Feel Better, Live More with Dr Rangan Chatterjee - BITESIZE | Do This Every Morning to Boost Your Energy, Improve Your Sleep and Optimise Your Health | Dr Kristen Holmes #538

Episode Date: March 21, 2025

In our hyper-connected modern world, where we have access to artificial light around the clock, we’ve drifted far from our body’s natural rhythms. But what if reconnecting with these internal clocks could be the key to unlocking better health, more energy, and even a longer life? Feel Better Live More Bitesize is my weekly podcast for your mind, body, and heart. Each week I’ll be featuring inspirational stories and practical tips from some of my former guests. Today's clip is from episode 479 of the podcast with scientist and researcher Dr Kristen Holmes. Kristen is Global Head of Human Performance and Principal Scientist at WHOOP and a Science Advisor to Levels Health and Arena Labs. In this clip, we explore the world of circadian biology and she shares how reconnecting with our body’s natural rhythms could help us reclaim our energy and optimise our health. Thanks to our sponsor https://www.drinkag1.com/livemore Support the podcast and enjoy Ad-Free episodes. Try FREE for 7 days on Apple Podcasts https://apple.co/feelbetterlivemore For other podcast platforms go to https://fblm.supercast.com. Show notes and the full podcast are available at drchatterjee.com/479 DISCLAIMER: The content in the podcast and on this webpage is not intended to constitute or be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor or other qualified health care provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have heard on the podcast or on my website.

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with your first order. See all details at www.drinkag1.com forward slash live more. Welcome to Feel Better, Live More Byte Size, your weekly dose of positivity and optimism to get you ready for the weekend. Today's clip is from episode 479 of the podcast with scientist and researcher Dr. Kristin Holmes. In our modern world where we have access to artificial light around the clock, we drifted far away from our body's natural rhythms. And in this clip, we explore the world of circadian biology and Kristin shares how reconnecting with these natural rhythms could help us reclaim

our energy and optimize our health. Circadian rhythms and circadian alignment is the foundation of your house. And when that is not firing on cylinders, anything we attempt to layer on top of that is really just layering inefficiency on top of inefficiency. So, you know, any nutrition protocols that we're trying to deploy or any, you know, exercise, like in order to really capitalize on these other things that we're doing, the timing of when we're viewing light, when we're restricting light, when we are eating, when we are sleeping, when we're waking up, and when we're viewing light, when we're restricting light, when we are eating, when we are sleeping, when we're waking up, and when we're active, help and train our circadian rhythm. So the

timing of those things is absolutely central to our overall health longevity. Yeah. No, I love the way you put that. I've been a medical doctor now for 23 years and I'm always focusing on, for me, what I call these four pillars of health, food, movement, sleep and relaxation. One thing I've realized over the past, I would say at least a decade, is that if you haven't got the basic foundational pillars of health dialed in as well as you can, you simply don't know how many of your symptoms are just a consequence of that, right? So as doctors, we often will treat your symptoms and say you have this condition and you may do, but sometimes that's just a natural consequence of the fact that you are living in some sort of circadian misalignment.

So of course your mood is low. Of course your brain function isn't where you want it to be. Of course you're putting on weight, et cetera, et cetera. Like if I can dial that in with my patients, you often find that a lot of the downstream symptoms just kind of go away as a consequence. Yeah. I think that's beautifully said, of course. And it's not that we don't go wrong, but I think people, we think about sleep, for example, sleep doesn't have a circadian rhythm,

but it's an output of the circadian clock. So it's our daytime behaviors that dictate our ability to fall asleep and stay asleep and get that beautiful restorative night's sleep. We might talk about our sleep hygiene, which is very important, but unless our circadian rhythms are aligned, sleep is gonna be very difficult.

And I think that's one of the biggest problems in modernity. A lot of this is because we're living in a world where we have access to light 24 seven. And as a result, we're creating just a lot of this is because we're living in a world where we have access to light 24-7. And as a result, we're creating just a lot of stress on our system. And this manifests, of course, in things like our alertness and our ability to attend to the things that matter to us during the day, but it really, really impacts our sleep at night. I'd love you to explain what is a circadian rhythm and when our circadian rhythms are disrupted as they are for so many people these days, just shed a light on some of those consequences.

Of course, it will help you feel good and give you more energy and more focus, but there are some quite serious long-term consequences, aren't there, when we have misaligned circadian rhythms? Yeah. So circadian rhythms, very simply, are the physical, mental, and behavioral processes that are happening over a 24-hour cycle. And there's lots and lots of evidence in the literature that the consequences of desynchronized circadian rhythms, that is basically bypassing our natural internal preferences, which we want to try to match our natural internal preferences with the light-dark cycle.

That's like the most prominent cue to entrain our circadian rhythms and to create this circadian alignment. So for example, when we are viewing light at a phase of the natural light dark cycle that puts enormous stress on our body. So we know this as, you know, viewing light at night, for example, after the sun sets, right? Or not getting enough light in the morning

as the sun is coming up. So this basically confuses our system in that our internal clocks are become disorganized or don't quite know what to do. And this creates misalignment, right? And that creates stress on our system. So, and that stress of course manifests in very real ways, right, in terms of suppressing our immune system.

And we know that there is not a single mental health disorder that circadian rhythm disruption doesn't touch. So if we are chronically misaligned, our internal system becomes very confused. And this cellular miscommunication is really, I think, the basis of most disease and, frankly, aging. And our autonomic nervous system, our sympathetic branch of our nervous system is chronically activated. This leads to disease and aging.

Now there are other behaviors that help and train our circadian rhythm. So when we go to bed, when we wake up, we wanna try to align these behaviors with the natural light-dark cycle. So when we're supposed to be active and eating and sleeping, we wanna try to do that in a way that's aligned

with kind of these natural environmental cues. Are you saying that everyone has an internal rhythm that has presumably been set in some way based upon their lifestyle and the way they're living. But ultimately it is internal and our job therefore is to have external behaviors in our life that match that internal rhythm as much as we possibly can. With shift workers, it can be more challenging and we'll talk about that for sure. Yeah, that's exactly right. And you know, in all of the research that I've done over the course of the last four years for my thesis,

the one behavior that bubbles up and is predictive of physiological and psychological functioning is sleep-wake timing. The more stable it is, the higher levels of psychological functioning, okay? The more positive psychological functioning folks have, and the stronger the physiological markers.

So we see relationships between when we do these circadian behaviors, they impact our sleep-wake time. And I think where we go a little wrong is I think we believe that there is enormous variability talking about the general healthy population in terms of our internal preferences. And we know this from a lot of the literature and a lot of the research that's done on hunter-gatherers. They're all going to wake a little bit up after sunrise and they're going to fall asleep a little bit after sunset, right?

And indeed, when you put folks like us on a mountain with no electricity, we're all gonna fall asleep within a half an hour of each other. There's other evidence too, when we look at the timing of light exposure on mood and brain circuits, it's a beautiful paper, it was published in 2017. And basically, what it said is that when we're viewing light between 11 p.m. and 4 a.m., your dopamine system, motivation, reward, just doesn't work as well as it would have if you didn't view light between 11 p.m. and

4 a.m. And of course, if you're doing that, you know, once every now and again, not a big deal. But if you're chronically viewing light between 11 p.m. and 4 a.m., which is probably 70% of the world's population at this point, like a lot of folks are getting light to the eyes, which is confusing the control center of the brain, saying we're supposed to be awake, which is then telling all of the clocks in the body that's time to be awake at times when, again,

they're not programmed to be awake. They're not programmed to be firing, right? So again, this puts enormous stress on the system. So I think studies like that tell us, okay, there's something that we need to protect this timeframe. This is a time when we are not supposed to be active and awake. Yeah. What you said about, we're not as varied as we might think. I'm so happy to hear you say that. You know, night owl, morning lark. I know they talk about chronotypes. It just doesn't fit with what I've seen. I've had patients who swear to me that they're night owls. Swear to me.

I said, okay, look, this is the consequence at the moment if you being a night owl, you know, would you like to change that? A lot of them will say, okay, this is the consequence at the moment if you being an eye towel, you know, would you like to change that? A lot of them will say, okay, but is it possible? I said, okay, well, let's just try for a couple of weeks, you know, changing a few things. Light exposure in the evening being a huge one. Let's cut that out as much as we can. Let's get your dinner a bit earlier. Let's get you up early and get you outside, right?

It is amazing how many night towels suddenly say, oh, I'm doing really well as a morning log. Now, I can't say that that's for every single person, right? And I recognize that many sleep experts are saying that there are these chronotypes. But as you say, those studies where you go out camping or they go out to the mountains, when that happens and we're removed from artificial light, it all starts to sync up a bit better, doesn't it? It really does. And the evidence is just so darn clear to me. You know, this notion that we have these really, you know, varied chronotypes that span five hours. When I interpret the literature, that's just not, that's not what I see, right?

I see preferences. You know, and I think we've created this notion of chronotype out of convenience, you know, really, because it's just, let's focus off the hook. You know, it's, you know, I'm the night owl. I'm gonna stay up, but I'm gonna watch Netflix until 1 a.m. You know, we're really making choices, right? And we just have to own that choice, but we have to recognize that it is having a deleterious

effect on our health, well-being and our longevity, right? Mental, physical, emotional. What you said about dopamine was really interesting. You mentioned that if we are regularly up looking at lights between 11 PM and 4 AM, then our dopaminergic system doesn't work as well the following day. Now that has some quite profound implications. Your motivation, your ability, your drive, your willingness to do the things that are required of you are going to be affected by that. So you might think you have no focus, you can't resist temptation, you don't have passion. You may think that that's who you are, that's your personality, but maybe it ain't your

personality. Maybe it's a consequence of the fact that you were viewing light at midnight. We know that our circadian rhythm is not exactly 24 hours, right? It's slightly beyond that. And then we are setting it every day based on light and dark. So the fact that we can change and respond to jet lag and time zones means that we can change it and our environmental inputs ultimately are what dictate it, right? So I think it's empowering because it goes, okay, what choices can I make to harmonize my circadian rhythm

in the context of my life as much as I can? Yeah, I've seen in my own experience, you know, as a coach, I was, you know, very much a night owl, you know, like I was cutting film, like late into the night, I was sending emails, I was, you know, very much a night owl. You know, like I was cutting film, like late into the night, I was sending emails. I was doing all sorts of stuff during the night. And I've personally have been able to shift

my circadian rhythm to an optimal kind of zone. And I have seen, I can see now that I had just literally adapted to a lower level of functioning. Like I didn't even know what I was leaving on the table. You know, I thought I was being so productive and I was by all intents and purposes, very successful. When I look back on like my health, I was a mess. It has, it's completely transformed my life,

aligning my circadian rhythms. That is really empowering for people who think that the way that they feel right now is the way they have to stay. And it's simply not true. You can change anytime you want. Yes, for some people it's harder than others, but actually a lot of the time it's not as hard as we think.

We don't necessarily need a huge lifestyle overhaul. A few simple things done consistently really very quickly start to move the needle. But I imagine also there's been a feed forward cycle whereby it was hard initially, but then you start to feel the benefits. It's just a way of life now. Yeah. And then you want to continue that way. That's how I feel. I love living in good circadian harmony. I just feel great. You have concluded, along with the research, that a regular sleep-wait time is one of the

top-line behaviors we should all be striving for. I will go on a limb and say that I think it is the most important behavior. If we're talking about wanting to really optimize our health and longevity. And I try to keep my variability around 30 minutes. I think when we have a stable sleep-wake time and we're getting sufficient sleep matters, right, we need to spend enough time in bed, right, there's no question. And I think that sweet spot for folks is somewhere between seven and eight hours for like adults. And I will say that when folks start to stabilize

their sleep wake time, they end up with less light sleep, less awake sleep, right? Because their sleep becomes more efficient. And when people are trying to kind of incorporate a more stable sleep wake time, the most important thing is to wake up at the same time every day and view light. Even if it means potentially having a bit of a shorter sleep,

that same wake-up time is absolutely critical for setting your circadian rhythm, right? And dropping melatonin at the time that you need to, right, to fall asleep and stay asleep. When we talk about the coaching piece of circadian alignment, that's where you start. You wake up, if you know, all right, I want to wake up at seven,

literally as soon as you wake up, get yourself out of bed and get out into the morning sunlight, or the morning natural light. It doesn't have to be sunny out, but just you want to get out in a natural light. You want to look up at the sky for at least five, you know, to 10 minutes, and then go about your at the sky for at least five to 10 minutes and

then go about your day. That's going to help set your circadian rhythm. People spend 97% of their adult lives indoors. Yeah. So we're missing the number one input, which is light. Yeah, natural light. Okay. So this is super fascinating. Okay, so it can be challenging for people in different jobs and different points in their life, but if possible, you're saying try and have the same bedtime and the same wake time. If you're slightly off on your bedtime, try and keep the wake time consistent. If you do need to shift it a little bit day to day, try not to more than 30 minutes or

so. Is that kind of the essence of the sleep weight recommendations? And then we know that the bare minimum that folks should be spending outdoor is 67 minutes if we are interested in mental health. So just the natural light in general has such an impact on our skin health, on vitamin D, our mental health, our mood, our alertness. So important, right? That's what we know in the, that's kind of what's been defined in the literature as being

like the minimum effective dose for humans. Yeah. I mean, that's fascinating. And I think that makes complete sense. I mean, we've evolved outdoors. We've never spent this long inside. 67 minutes though, to some people will be like, wow. It's an eternity. I did not spend 67 minutes outside yesterday, but I'm acutely aware. I know today, unfortunately, it's a holiday and I'll be outside all the rest of the day.

I'm going to kind of make up for it. And I think that that, you know, it's not perfect science, but that's kind of in my head how I think about it. And I just try to, on average across a month, schedule my time so I can hit these minimum thresholds. And that's really how I'm operating. Yeah. Now I must deal with night shift workers. I really don't want people leaving this feeling worried and scared. Right. So, okay. You did a series of beautiful Instagram videos, which I would direct people to if they want to know your views on this, right?

One was if you're on a series of night shifts. So I don't know, when I was a junior doctor, we would do seven nights in a row, for example. Right, right. You had some advice on how to stay on a night pattern. It's all there in those Instagram posts. I wonder if you could share some of your top line recommendations there, please. Yes. And again, this is the caveat is you need to be able to do this. All these things I'm talking about as safely as possible, right? I think sleeping as close to the end of your shift is from what I've seen, what I've heard, and in the data that we have on frontline healthcare clinicians, that seems to be the best protocol to get in the most hours of sleep during the night and have the most restorative

sleep. People who delay their sleep end up with much shorter sleep and more fragmented sleep. Try to minimize light in the lead up to bed. So sunglasses, hats, again, as safely as you can, because that light to the eye, again, is really gonna wake up the system. And then you wanna try to sleep for seven hours minimum. So you wanna get a consolidated sleep.

And then when you wake up, work out, have a meal, be active, you know, catch up with the family before you go on to your shift. Yeah. Right? Yeah. Zooming out. It's this theme throughout this conversation that we have a circadian rhythm. It's important as much as we can. And some people are going to struggle for sure that we match those external behaviours to our internal

circadian rhythms. Actually, if you can learn to master this, you kind of become a master of your physiology because you understand how to manipulate it, right? Yeah. There's lots of subjective questions that we should be asking ourselves. What are my energy levels? Do I feel alert when I want to feel alert? Do I feel sleepy when I want to feel sleepy? Am I attending to things that I care about? Am I able to control and direct my thoughts? These are questions that all humans should be asking of themselves. The answer to those questions is a direct comment on likely how we're managing our physiology.

It gives us the foundation, I think, to live our values with joy and energy. I think that's kind of at a fundamental level what we're all after. Hope you enjoyed that Bite Size clip. Hope you have a wonderful weekend. I'll be back next week with my long-form conversational Wednesday and the latest episode of Bite Science next Friday.