Dr. Marco Altini, PhD: How to use Biometric Data as the Backbone of Your Intuition

In this episode, I have the distinct pleasure of hosting Dr. Marco Altini, PhD, a luminary in the realm of digital health and wearable technology. An Italian researcher and entrepreneur, Dr. Altini's expertise spans across computer science and biomedical engineering. He's not just an academic; Marco has transformed his knowledge into actionable insights for athletes and health enthusiasts alike. As the co-founder of HRV4Training, he's played a pivotal role in leveraging heart rate variability analysis to optimize training and recovery, bridging the gap between science and real-world applications.

Our conversation dives deep into the advancements in wearable technology and their profound impact on health and fitness monitoring. We explore the innovative mobile app, HRV4Training, and how it empowers users to harness their heart rate variability data to enhance their fitness and overall well-being. Furthermore, we delve into Marco's research related to sleep monitoring and the broader implications of his scientific findings. His insights offer a fascinating perspective on the confluence of technology, physiology, and health.

So, whether you're an athlete, a health enthusiast, or simply someone curious about the future of digital health, this episode promises a wealth of knowledge. Join us as we decode the science behind wearable technology and its transformative potential. Listen in!

Key Points From This Episode:

Timing of stressors is crucial for health and performance [00:00:00]
Understanding stress and body response [00:05:13]
Balance stress and prioritize health [00:11:05]
Understanding stress and its effects [00:17:34]
Balance subjective perception and data [00:27:42]
Wearable device data has limitations [00:29:02]
Baseline physiological stress changes [00:37:58]
Transparency is key for accuracy [00:41:56]
HRV measures stress response [00:51:25]
HRV is a useful tool [00:52:05]
Prioritize sleep, exercise, and nutrition [00:59:37]
Modify stress response for improvement [01:09:21]
Timing of stressors is crucial [01:11:32]
Listen to your body's data [01:17:28]

Links Mentioned in Today’s Episode:

Click HERE to save on BiOptimizers Magnesium

HRV4Training

Oura Ring

Cubitt (10% OFF)

BioStrap

Marco Altini

Marco Altini (LinkedIn)

Marco Altini (Instagram)

Transcript

00:00 Marco Altini
When you apply the stressor, it matters a lot, maybe even more than the type of stressor you apply. Because if you go hard when your body is already stressed and not ready to assimilate that stimulus, then basically you're just not gonna gain anything from it. So you just do that work, your risk to end up into a negative chronic response, and that could be at work, a burnout, and could be in training, being overtrained, all sorts of negative things, just poor health and performance. But the timing really matters. So if we want to set the stage, I think for better health and performance, we should try to manipulate the stressors in a way that is more in agreement with our body's ability to assimilate the stressor and respond to it positively over time.

00:39 Andres Preschel
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04:46 Marco Altini
Thank you. Thank you for the kind words. I really appreciate the invite.

04:49 Andres Preschel
So we have a major topic to explore today, which is interoception. It's my favorite word in the dictionary. But before we get to interoception, before we get to using data as a backbone for all things performance and lifestyle and all that good stuff, why don't you tell us a little bit about why you do what you do? Why did you become an expert in such a specific niche topic?

05:10 Marco Altini
Yeah, good question. Well, I had no plan, I would say, to get into this or to develop this very niche knowledge in a way into the topic of hardware reliability and how to measure our stress response and everything from technology and the physiology of it and use this data. I have a background in computer science and in engineering. That was maybe 10-15 years ago that I was studying at university and I was maybe not particularly captured by many of the topics we were studying those days. until I had the opportunity to do a course in which we basically looked at data captured with sensors that we could place also on the body to capture, for example, the activity of the heart, the activity of the brain, and those sort of bio-signals, we could call them. Yeah, and that opened a whole world basically for me. And finally I found something that was really engaging and interesting in a way that many of the other things I was studying were not. So I started to get a bit more familiar with the topics and go a bit deeper into this whole area. Then I did a PhD in basically machine learning applied to data. captured from the body, so how can we monitor certain signals, again, for example, the activity of the heart and then capture or estimate our behavior, our cardiovascular fitness level or sort of things associated to health and performance biomarkers. started two companies on similar topics, I would say. So one, we developed a sensor to track the activity of the uterus during pregnancy. So you could see, for example, changes in uterine activity, how that would be associated to clinical outcomes, potentially to pregnancy complications and things like that. Another one, which is the one I was around right now, which is essentially for training. So we develop apps and tools to track our trade variability and interpret that data. While developing this, apps and tools and working in these companies. I developed also, I would say, I don't know, I need to understand better certain aspects linked to the physiology more and less to the technology, which is really my background. So then I went again back to university, I studied also human movement sciences, it's called here in the Netherlands, it will be in sports science basically. So a bit more the other side of the picture how this data is normally used or understood in practice and then yeah at this point I just try to Combine these things, the technology, the physiology, building practical tools and to communicate and help people making use of the data. I think that's the most important thing at this point. The technology is there. We have good knowledge about these topics and we need to make use of it to basically just be healthy and perform better.

08:31 Andres Preschel
And why do you think that this particular topic resonated so closely with you? Because you were studying all sorts of stuff and everything seemed maybe dull or boring or just it didn't spark that interest. What was it about this science that sparked the interest and the passion?

08:46 Marco Altini
It made me stress, so now I leave it, yeah.

08:50 Andres Preschel
Well, you said as an understatement that you start to get curious about this, you start to dig into it. I mean, it wasn't just a little bit of an interest, it was a PhD in multiple degrees. Yeah. So what was the converting factor?

09:06 Marco Altini
Yeah, I think at the very beginning, maybe just a fascination, but then as I got more into this idea of monitoring the body and seeing Maybe the self-experimentation part of it, right? So how I could see certain things in my body in relation to stressors, how you would capture that with the data, that ability to quantify certain responses and then to change your physiology, for example, via training and things like that. I think that really clicked somehow in a way that And I got bored since then trying to understand this better and build tools to help people making use of the data.

09:44 Andres Preschel
And what were some of the first insights that you got into your own physiology? And I'll tell you what, as a preface to that question, the reason why I'm here doing this with you is because I was in my physiology classes unlocking things and learning things about my body that I was like, It was like a selfish thing, right? You're like, wow, look at what my body can do. Look at how I can adjust certain things. And then it became selfless over time as I got to learn more and more about the science and the applied science. But what was it in your case? What were some of the things that you learned about your physiology that showed you that, in fact, everyone needs to know about this science?

10:17 Marco Altini
Yeah, for sure I would say one of the main sites for me was that de-stressor that had the largest impact on my body despite all the research on HRV and training and all the training that we might be doing. it was really more the work-related stress. So as a scientist or an engineer or an entrepreneur, work is my main stressor. I exercise a lot, but it basically almost doesn't matter for my response. It's really a lot about how I live, that psychological stressor, the work-related stressors. And seeing those things quite clearly in the data, for me it was, Yeah, well, first the wake-up call, so how can I balance things a bit differently and try to basically be healthier and live better. But at the same time, it was also so obvious that this data that we can capture is not limited to training, which is one of its main applications. And I get that, right? There's a number of reasons, let's say, why I think training is one of the main applications, starting from the fact that the user is typically highly engaged, to the fact that the data is easier to use. Because if you need to change something, let's say your body is a bit more stressed and you want to adjust things, you just adjust the training, that is very easy, while if you have bigger stressors because something is off at work, in your family or there is some health issue, these kind of things. You cannot just switch them on and off or change them around. So it's just harder in life to use these things and to stay engaged with them. But they are equally informative because stress is stress, right? Your body doesn't really care where it comes from. So eventually having the ability to capture this Yeah, there's different responses, I think, can be very powerful. And for me, in the context of the stress response to, let's say, negative chronic work-related stress was quite insightful.

12:29 Andres Preschel
Right. And it's like with work-related stress, you could argue that there's more confounding variables because training, like physical training, you can approach it systematically. And with the insights that we get from wearable devices, We can adjust in a systematic way, but the work environment is so unique to us. It's a unique to an environment to our team. You know, there's so many of these variables that influence it. But like you said, the data still supports that. In fact, you are stressed, so you should take action. You know, we we we need to take this and do something with it. So what were some of the things that you did with this data? What were some of the differences that you noticed once you started to apply what you know about, let's say, stress management?

13:11 Marco Altini
Yeah, for sure. So I think there's many different factors that at the same time always play a role. So first, just the awareness has an impact on, let's say, how we perceive things. Because one aspect to remember is always that it's not just stress, right? It's not having to do with a stressful task. Does not necessarily lead to a negative stress response, right? So that is why monitoring your physiology is interesting because if it was just a way to capture the input of the stressor, then you know, we would maybe not need it as much because we might know what is the stressor. But what it tells us is really how we respond. So the same stressors, sometimes we could respond positively and sometimes negatively. This is true for training as well as for other non-training related stressors. So there could be situations in which a task at work is We respond well to it, even if it is very stressful, maybe something that challenges us, but still we do well. But then in another situation, even the same stressor, maybe it's a different time of the year, maybe there are some other stressors in our life, and then our response to the same stressor differs. And that's why I think it can be insightful to look at the data and see how things are going personally, often it was more about the simple things, I would say. Really trying to borrow terminology from training to periodize or submit the way we work, right? So you cannot always be on and always be, you know, working 12, 14 hours per day and do that, you know, Monday to Sunday. It's trivial, but, you know, when I was just out of school, that's basically what I was doing, you know. It's that phase of your life where maybe you feel like there's a lot to learn and you also need somewhat to prove yourself and to achieve the goals you set for yourself and things like that. And that's also a road that leads you typically to burnout and situations that are not ideal. Looking at the data I think can give you some depth level of awareness and for me personally it was about trying to make some changes at that level. But this process at this point has lasted more than 10 years, right? So there's a lot in there. There's interpersonal relationships changing. There's finding the place where you want to live. training and your relationship with exercise as well, how that changes over the years, with basic habits, sleep, diet, things like that, things you learn and try to prioritize over time. I would say really the basics and how you handle those for me that was the most important thing and I think that's also what I try to stress the most with other people as well. You know, sometimes you have people that have maybe an HRV that is on the low side and maybe later we can talk a bit about what that could mean, if we can do anything about that and things like that, but often we still maybe try to avoid the elephant in the room. So maybe this person is trying to exercise and eat well and all of that, but maybe you're also the CEO of a company and your job is obviously very stressful. So how are you doing with that? Are you handling it? Are you always on your phone 24-7 every day of the year? Those kind of things, like the macro stressors, I think I mentioned. matter the most and sometimes we sort of try to ignore them, so to speak.

17:08 Andres Preschel
Right, and so they add up and they have a big impact on your physiology. So if you can mitigate the micro stressors and if you can use data as a means of identifying whether or not you're chronically stressed, well now you have more incentive and more agency over your physiology and your stress response. Now, before we continue, because I do want to jump into the topic of HRV and understanding some of this data and applying it in the right way. But before we get there, would you mind defining for our listeners Stress. What's your definition of stress? What's your definition of hormesis, which I'm sure we're going to get into, and good stress and bad stress? So let's say generally, how would you define stress? What's good stress? What's bad stress?

17:56 Marco Altini
I would say that stress is something that causes a disruption in the system. And again, that could lead to a number of outcomes. So, to look back to the second part and the good and the bad stress, what determines that is how we respond to that stressor. And a bit like we were saying before, that could be highly dependent on you, the context. Other stressors happening at that time is not necessarily something associated to this specific stressor. That's part of the challenge. That's a bit how I see stress. So, some agent internal or external, I would say at this point, to the body that causes a disruption in our typical, let's call it, state of balance. in our body and to which the body responds again in different ways depending on the current situation and that is let's say an acute effect The acute effect is something we tend to study very well because you apply a stressor and then you look at the response and something even in the lab we try to look at different ways. What is more fascinating I think to me and also very poorly understood in general is how these plays are all done in the long term when things become chronic and many more factors play a role and that's a bit of a maybe different conversation

19:32 Andres Preschel
Right. And then would you mind describing this? Let's say there's a stress dial. How do we know when the good stress becomes bad stress? And can you describe this effect from a data perspective? So objectively and then subjectively, how does this actually feel when we go from the good stress to the bad stress? It's a great question.

19:55 Marco Altini
I think here, let's say that in terms of the data, the way I can think about this is to look at the stress response through markers of stress. And markers of stress could be ways to capture basically One of two things, typically, as we face a stressor, the body responds in a way so that we can see that response typically either in changes in autonomic activity, and that would be through markers of autonomic activity, like resting heart rate or heart rate variability, or through hormonal changes, and there we might look at cortisol, for example. For practical reasons, we look at heart rate variability or HRV and heart rate a lot more because we can capture that very easily. At this point, anytime, anywhere, and we cannot do the same with our hormones, basically. It's just, the technology is just not there right now. Hopefully in the future, we will be able to have a clearer picture of that too. So we look at one side, which is the autonomic response to stresses. And I think here it's also important to highlight a bit the timing of things. When we look objectively at the stress response. So what I mean is that when we face a stressor, during the stressor, we have what we could call a negative response. For example, heart rate could be elevated and the HRV could be suppressed. After the stressor, we will basically transition back to normal, let's say our values before the stressor. Now, when we measure the response, we need to let some time pass. So, I think it's important to understand that. Any stressor acutely seems negative even if it is actually eventually leading to positive response. Simple example is exercise. We measure these parameters during exercise and of course they are all looking like it's a terrible situation basically for your health and physiology, your heart rate is elevated, your HBs are suppressed and so on. but then we know that chronically exercise is good for you. And indeed, if you do a session and then you measure after a couple of hours, you'd expect your physiology to be perfectly normal, or even in a state that is better, so to speak, so higher HME and lower heart rate. with respect to before doing this session. So it's important that even when we try to look at things subjectively, we look at the right time frame. And I'm stressing this because now there's more technology than I just mentioned. And I think we risk to get into a situation in which we make any physiological response something that is, I don't know, medicalized almost, right? Something that is negative or to be concerned of while many of these changes and conditions are perfectly normal and physiology needs to be measured in certain specific times that maybe later we can discuss so that you are actually looking at this response after the stressor and after your body could re-normalize. And you're not just looking at it acutely as it happens or a minute or two later and getting worried about it because that's really not the point. So when we look at stress objectively, we apply a stressor, we know that there is a stressor, and then we look at how the body responds after the fact, when sometimes it's passed. as a negative response would still lead to, for example, a suppression HRV for a long time while everything goes well. After that acute response, you are normalized and then you have a positive response. So this state, let's say of stability, when your HRV or your SMRK goes back to your normal, that would be for me a positive stress response. And that's how I would distinguish, let's say, positive and negative stressors in terms of the individual response after some time. Subjectively, I'd say it's maybe not really my area of expertise. Obviously, I work with this data and with those subjective reporting of stress. I think that's also obviously very individual, but to think about your questions of when does it become, you know, negative chronically in terms of the response. I think it's, if I think even about myself, just as a case study subjectively, how I perceive stress and how this relates to the data, they do not always align, right? So I think that's one of the, interesting aspects, but also the challenging ones. Because that's also how people sometimes get disillusioned with technology, because they expect little they see to match how they feel. That is not necessarily the case. There could be different things, could be different dynamics. Sometimes maybe we have some sort of buffering capacity for stress. I had an example, last week I was in a short business trip, actually to to Oulu to visit Ora in Zealand and then those two days, you know, you spend time flying in airports and then working and then you get there and you don't sleep much and bed is not your bed and then you wake up early to train and those sort of things and I felt very fatigued and stressed, right? But my data was perfectly normal, so that was maybe somewhat a surprise. I thought, okay, maybe I had a couple of good months with basically a very stable life here. Maybe I have some buffering capacity for some sessions, but then I come back here and everything goes back to normal and I think, okay, now it must be staying where it is or even getting better. And instead, I have sort of a delayed crash. So my data starts to show suppressions and then it stays suppressed for actually four or five days. And in this period, after the first two, three days, I was feeling actually perfectly normal, not aligned with the data, but then the fatigue popped up to me and then eventually, they were aligned and data was basically telling me what was going to happen before it happened. Because then I started really feeling the old thing and the fatigue and so on. So I think the dynamics of our subjective perception and what data capture are not necessarily something that need to be aligned. There could be situations in which one is more informative than the other. I think the goal For me, it's never to use data instead of your field or your subjective perception. It's to try to combine the use of these two things, right?

27:14 Andres Preschel
Very, very well said. So if you can, in a clear and concise way for the folks that don't have a very good relationship with their devices, how would you say, in simple terms, and not that this, you know, everything that you said is absolutely clear, makes sense, but how would you describe for the average person tuning in how to have the best relationship with their biometric wearable data? I've seen the folks, you know, the type A individuals become obsessed and then everything is about their data. And I've seen people that wear the aura every day and don't even charge it. So like, how do you find a good balance between like having wearable data and then feeling good about how you're applying this? Like what's the ideal circumstance? One important thing is

28:07 Marco Altini
Yes, we have, you know, you have bought our wearable and you are paying your subscription and you have invested in this. But still, take a step back. There's a lot in there. Try, I would say, not to… Try to look at a few things maybe at the time also and I can give actually some Because I've been thinking about this a lot more recently in the context of wearables, just some pointers on how, you know, what to look at with more curiosity, let's say, and what you might actually rely on more as something that is actually more informative about your body's response. And, you know, devices provide a lot of metrics and they provide all of them as if they were derived the same way. So for the user, you do not know, for example, that typically that heart rate or pulse rate is actually measured by the optical sensor that is present in the device. While, for example, oxygen saturation is estimated with mathematical models, and then sleep stages are estimated with even more complex mathematical models that have a much larger error typically. So, I think this is important because sometimes social people get this illusion because they see one thing that they clearly can recognize that is incorrect. And then they think, well, then everything in this device is incorrect. But that is not really how it works. So some things are reliable, some things are less reliable. Things that are measured, for example, your heart rate and your HRV  and your skin temperature, Those tend to be more accurate, at least at rest. So when you see if they tend to be good signals. So I would have a look at those more than at what is built on top of that, which would be, again, sleep-related metrics, fitness estimates, calories estimates, and things like that. So when you start to look at your physiology, I think you can start to see how your body responds to the different things you do. which could be informative in different ways in terms of change and stress management. So I would start there. I would try not to go really all in. An example I made recently with athletes is also, you know, we Let's say the companies that sell these devices also try to build a bit of this rhetoric that you need to capture all this data 24-7 and that is so insightful. But if we take a step back and think a bit as athletes, what is our main limiter most of the time? and thinking endurance athletes, but probably actually even strength athletes or something like that, use their muscles in some way. Typically muscle soreness will be our main unit. And there is no way any of these sensors can measure it. So I think this simple annotation should make us understand that. we have clear limitations in terms of what is captured. And we cannot rely entirely on these devices because some things, at this point, we can only perceive them ourselves, for example, how sore we are. So if we try to understand that there's good data in there in terms of the physiological response of the body, but it's only always part of the picture in the context of our health and performance. then maybe we can start having a good relationship with the tool, which is one where, okay, we check the data because we want to see, we did this and that, and we want to see what happened, you know, has our heart rate increased, and maybe situational situations are very obvious, we're getting sick, maybe our heart rate has increased, skin temperature has increased, HRV has reduced. All of these things can help us understand that maybe it's a good day to stay home, and then also to see when we are getting back to normal, recovery time, when it's time to get back into our normal routines. So there are some things that are quite obvious when we look at the data. can be insightful also beyond what we can perceive sometimes, so the data can show us things a bit earlier, or after the fact, it can show us objectively if we have actually gone back to what we were before or not. So these kind of things, but always recognize that also not everything is captured by this device, any device, and that's fine. So we should not rely entirely only on them. At the same time, we cannot, I think, dismiss them because there is useful data which is just being trapped based on our physiology changes. So I hope that more people can find that kind of balance in there.

33:10 Andres Preschel
Yeah. And when would you say that this wearable device data is, let's say, the most valuable? So when is it? Like, are there certain times of the day or certain circumstances when we can reference this data and it has the greatest return on our investment? You know, actually looking at it and making decisions with it. Under what circumstances would that lie? Yeah, great questions.

33:34 Marco Altini
I think that is probably the most important thing. Once we have a good relationship with the data, we still cannot trust the data all the time. It's also tricky because even the data that is measured, for example, heart rate or HRV, there are situations in which the measurement is more accurate, and this one aspect. But that is not all. So even if you have accurate data, there are moments in which the meaning and interpretation changes. So in certain situations, the data that you have captured is not only accurate, but also physiologically meaningful, and we'll talk about what that means. And in other moments, you still capture accurate data, but it just has basically no physiological meaning in the context of your response to stress. So when we look at variables, there is the best moment to capture the data is actually how they started, which is during sleep, because you are not moving. So the first thing is that the technology works very well, it's accurate, because there's optical sensors, they are really prone to issues when there is movement. I think we all know that if you exercise or move your wrist a lot and you have a wrist device or you know, your finger, if you have an anemia, things like that, you know that this finger gets messed up and it does not work. while you're sleeping, the rate is accurate. But then the second part, which is eventually the important one, is that during sleep, this is also more meaningful, physiologically speaking, because you are measuring at rest. So you get a snapshot of your resting physiology. That's typically hours after stressors. For example, if you were stressed during the day, you exercised during the day, you were traveling, you know, then you have your dinner, you have your evening, you go to bed and then you're at rest and hours have passed from the stresses and you capture your body's response so if everything goes fine and you are responding well to the stress, your physiology should show that things are pretty much where they were before so 24 hours before, the night before, you should have similar effects And alternative to this, if you do not have a wearable, but you still track your physiology with an app or, you know, again, we make one that you can use to track your physiology with a phone. Others can be linked to an external sensor, chest pump, things like that. You can take a snapshot of your physiology first thing in the morning. It is not different from doing things like measuring your body weight first thing in the morning, right? You do it in a context. in which you can do it more or less the same way every day and before you do things that impact the data. In case of weight, it could be before you eat or before you exercise. In case of HRV, which is, again, a marker of your autonomic nervous system response to stress. So basically measure also before you do anything else, because anything impacts your autonomic nervous system. So before you exercise, eat, or start thinking about those other things that could upset you, or read your social media, things like that. So you wake up, take your measurement, that is also resting physiology measurement, very similar to a night measurement that you could take as you sleep with a wearable. So in those contexts, the data represents your stress response. And those are, I think, both the ideal moments to capture the data. Because if you measure, for example, if I measure my HRVright now, I can also get an accurate measurement because I'm not worried. I'm just sitting here and talking to you. but then this measurement is not really representative of much because first of all I'm talking so this will also disrupt my breathing and impact the data in a way and there might be some underlying stress so to speak, you know, engagement in the conversation and things like that So this measurement doesn't really tell me much. And if I was to drink some water now, then my HRV would be elevated for some time if I was to measure it. And that also doesn't mean anything. It's just that we are looking at things in a moment in which they are not really representative of what we are interested in, which is the stress response. That's why I think the night or the morning routine are key if you want to assess how our, what I would call, baseline physiological stress changes over time in response to all the stressors that we face.

38:12 Andres Preschel
Right, and it's ironic because if you wanted to double down on the accuracy, then the way these devices work, they would be incentivizing a sedentary lifestyle. Yes, exactly.

38:25 Marco Altini
Never move so you can get a good reading.

38:28 Andres Preschel
My aura is telling me to just sit around all day. Exactly. Interesting. OK. And let me ask you this question. And obviously, this is, in your case, slightly controversial. Do you think that the average person with a wearable device using an app and a platform, do you think that they alone, by monitoring their data and getting insights from the app, that they have enough to actually incentivize the right lifestyle changes? Or should they work with a coach or a professional? Or, you know, is there some next step that they need to take that they should take to genuinely have a good relationship with their science?

39:11 Marco Altini
Yeah, I think it's a great question. So personally, the way I see it right now is that if you have the opportunity to work with someone, that is fantastic. So it's really a way to step up this whole process. And again, we can borrow this from athletics and, you know, performance and every athlete as coach, more or less. And, you know, there's a lot that goes on in there in terms of the objective data, the subjective data, or simply establishing a plan. I think this is also key. When we do things for ourselves, often we are maybe reactive, very reactive. So even if we use the data, even if we have all the understanding of the data and how it works, then we might see some low scores some days, and we make some changes, and then we just up very quickly to what we see in the data, but maybe without the big picture and long-term plan, which I think should be always the first step when we start using these devices. So your goal should not be optimizing this metric or that metric. It should be more, you know, your health or your performance, depending on what you care about. And then you use the metrics to make some changes so that you get there. But yeah, working with someone, I think it's very powerful. We can, of course, just use the data. If we understand the limitations, what is captured, what is not captured, how to use it. I think it is tricky there because sometimes the companies are not too transparent in terms of all these differences that we try to I lied earlier about, you know, even which parameters are actually accurate, which ones are not. Everything, you know, I saw a lot of claims about everything always being great, but some things are better than others, and then it's easy to get food. I've seen a lot of people doing those sort of micro-lifestyle changes and then looking, for example, at how this would impact their sleep stages. and that's something that it's very hard to do because the technology works okay with the stages but it's not that it really gives you an information that is accurate enough and reliable enough to be able to make meaningful changes and you know trust the outcomes that you see And this can become a problem if we don't understand the difference between looking at your heart rate that is measured and all these things that are estimated and have a degree of error because then maybe we implement changes that really do not have a meaningful impact on our body. And all of these things are, yeah, again, just difficult to to understand because they're not communicated to us properly. So that level of transparency sometimes is missing. So I think we need to try to first get to a stage where we are a bit more transparent. And this is also the same with the quality of the data, things you were saying before, it was great when you're not moving, otherwise that's also well, but almost no device out there gives you information about the quality of the data, right? So you see the data, and when the data is low quality, you do not know. You can only guess. For example, even if you exercise and you have a device that measures heart rate, then sometimes you know that the heart rate is wrong. For example, certain periods maybe it's very high or very low. You know, it doesn't match what you were doing. And you just say, OK, there, it's incorrect. But the device probably also knows, but it does not report, hey, here, probably the data was not correct. I think if we were just to get to a stage where we are a bit more transparent with these things, there would be a lot to gain for the user. Because otherwise, it's easy to get fooled. And it's never the user's fault here. It's just how the devices operate, how they show the data, how they are marketed. I think obviously there's a lot of powerful information and useful information, but at the same time, yeah, it can be challenging to make use of them individually or also with the coach because the coach are not guaranteed that this person actually knows all of these things or can understand all of these differences. But typically, I think it can be helpful at least in the context of having a plan using the data with that optics in mind. So let's use it to make some changes to the plan, not to be reactive all the time and just make changes all the time without having this view of the long-term plan and the smaller adjustments that I think that's where the wearable can play a better role at this stage.

44:25 Andres Preschel
And who do you think is the ideal practitioner or professional that can work with people to do this? Who can actually grasp this and look at the big picture of someone's life and the data and help them take the best steps towards optimization regardless of what that Well, whatever that means for the individual, whether you're an athlete or a CEO or just the average person, who's the ideal practitioner?

44:49 Marco Altini
Yeah, probably very context-specific, I would say. I think here, a background in psychology would be very welcome, right, because also how we respond ourselves to the data and to the things that we see. Behavioral change, so behavioral scientists also obviously would help. So a lot of different skills from the planning, you know, depending on if you're an athlete, that would be a course which has expertise in your specific area. So I think it's a really a mix of skills. depending on the individual and the goals that we want to achieve. But there is, yeah, I wouldn't say that there is one aspect that is more important than the others, because then you also have the technology aspects. And so these things that I'm talking about, if I hadn't actually been through this technology, I don't think I would know when you can trust ease of that, or what can be done, what cannot be done. when the physiological link, meaning, let's say, between stress and leisurely breaks. Because, you know, I've done these studies and looked at the literature, but otherwise I think sometimes we trivialize many of these relationships. So, yeah, I don't think it's an easier role, but I think it's something that maybe in the future can be more common and a lot of people make use of all the data that they are collecting.

46:08 Andres Preschel
So definitely not like your average health coach. It should be someone that has a background in psychology, maybe behavioral sciences, perhaps exercise physiology or a blend of all the above that can actually interpret this and understand not only what it means, but your relationship with it. As we've described, there's one of the most important circumstances and characteristics that this process has to have of developing the right relationship with your physiology and what you're studying. And let me ask you this. Yeah, for sure. Obviously, you know, the technology still needs to evolve. We still need to, in a way, evolve. But what do you see as the ideal circumstances with, you know, human beings and their biometric wearable devices? Like, let's say five to ten years from now, where do you hope that we are with this data in our process of optimizing our performance, our health, our lives?

47:04 Marco Altini
Let's put it this way. In the past 10 years, we got really good at measuring some of these things. Before, it was not easy at all. If you look at maybe 95% of the literature on hard-hit variability, It's studies in which someone was taken to the lab, you take measurements of their resting physiology, then they do an intervention of several weeks and then back to the lab and take another snapshot of your resting physiology. And for anyone that has measured their HRV, I mean, it's almost a ridiculous approach because there is so much day-to-day variability in the data, right? So you could even capture the exact opposite of what happened just because maybe that was a low day at the end of the study, even in a week in which maybe you had a very good week and still got suppression a day, maybe you just had a heavy dinner, maybe you were just very stressed to be in the lab to take this measurement. the ecological validity, right, so the real-life applicability basically of these measurements and studies I think was very low. Now we measure continuously your home, right, while you're living your life and with some tools you don't even think about it when you're measuring the night. And all of this data is teaching us a lot on the relationship between stress and how we perceive it and the environment and different stressors and our health and our performance. So I think that has been great and there's a lot of studies going on. we know basically nothing about still is how do we actually change things in a positive way for example what is the impact if i was to do this intervention what would happen? What do we expect in terms of our physiology? If my HRV has been reducing for a couple of months, is that a seasonal effect or can I do something in terms of my behavior to change that? And does it even matter? That is even a bigger question, right? So yes, HRV is associated with many different clinical outcomes in different ways, but we don't really know what happens if we do an intervention that tries to target a change in your physiology, if that also eventually targets a change in the outcome in terms of health. all of these things we don't really know and I think I'd be interested to see if we can learn more about these things. Even the simplest things, exercise protocols, breathing protocols, like can we change how we respond to stresses in a way that our data is more stable and so we have less of these suppressions that are in theory negative and then maybe we don't get into these states of chronic suppressions that might last months or years. So yeah I would hope you know in the next decade Now that we can measure things so easily and that a lot of people are using them, maybe we learn more about how we influence them with simple protocols that might help our health and performance, and also try to learn maybe later how the change in the metric leads to or associates with a change in the actual outcome, which is eventually what matters more than the metric itself.

50:39 Andres Preschel
It's wonderfully said and I'm looking forward to that future as much as you are. You know, there's one question. I mean, all of these questions are just kind of in the spur of the moment, right? But there is one question that I think I've had for you ever since I discovered your work, maybe five or six years ago. And I don't know how far you're going to take this, but what is your definition of HRV for, let's say, I don't know, call it a teenager. Like, why does a teenager even need to know what an HRV is? But the question is, you know, when the average person stops you and says, hey, Marco, you know, what do you, what do you do, man? How would you describe this and how do you make it valuable for that, for any individual? What is HRV?

51:24 Marco Altini
Why does it matter? The way I think about HRV is as a proxy of our stress response. So it's, for us, the simplest, most practical way to capture how we respond to stress. And eventually, we all face stressors. So no matter what we do, it could be school, it could be training, it could be, you know, anything in our life. we deal with stress a lot, and that impacts our health, first of all, and then if we care about, you know, our performance in certain contexts, that will also be impacted. So by getting an idea of how we respond to stressors looking at HRV , becoming first a bit more aware of certain stressors and their impact on our body, then maybe we can start making some changes here and there, and then keep our health and performance where we want it to be. So that's a bit how I would say I think about it in simple terms, but I would say that eventually that's what it is when we do things the way we discussed earlier. So we look at it at the right time and the right context. that longitudinally over time and look at relative changes with respect to your own data and not absolute values, for example, and things like that. That's what it is in a certain context and how it can be used.

52:59 Andres Preschel
Is high HRV something that anybody can realistically achieve? I know that it's, I would mean, and please correct me if I'm wrong, but it's like one of, if not the most subjective, like Biometric a variable, right? It's like totally subjective. But is it something that everybody can you know improve? Or are there maybe some is there any reason why? You know even applying everything that we know about HRV that someone's a to remind I get up very high How subjective is it really and how much agency do we have over that?

53:37 Marco Altini
that value I think that we have agency but it is limited so I think it's very important to understand this because Shrone The angle I often look things at, let's say I talk to athletes or top performers or people that really try to check all the boxes, right? You know, sleep, diet, exercise, and those sort of things. I always think, okay, your absolute value almost does not matter. You look at how things change in relative terms, so when you have a suppression, you know there is more stress, and you look at things that way and try to make adjustments here and there to keep things stable. Now, this does not mean that you cannot change the absolute value. And there are situations in which, for sure, you can change it even by a lot. And I'm thinking, if we think about just the health of, you know, the current state of, let's say, the Western world, right? So, obesity, diabetes, all sorts of issues. Obviously, most people, if we measure their resting physiology, and we put them through behavioral and lifestyle changes, the arresting physiology will change dramatically. So things can change. But I think we do ourselves a disservice if we start looking at this metric and we think that we want to increase it because there could be, well, there is a strong genetic component. That means that more or less our HRV is around a certain value. And then if we are already healthy, it might be that it never goes higher than where it is. And it is useful in this context of capturing stress responses and making adjustments. And you might get to better health and better performance, but not necessarily better HRV. So I think it's important that we use the tool as a tool and not as the, you know, the metric to necessarily optimize because that might not be realistic. So that's why I don't like to say that, I mean, we do have agencies, again, we can change it, but I like to put some constraints on that and also to shift, typically, the conversation around, let's look at relative changes and let's use the data that way. Because it might be that in absolute numbers, it just will not change. We don't understand these things very well. Some people have very low HRV, so to speak, with respect to the population. If you look at the distribution of the population, some people will be on the lower end and they are LCM, they perform well, and they do all the right things. And I don't think we have an understanding of why that is the case. But clearly, at that point, there's some genetic component there that does not make it so easy to implement changes. That's why I think we should look at relative changes, always also within the context of what we discussed earlier of trying to have a relationship with the tool, with the metrics, use them effectively for what they can do. then if we make sometimes some lifestyle changes and things like that or if we have a lot of room for improvement then for sure we can also change our absolute HRV so to speak but that is yeah a bit let's say the framework in which I try to work in does that make sense to you?

57:19 Andres Preschel
Yeah, yeah, absolutely. So and I think that the main thing here for folks tuning in is like using HRV as a proxy, but not as the thing that you're trying to optimize, like try to optimize your behavior, try to optimize your lifestyle, and then look at how this may reflect on your HRV. But I see a lot of people, a lot of my clients included, you know, high performers in all categories who go, hey, I just need to get my HRV up, like I want to get it up like 20% or 20 points. And I'm just like, Let's improve the quality of life. And if it reflects, great, but I want you to feel the difference. But yeah, it absolutely makes sense.

57:53 Marco Altini
Sorry to interrupt. I will just add one thing because I think that also puts things in perspective with HRV and long-term changes. We don't understand all of this very well, but there are also seasonal changes. So that's also something to remember. So if you start working with a client and it's September and maybe you're getting towards winter, it's unlikely that you will increase their HRV because HRV tends to be a bit lower. in winter. So you're not a bad physio, a bad coach. It's just that, you know, there are also other changes there. And we need to remember those kinds of things. And that's also one of the reasons why sometimes, you know, we should just not think in those terms because it's not how physiology works, you know.

58:41 Andres Preschel
Some of the toughest conversations I have to have is in describing that although these are clinical grade wearable devices, it's not clinically perfect data that we're seeing because there's just so many confounding variables and just increasing a number for the sake of increasing a number isn't enough to actually change your life and your performance. I know that we're running short on time and I know that this next topic we can have several podcasts on. This is probably going to be the funnest part of the show for most people. But what would you say are like the highest ROI active to passive investments that just about anyone can make to objectively improve their quality of life in a way that the metrics can reflect? Everything from let's say if you wanted to start with like, I don't know, breath work as being the most accessible, you know, or you name it. But if you can give us a range from the active to the passive.

59:37 Marco Altini
Yes, I would say really to start with the very basics of are you eating well? Are you sleeping well? And are you active? And active really means moving possibly as frequently as possible, not just those 45 minutes of exercise that we are doing, but moving as much as possible and then staying active and then again prioritizing your sleep and trying to eat a healthy diet. I think these have evidence behind that interventions aiming at looking at these aspects also showed positive changes in, you know, reduced resting heart rate and increase in HRV. Those kind of things tend to show up when you address this. You mentioned breathwork. That's something that I think is very interesting because also tightly coupled with HRVin a way, right? So when you take deep breaths, you acutely increase your HRV . So there's that sort of stimulus. We could even call it in terms of the parasympathetic system. So the evidence there says that as you do the practice, there is a meaningful increase in HRV, it is acutely as you do it. So after the fact, it does not necessarily stay there. I think this is one of the also areas that interests me in terms of what we will learn in the future, right? So if you keep up the practice and do it according to best practices and protocols that typically involve quite some dedication, two blocks of 20 minutes per day for biofeedback typically, 10, 12 weeks at least to start with. And then if you see changes in your baseline physiology, I think that would be particularly interesting. There is mixed evidence. Some people have that response, others not. So I think those kind of things, all these practices. Can I jump in for a second? Yeah, go ahead. Yeah, please.

01:01:49 Andres Preschel
Yeah, so with respect to the breathwork, something that I find fascinating is how, you know, it's, again, like you said, it's very accessible. Like right now I can, as I'm speaking, my HRV is lowering. As you are listening, you're nasal breathing, you're using maybe the diaphragm, all of a sudden your HRV is higher, right? So it's very accessible. But over time, let's say that you are more conscious of just nasal breathing or like mouth taping while you sleep. In the beginning, it feels uncomfortable, but there are these changes in your physiology and anatomy. That start to evolve. So for example The nasal breathing some people that aren't used to nasal breathing. They get more of this air hunger So they feel like they need to mouth breathe But what's happening is as they continue to breathe through their nose they build up let's say their tolerance to higher levels of co2 Which is acidic gives you the urge to breathe and as you improve your co2 tolerance It becomes easier to nasal breathe as you nasal breathe you get more of this vasodilation in the sinuses, you know So there's all these different Changes in your anatomy and physiology and I would say yeah, like if you can pair this with biofeedback Oh my gosh, like now you have everything you need to really truly evolve the way that you breathe and then boom You have higher HRV and better control over your autonomic nervous system so to me that's fascinating because it can be used from everything from an active intervention all the way to a very very passive intervention and I can, I can, I can have a profound influence on your performance in a podcast to a Olympic, you know, time trial, um, and everything in between. Uh, so just wanted to, you know, share, share my perspective. Yeah.

01:03:22 Marco Altini
You make a good point there, especially on how the practice might lead to other changes. Right. Even I think even in our mind, right. So if I practice meditation, um, I do not necessarily expect a change in my HRV, but it changes the way I deal with stress then all the time, or at least I try to get there, to be less reactive, to respond differently when I face stressors or things that might annoy me. Sometimes just the act of doing it or remembering that I do that, you enter in that sort of character and you're like, okay, If I am this person that does this, I cannot be this person that gets all furious about trivial things. So I think so many things play a role eventually.

01:04:21 Andres Preschel
Interestingly, we've talked about this sort of stress dial and how we can add in these hormetic stressors. And if we can notice and monitor our physiology while we're engaged with them, we have more agency over our response. And what I've noticed personally is that there's three things that I've noticed, and I just want to get your take in perspective. Maybe you can help me elaborate for the audience and help them gain some value here. But the three things that I find that improve my HRV the most are when I'm consistently freediving and spearfishing and I have to be very aware of how I'm responding and how it influences my performance. when I'm exposing myself to the cold often, so cryotherapy, cold showers, and when I'm fasting consistently. And would you mind describing to the listeners scientifically why this actually has an impact on my HRV in the long term and how I can improve my performance outside of these activities?

01:05:17 Marco Altini
It's important also, I think, to highlight that this also might be individual. For example, I'm thinking about the fasting. So I was also reading more literature about this just recently. Well, there's obviously many different forms of fasting. There's even fasting that does not involve caloric restriction. There is fasting that involves caloric restriction. That will also have an impact. Let's say that In part of the literature, we see a reduction in resting heart rate and increase in HRV when there is some form of caloric restriction involved. Myself, I was experiencing this if I restrict calories a bit to lose some weight in the context of endurance and performance and for a race and things like that. Typically, they have quite an immediate acute response with heart rate that goes really low and nature really goes higher. It's not the same for everyone. Some people, maybe their body really feels that there is some sort of negative stressor and they go the other way around. So I think that's also why it's interesting to look at the data because you might be different from another person. And to make this even more interesting, I think, is that if we think about the example with exercise that acutely is negative but chronically is good, then even if you have a suppression in initial V, it does not necessarily mean that that is bad actually for us. It could be that if we do that for long enough, maybe we have a positive chronic response. So I think it's important to, this is not to say that the suppression in HRV will be good eventually, but it's just to say that it's not obvious and we don't know all of this well. So sometimes, yeah, we need to figure out sometimes with experimentations and things like that. Similar things related to cold exposure and cryotherapy. The opposite often would happen if you maybe do hot baths and you are exposed to hot temperature and things like that. would really raise your heart rate and you know your blood vessels dilate and you know your blood pressure reduces, your heart rate increases and you have all this sort of big stress response but that is also known to be quite good for your cardiovascular health if you do that long-term. So these relationships are complex. We could have certain acute effect, the same or the opposite chronic effect and based on these different stressors. What was the first one that you had mentioned? The first one was when you were spearfishing, I think, and diving. I wonder if that's because you are somewhat in the zone and that's something that you really, you know, you train for, you practice and then you execute and it's something that maybe puts your body in that state of, let's say, a positive response.

01:08:32 Andres Preschel
I certainly do achieve a flow state, but it's an environment where I see the influence of my stress and my performance to an extreme. And I think it inspires me to be or to build intuition with other circumstances, situations where there absolutely is. I mean, in every situation, right, there is a link between your stress response and your performance. But it's like that's like the extreme that shows me just how deep that link is. I think a lot of people would describe spearfishing as, I think it's very accessible. I think some people will say, oh, it's inaccessible to me. But the point that you just made is, in fact, we should try to find these subjective areas, experiences, and stressors that can help us modify our stress response to improve our quality of life in the long run, in the big picture. Uh, and, and, you know, which brings me to my last question, because I know that we're absolutely short on time. Um, and that is, you know, when you measure age, you know, being in your field, measuring and being so intimately involved in, in the biometrics that measure our stress response. What would you say some of the low hanging fruit to make sure that we can double down as much as possible on the hormetic stressor that is going to make us stronger, faster, fitter over time? Like how can we set the stage for physiology to gain as much from the positive stress that we add in?

01:09:59 Marco Altini
So one insight that monitoring gives us is about, again, how we respond, but then, in turn, it allows us to play with the timing of the structure. We talked before about, you know, coaching and having a plan. Normally, when we have a plan, that's a good starting point, but, you know, we all know the plan changes all the time. And the idea of the data and the feedback is that we can apply stresses when the body is ready to assimilate them in a way that will lead to better health and performance. And this has actually been shown in a few studies in exercise where looking at HRV, you would split two groups of people trained for the same event into a group that would follow the plan And the group that when their HRV is suppressed, for example, they would skip the high-intensity stimulus. So this group eventually trains less or less hard or does less high-intensity workouts, which is actually the stimulus that gives you the most improvement typically. But they end up performing either equally or better. This has been done. a number of studies, runners and cyclists, so there's a few of those. And that tells you that when you apply the stressor, matters a lot, maybe even more than the type of stressor you apply. Because if you go hard when your body is already stressed and not ready to assimilate that stimulus, then basically you're just not gonna gain anything from it. So you just do that work, your risk may be to end up into a negative chronic response and maybe that could be at work, a burnout, it could be in training, being over-trained, all sorts of negative things, just poor health and performance. But the timing really matters. So if you want to set the stage, I think for better health and performance, we should try to manipulate the stressors in a way that is more in agreement with our body's ability to assimilate the stressor and respond to it positively over time.

01:12:25 Andres Preschel
So Marco, what you're telling me is a great way to summarize what you do is you're an expert in smarter, not harder.

01:12:34 Marco Altini
Oh, man, that's it.

01:12:41 Andres Preschel
That's it. That's very well said. And that's actually a, that's absolutely perfect. Right. And it practically, Would you say that this is like as simple as waking up in the morning, looking at what your metrics are, you know, uh, saying, let's say your recovery score, right. Or your sleep score. And from there making the decision about how hard or how long, or if you're going to train or not, you know, is this what it kind of, what this effect looks like on a day-to-day basis and are available to us right now? Are they proficient in, uh, incentivizing that based on these scores?

01:13:17 Marco Altini
Yeah, so I would make, just to make it a bit more complex, I would make another distinction between your actual physiology and this course that you find in this tool. So I would say try to look at the actual physiology. Try to look at your resting heart rate, your HRV. Look at if those numbers have changed negatively. You have different ways to behave there. You can be very reactive. There is a suppression. You make a change. You can be less reactive. This is where the research is going now. you give it two, three days of suppression, and you're like, okay, now there's clearly a signal there, so let's just make the change now. So that could be a way to do it. The way why I say look at the physiology and not necessarily the readiness recovery scores, sleep scores, and things like that, is that The scores mix your physiology and your behavior. So sometimes you might have a low score because your behavior was different. You slept less, you exercised more, those things. But what you want to really see is how your body responded. It's not what the algorithm thinks you should be because of your behavior. For example, you slept a bit less, the algorithm thinks, hey, sleeping less means that you're tired, so that you should have a low recovery score or low readiness score. But then, what is your physiology actually saying? Because maybe that lower sleep or higher exercise did not impact your physiology negatively. And if you are maybe doing something specifically like training more on purpose because you want to lead to a certain response, then you really want to see, hey, how am I handling this higher intensity or volume training block. Is my physiology normal? Great. Is it suppressed? Not so good. But if you look at this course, they mix the two things, the behavior and the response, in a way that you really don't know what is happening there. That's why I would not use those. Even though that's the first thing you see, I would not use those for the decision making. There can be something useful in there as well, of course, especially if you don't have a plan, then maybe they try to, you know, combine a bit of everything and give you something that, again, is a bit of a reactive approach, but still is not to dismiss them entirely, but still it's a mathematical model with certain expectations depending on what's the input, and the input is not just physiology, it's also BA. So, if you look at the physiology, there's incarcerated HRV . look at those data, and then if you see a change and you feel good, maybe give it two days, give it three days, and then start implementing a change to make sure things go back to normal quickly. In the studies, we always wait, let's say for a couple of days, what we call a baseline change, so let's say a weekly change instead of a daily change, But that's because in a study, you know, these protocols that are the same for every person and, you know, replicate the study elsewhere, but in real life, things are a bit different, right? So sometimes you have an acute suppression one day and you also feel terrible. It's also doesn't make any sense to wait for three days before you make a change, right? So if you're getting sick and there is a huge red flag, you implement the change right away. That's why we always need to work with the subjective and the objective together to decide the best course of action, I think, in real life. But my advice would be, if you see changes in your resting physiology, resting heart rate, resting HRV, that stick for two, three days, even if you feel okay, that's maybe a moment to try to pause and try to assess what could be going wrong, what stressors have you faced, and can you maybe make some changes in the stressors you are going to face that day or in the following days, that could be reducing stressors like reducing training intensity, but it could also be giving priority to positive things that we discussed earlier, right? So maybe you just try to sleep a bit more, do some breathing exercises and things like that and leave the training untouched. So you have, I think, freedom to play with different things and see how that works and then learn over time.

01:17:27 Andres Preschel
Right. And I think this really speaks to the folks that, you know, are like that grind set mindset. It's like the folks that, you know, they have to show up every single day, go as hard as possible, you know, screw the data, like mental, you know, it's all a mental. Those people are going to burn out or they're going to have a shorter lifespan or they're going to get sick. And then that'll prevent you from going as hard as you really want to go in the long term, which is what actually matters. And, you know, I anecdotally, because, you know, you've shared half of the research. Anecdotally, I've seen my best physical performance, like when I was road cycling, I would take this very seriously. I would only cycle the days that I had high HRV, and it's how I was able to level up as a cyclist faster than anybody else around me, because they were going every single day. It's all, it's a lifestyle, and I'm all for the lifestyle, but I was going on the days where my body was prepared to do it, and I was recovering better, so I was able to accelerate my performance. And I think anybody that wants to accelerate their performance should look at their data. Yeah, absolutely. Well, look, I know we have to conclude this show. Is there anything else that you want to leave with our audience? Maybe where they can find you, where they can stay in touch, if they want to ask you any questions, any incoming works or books or anything that you want to make sure we mention here on the show?

01:18:42 Marco Altini
Yeah, so people can find me on Twitter at Letheni underscore Marco. That's last name underscore first name. I write some stuff these days. So when I try to cover a lot of these aspects, so that's also probably one of the best ways to stay up to date with the work and also engage people always to comment and ask questions. And I try to reply to everyone.

01:19:06 Andres Preschel
Cool. Well, Marco, it's been an absolute honor and a pleasure. Thank you so much. And I hope to have you back on the show very soon. Thank you so much. So that's all for today's show. Thank you so much for tuning in today. For all of the show notes, including clickable links to anything and everything that we discussed today, everything from discount codes to videos, to research articles, books, tips, tricks, techniques, and of course, to learn more about the guest on today's episode, all you have to do is head to my website, AndresPreschel.com. That's A-N-D-R-E-S-P-R-E-S-C-H-E-L.com. and go to podcasts. You can also leave your feedback, questions, and suggestions for future episodes, future guests, so on and so forth. Thanks again for tuning in and I'll see you on the next one. Have a lovely rest of your day.