, if you do have the chance or some flexibility in your schedule, you know, it is a good idea to kind of try out a couple of different times and see how your body reacts and how you tend to perform. Like I know there's some interesting research on like globally when elite athletes set records and most records are broken in the early afternoon, which suggests that like sort of on average, right, the sort of best time to have the best workout experience is early afternoon, but that's probably for most of us the least practical, especially during the week. And, you know, that research definitely does not

suggest that if you're like, you know, working out before work or after work, that you're not getting all the benefits of doing so. To sum this up, the best thing that we can do is really to establish really clear routines and behaviors, associated with sleep, wake timing, light exposure, fueling, and exercise. Those are kind of the big core anchors, right, that the body's going to respond to. Establishing routines is really going to help our body understand what to expect next, right? So enabling like this efficiency and, you know, which is going to have this incredible downstream effect.

Okay. So, Emily, just in the next five days before this time. change. Any recommendations on just, you know, kind of do we, you know, peel back our, this is that I've been doing in the last couple of years and just kind of start to peel back my time to bed, you know, by 10 minutes, which, you know, moves my dinner exercise. Everything kind of ends up getting like pushed back just slightly. And then by the time I hit the 31st, you know, I'm kind of pretty well positioned to kind of manage this change. So I end up waking up in, you know, I usually wake up around 5.56 o'clock. So end up because I'm kind of peeling back, you know, I end up in the right zone of time once this shift happens.

Yeah. So, I mean, I think you just said it all. But what you can do, and it's definitely, you know, physiologically supported what you just recommended is you sort of slowly start to shift your body onto the new schedule. And so instead of having this somewhat stark one hour time zone change, all at once. You have consecutive 10-minute changes, maybe over the course of six days, or you can do it over, you know, if you just want to do it over the weekend, you know, you could do it 30 minutes and 30 minutes. The smaller, the changes, the easier it is for us to just absorb it and not have any noticeable effects. And so, you know, I think this might be even more useful advice in the spring where a lot of us find it really hard to lose the hour of sleep, you know, sort of leave it to the listener to decide if it's worth it to them in the fall where most of us find it pretty easy, if not wonderful, to gain the hour of sleep. I think different people are going

to be differently interested in trying to hack this, but that is great advice if this is something that you know that you adapt to less easily. And it's also just, you know, we should mention great advice for travel in general. So, you know, going from, you know, Boston, to Chicago is the same physiological, like one hour time zone change is, you know, switching between daylight savings and standard time. And so, you know, if you want to kind of practice this hack next weekend when daylight savings starts, it can just kind of become a little bit of a tool that you have for actual travel as well. I always have to make a plug for the journal because I just think it's like the best thing ever. But you can absolutely track all

of this in the WOOP journal, you know, tracking what affects your sleep is, is really kind of where it's all at. So looking at, you know, the effects of light exposure, tooling and exercise, you know, and how those, you know, how that impacts the quality and duration of your sleep and the consistency, you know, these are things that you can, you can really start to understand with a little bit more clarity once you start tracking and you kind of start paying attention to your monthly performance assessment. You can kind of see, again, on average, how some of these behaviors might be influencing you. Yeah, that's such a great point.

We're going to just shift into winter with just a whole lot of grace and gratitude. And this has been great. Emily, thanks for all your wisdom and insights. Hopefully readers enjoy some of these nuggets. Let's do this. Awesome. Thank you, Kristen. Thank you to Kristen and Emily.

As always, amazing hosts on the Wooop podcast. A reminder, you can get 15% off. A-WOOP membership, have used the code Will Ahmed, W-I-L-L-A-H-M-E-D. Check us out on social at W-W-P-A-W-A-W-A-W-A-W-A-W-A-W-A-W-A-W-A-W-W-W-W-W. Thank you.