Uncovering Secrets of a Long, Healthy Life Episode One

Want to live a longer, healthier life? Learn how to take control with wise choices, healthy habits.

The content shared in this podcast is for informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. While our doctors provide insights on healthy living, always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you have heard on this podcast.

Uncovering Secrets of a Long, Healthy Life Episode One
Featured Speaker:
Tim Arnold, M.D.

With 22 years in practice, Dr. Tim Arnold is a family physician at Riverwood Healthcare Center in Aitkin, Minnesota. Based at a primary care clinic in McGregor, he practices the full spectrum of family medicine for patients in all stages of life from pediatrics through child-bearing and senior years.

In addition to caring for patients, Dr. Arnold is the chief medical information officer, serving as the liaison between the medical staff and the information technology team.

Dr. Arnold describes his personal approach to medical care as: “Good health starts with nutrition, exercise and good choices. I take a team approach, collaborating with my patients.”

Earning his medical degree from the University of Minnesota Medical School in Minneapolis, Dr. Arnold completed a bachelor’s degree in biology from St. Johns’ University in central Minnesota. He completed a three-year residency at Duluth Family Practice at St. Luke’s and St. Mary’s hospitals in Duluth, Minnesota.

Dr. Arnold and his wife, Terri, have two children and enjoy outdoor activities, including camping, fishing, hunting, horseback riding and taking care of farm animals at home.

Transcription:
Uncovering Secrets of a Long, Healthy Life Episode One

 Dr. David Taylor (Host): Greetings, this is David Taylor with the On Call podcast from Riverwood Healthcare Center in Aiken, Minnesota. Today, my guest is Dr. Timothy Arnold. He is a Family Physician at the McGregor Clinic, which is part of the Riverwood Healthcare System, and Riverwood Healthcare is a multi specialty clinic in north central Minnesota, and we focus a lot on primary care, and that's where we're going to start with our podcast today. Good afternoon, Dr. Arnold.


Tim Arnold, MD: Thank you. Thanks for having me.


Host: Well, we're very happy to have you here. So I guess I'd like to start by just kind of introducing you and asking you a few questions. I introduced your name, but can you tell me a little bit about how you got into medicine, how you chose family medicine as your specialty, and some of your passions and interests in medicine?


Tim Arnold, MD: So it started early on in college. My first year of college, I was really interested in the sciences. Went to graduate in physics and decided I couldn't do the math. And really, really liked the biology side of it. And ended up in college becoming an EMT on campus and doing emergency medicine. And then worked for an ambulance service and decided, Hey, this is really interesting.


I should probably go into medicine. So, that's kind of brought me to medical school. And then, the reason I chose primary care was in medical school, I liked everything I did. There wasn't a thing I did that I didn't like to do. Every rotation, every specialty, oh, I think this is what I want to do.


And then, so in the end, kind of decided, well, family medicine, you get to do pretty much all of it if you want to. And so that was the place for me.


Host: And then once you got into family medicine, have you found some areas that you're really passionate about or that you like to focus on?


Tim Arnold, MD: Yeah, in terms of the medicine side of things, I think in the last 5 to 10 years, the area that I would love to spend most of my time in, if I could, would be this concept of longevity or wellness or health span.


Host: Can you tell us a little more about that? What do you mean by that?


Tim Arnold, MD: I think it's probably best for us to just step back a second and maybe try to define a couple of terms for the listeners just to help frame the conversation. We a lot of times in medicine talk about wellness or health, and then of course, on the opposite side of that coin is disease. And these are actually terms that are pretty hard to define, honestly. And so first, I think it probably would be easiest to define wellness or good health. And the way that I sort of look at it is, it's really not the absence of some sort of certain problem. If you think about it, maybe we were born without a hand that worked correctly or something.


It doesn't mean that you're not well just because you have a hand that doesn't work correctly. Or maybe, you had an accident many years ago and some part of you doesn't function correctly, but all the rest of it does. So I think this concept of health and wellness really has to take into consideration the environment that you live in, the needs that you have to be able to get through your day.


It has to take into account the balance. I think a lot of it in terms of balance, if you remember back to med school, Dave, we oftentimes learn that there was always a balance to every system. So for example, if your heart rate went too high, the body worked hard to slow it down. If your temperature got too high, it worked hard to bring it down, or if it got too low, it worked hard to bring it back up again. And that balance across all of our organ systems and all of our heart and our lungs and our skin and our eyes and our digestive tract, there's always a balance. And so I think of health span or healthy in the absence of disease to be in balance, to have all these systems working as they were kind of in-tuned or designed to do so.


But it doesn't mean that you can't have something that isn't perfect. I think maybe we kind of get that in our minds sometimes confused. It doesn't have to be perfect. It just has to be in balance. And then I think in the opposite side, if we think about what disease means, it's dis ease or not at ease or not at balance.


There's a part in your body or an organ system or a component or something that is not in balance any longer. So if we have lung disease, our lungs are working harder than they are designed to. They're not in balance. So that's the way I think of that. So then if we kind of contrast that to wellness, take that concept and march it out over time.


And that's how I think of longevity. So there's this other concept of health span versus lifespan. So lifespan is going to be how long do we live versus health span is how long do we live healthy. So how long do we live in balance? So that's the area that I've kind of been the most interested in the last five or 10 years and spending all my extra free time just thinking about longevity and health span and wellness.


Host: Well, I appreciate you breaking it down like that. I think it might be important for listeners to know that that's not really, I mean, maybe it's taught in med school now. I don't know, and maybe you do, but it's a very significant change from how you and I were taught back in med school.


 This is a little different, but would probably fit well with what you're describing. I remember hearing a physician that I was listening to a few years ago say that everything is bio psycho social, and we were really only taught the bio. But when you're describing balance and taking the whole situation of any individual's health into account, you really need to take all of those. It's not just the biological aspect.


So I think that's a really good way to frame things and a really good way to start to think of our health and a great difference that you pointed out between health span and lifespan.


Tim Arnold, MD: And it's not something that, as you had stated, that I don't think we were ever trained in med school to think about health span. I don't think the word was ever used. And honestly, I don't think that we necessarily use it with our patients enough. We oftentimes still think about really things in kind of just numeric numbers.


How long are you going to be here? We don't really think about in terms of how long you're going to be here well and healthy and do the things that you want to do and be the person you want to be. It's a much different way of thinking about health in general.


Host: Right. If you're going to live to 92, but 10 of those years are needing a wheelchair and assistance to do activities of daily living versus you live to 89, but you were independent doing the things you love to do, that's obviously a huge difference, yet one person technically lived longer than the other.


Tim Arnold, MD: Absolutely, and that's a much different way of thinking about it. And 25 years ago when we did our training, no one ever talked to us about any of that. It was just kind of absolute numbers. And so I like to spend my time now thinking about how do I get my patients to live really long, but to also do it where they're healthy along the way. They have this really high health span and not necessarily lifespan.


Host: So, is there anything else you'd like to comment on how you're framing this, any of the definitions, before I move into one of the next topics I'd like to talk about?


Tim Arnold, MD: I do think it's important to say to the listener, that when I think about it this way, I really think about this from a really long perspective. These are not decisions or ways of thinking that apply to one year or two years or five years or 10 years. We really have to think about this in terms of decades and multiple decades.


And that's a really hard thing to do. It's kind of like investing or insurance or some of those other things that we have to make decisions on in our life that really reach out over many, many decades. And the speed at which we live our lives now, we oftentimes don't think of decisions within that framework.


Host: The caveat there being it's never too late.


Tim Arnold, MD: Absolutely.


Host: Just because we're talking about decades doesn't mean it isn't something you can start now, even if you're, know, 90.


Well, I guess along that line, what is the one thing that you would tell our listeners that they could start doing now or could look at incorporating into their life that would help broadly improve their health now and potential health span, overall?


Tim Arnold, MD: That's a pretty simple answer. It's exercise. Don't need to say much more than that, but I can certainly get into the reasons why.


Host: So I would like to give a brief overview of the reasons why, and then I think I'd like to ask you, how would somebody who's listening, look at incorporating that into their life, both from a beginner standpoint, an intermediate standpoint, and maybe even an expert standpoint. If you are somebody who's just thinking about getting into exercise, somebody who's been exercising some, that's what I define as intermediate here, but has never maybe made it a routine part of their life.


And then I would call expert, quote unquote, somebody who may not be high level or may be high level, but is exercising as part of a routine part of their life. If maybe we could break it down in some advice you'd give those three groups. But before we get to that point, let's start with a little bit of the why.


Why is exercise the first answer and why is it the easy, quick, answer.


Tim Arnold, MD: First of all, data. So I get this answer based on data. This isn't just my opinion. There are some really amazing data sets out there. There's a couple with, uh, million patient years and then multi million patient years in the data set. So, what that means is, uh, a million patients over one year or, one patient over a million years or any sort of multiple of that.


But in other words, it's a large, large amount of data, and that data tells us that it is the number one most predictive piece of data that we have that tells us how long people are going to live. And this is an all cause mortality. So all the reasons why people die, if you can, drop it into a bucket and look at what are the reasons why our population dies and at what age do they die and what is the most predictive piece of data that we have.


And it is absolutely their cardiovascular fitness.


Host: Let me interrupt you just for a second, just for the listener, because I understand what you're saying, that concept of looking at a group of people, and then looking at all cause mortality, meaning, if you have two groups, and in this case, one exercises and one does not, and the exercise group has a reduction in all cause mortality, it's a pretty good indicator that the exercise; especially if the groups are big enough, there's not going to be a lot of confounding variables in that. So that's what is so important about looking at it that way.


Tim Arnold, MD: So it's much more predictive than whether or not you smoke or not. It's much more predictive than whether or not you've had previous cancer or not. It's much more predictive in whether or not you have kidneys that don't function correctly. Some really tremendous things that I think our listeners would understand, that generally we think of as smoking is pretty hard on your health and generally shortens your life. It's even more predictive than that, when you compare someone who is sedentary versus someone who is elite fitness. And that is at all age groups. That's all the way up to into your 90s. And the reason why that happens, we sort of understand, is it is, the best predictor of how well the body runs efficiently.


We go back to this concept of health being this balance. And so my heart, or my lungs, or my skin, or my muscles, or my intestinal tract, all of those things have a balance point and they all become more efficient when we work them. The more that we work those systems, the more that we get those systems to do a little bit harder work, the more efficient that they become.


It is the best sort of integrator of all of the measurements and all the ways that the body works, in a healthy way. It also gets right down to the cellular level. So I was just talking about heart or lungs or skin or bones or muscles. Actually, you can actually go all the way down to the individual cell and you can see how that individual cell works better, when it's given some exercise and the energy processing in that cell improves over time.


Host: You know, you talked about heart and muscle, but there's effects on the brain too, correct? Or other tissues?


Tim Arnold, MD: lt's almost impossible to find a tissue or an organ system in the body that isn't affected by exercise. And it really has to do with blood flow and it has to do with energy and how well we can use the energy in that system and how efficiently that particular cell or organ system works.


Literally everything, your brain is really important. So if we want to avoid dementia and Alzheimer's, the number one most predictive piece of data we have to avoid that, is exercise.


Host: I think that bears repeating because I think people understand that if you lift weights, you're going to gain strength and you you might have increased bone health and the cardiovascular effects of what people term cardio exercise, but I think maybe it's lost on some people that it can help with depression or prevent things like Alzheimer's. So I think that is worth saying again.


Tim Arnold, MD: So here's a great example. You bring up lifting weights and I'm not talking about going in and pumping iron like big muscular guys do, this could be a can of soup or it could be a five pound weight in your hand. So this is a really interesting piece of data that I really didn't understand until about two years ago.


So just take weightlifting, for example, and dementia. Let's put those two things together and say to ourselves, gosh, can they really be tied together? They are very much tied together. And in this way. I did not understand, but now I do understand that the first couple of months of lifting weights, you aren't actually gaining a whole lot of muscle mass.


You aren't actually building the actual muscle component itself. What you're actually doing during those first couple of months, when your ability to lift that weight goes up, is you're actually building new nervous connection from the brain to the muscle first. That's the first thing that happens. You're not actually building the size of the muscle.


 Those first couple of months, you're actually building more connection from my brain to that particular muscle that you're working on. And that connection, those additional connections to the brain cause the brain to work better and be more efficient because it has more neurons and more ability to do the work that it needs to do.


So when you lift weights that first couple of months, you're not actually building muscle, you're building your brain.


Host: It's all about the brain is what you're saying initially, and that is probably counterintuitive to some. But it's a good point.


Tim Arnold, MD: And that applies to a different maneuver. Let's say you're lifting weights with a different set of muscles that you haven't really moved before. You're going to build all kinds of nervous connection to that group of muscles that you've never used before. And all those additional connections support all the other connections in the brain. It builds on itself. You've got a much stronger organ in your brain now because of those additional connections. So, exercise is one of the best things overall sort of bar none. And the other part to this, you had said, let's talk about the beginner, the intermediate, and the advanced.


So let's start with the beginner. The beginner is the one who actually gets the biggest benefit. So when you look at the change in healthspan longevity, the biggest benefit, is from zero to something. There's a huge gap that then forms for that patient in terms of their lifespan and their longevity and their health, just to go from sitting on the couch to actually getting up and maybe pedaling a stationary bike, even just for five minutes.


You get a huge gain from a walk down to the end of the driveway and back that you've never done before, just isn't something you normally do. Now we're going to walk to the end of the driveway and back. Huge gains are had in that very first step. And it doesn't matter what age you are as well.


This occurs at age 90. It occurs at age 5. It occurs at all age spectrums. So, there is never a time when it's too late. And you can always get a big bang just from starting from right from the very beginning.


Dr. David Taylor (Host): That's very, very encouraging. Just hearing that out loud.


Tim Arnold, MD: So contrast that to the elite athlete. If they add a small change, a five minute change to their workout, they're probably not going to gain a whole lot. They're going to gain a little bit, but not much. Whereas if you go from zero, to something you get this huge gain. So I think the great message to our patients listening out there is that it doesn't matter how old you are. It doesn't matter where you're at in life. It doesn't matter what you do. If all it is, is a two minute, walk that you've never done before, start there. Huge gains. It will make a change long term. It will change the trajectory of your life.


Host: So, I know what I have told people in the past when they ask me, but what do you tell patients if they say, Dr. Arnold, I hear what you're saying about making these improvements and how impactful it's going to be, but what should I do? Should I try to run? Should I try to lift? What should I try to do? Where do I start?


Tim Arnold, MD: The first thing is just start. That's the hardest thing, to get out of bed and start. The second thing I try to break down, fitness into basically four categories. And if you notice, I won't at all talk about aerobics or plyo or some sort of specific fitness program. That's not sort of the way that I look at this.


I think of this in really basically four big groups. One is, long and slow cardiovascular. So, what I mean by that is, walking or slow bike ride or, something where you're going to get your heart rate up and you're going to keep it up for 45 minutes to an hour. We're looking for about 60 percent of your maximum.


The easiest way to sort of figure that out for most patients is if you can be breathing a little bit harder, such that you could actually talk on the phone with somebody. They would be a little annoyed with you. They knew that you were working out or that you're walking or exercising, but you could still have the conversation with them.


So if you can find that spot where you're breathing a little bit harder than normal, and you can hold that for an hour, that's a great first starting place. So, long and slow.


Host: Let me add just a little editorial there. Totally hear that and agree. Some people may know that as zone two. Some people may have heard what you're describing there is the rate of perceived exertion. So just in case people have read about this or seen it in other ways, what you're describing is a really easy.


Pretty reliable way without having to worry about heart rate straps or questioning whether your watch is picking up your heart rate or power meters on a bike or anything like that. You can actually measure that.


Tim Arnold, MD: So, long and slow. Get that breathing up to the point where you're annoying when you're talking to somebody, but you can still talk to somebody. That's a great kind of measurement. That's kind of bucket number one. Bucket number two, and this is not appropriate for everyone, and that is, to have some bouts where you really push the body hard.


So we technically call that something called VO2 max, but the way that I explain that to my patients is I want you to do a four minute kind of all out effort, whatever that can be, as long as you're safe and you're not going to injure yourself or hurt some sort of joint or something like that. So I want you to try to hold a really, really high effort for four minutes, whatever it might be, you need to kind of be at the end of your rope at four minutes, and then you give yourself a four minute rest.


Now, again, not everybody can do that off the start. That may not be appropriate for a large portion of our listeners, but that's something that we encourage not the beginner, but the intermediates or maybe the advanced person to start to think about in terms of exercise. And again, it doesn't matter what kind of exercise you do.


I just want you to hold that level of exercise to the point where you're pretty done at four minutes. You really don't have much left. Four minute rest, and then repeat that cycle again.


Host: This is probably the one where the standard disclaimer of check with your doctor before you embark on this, especially if you are getting into this, in middle age or older, it's probably out of prudence, a good idea to have a physical and talk with your provider about that.


Tim Arnold, MD: Correct. Yeah, but this concept of something we call VO2max, which I'll just, for the listeners, just try to explain it briefly. It's how much can you exercise in a certain period of time? How much energy can your body burn in a certain period of time? And we want that to be as high as we can.


And again, that has to do with this energy and this metabolism and some of the things that we've talked about before. So that's kind of bucket number two, not to get too into the technical weeds on that. So the first bucket again is long and slow. Second bucket is hard and short, as long as you're safe, talk with your doctor, all those kind of things.


The next bucket is going to be strength. So that gets to the muscle part of this. We know that our muscle mass drops off pretty precipitously at about 75 years of age. All things being equal for most people. We all lose muscle mass over time. And that muscle mass is really important for our body's ability to manage the energy that we take in in our food.


It's also really important to keep us off the floor, to get us off the floor, to keep us from tripping and breaking our hip, all kinds of things. So muscle mass is also very highly predictive of how long we're going to live and how healthy we're going to live during that timeframe.


 So we really encourage patients to work on muscle mass if they can. And we can certainly get further into the weeds on that one as well. But again, we talked about how that relates to your brain and how it relates to, all kinds of things. And then the last one is going to be balance, flexibility, that kind of thing. So our body's ability to have balance, our body's ability to have flexibility to keep our joints and our muscles and our ability to walk and ambulate and to get through our environment every day is really important. So balance flexibility is the last bucket in my mind.


Host: Well, I guess if you do yoga, if you do similar types of exercises, that may be right in your wheelhouse, but if you're typically a runner, if you're typically somebody who's in the gym lifting weights, that might not be something you think about as much as part of an exercise routine.


Tim Arnold, MD: And again, for the beginner, you can do this stuff in a chair. You can sit on your couch and do some of this work. And there are lots of researchers out there online to try to find those types of programs where you can start to work on flexibility and balance, even just sitting on your couch at home. So this doesn't take you going to a yoga class.


Host: I think that's a good primer for people to look at from why you would look at doing some of these exercises, why you would get into looking at strength, looking at, I know you didn't say cardiovascular work necessarily, but long, steady distance or long, slow distance, and then the short and hard exercise and balance as your four buckets.


Do you, have anything else you'd like to tell the beginner about that before we maybe see if you have some tips for the intermediate? And I can kind of be a little more specific with my question regarding intermediate.


Tim Arnold, MD: I think it really just comes down with just starting. Just start and worry about how well you do. Nobody's trying to win an event here. And there's, no prize here. Just do it. JUst start and don't worry about how you do. There's no fail or no right or wrong. Just get going.


Host: That's probably the best takeaway. Just start and it doesn't matter. It's just your own race. It's not anybody else's race you need to worry about. I've been reading a book to my kids, it's Bluey. If you're familiar with the kids series, Bluey, it's a dog and they have Australian accents. And the one book is all about running your own race. But I think about that in relation to what you're saying. It's something that everyone should consider. And not worry about, how they're doing related to other people. If you happen to be doing things in a class or worried about if you run a running race, it, really, for most people does not matter other than to satisfy that competitive side, which can have some mental benefits, but that's not the main goal.


Tim Arnold, MD: And don't let whatever limitation you have stop you. So if you have a knee that doesn't work well, or have arthritis or hip arthritis or something like that. Let's find something that you can do that doesn't require your hip to bear a bunch of weight. So, there does take some modification there, and everyone's going to be different, but don't let that stop you.


Host: I think if we do some future podcasts on this, or if we get a bunch of questions, we might also have the ability or the time to look into, Hey, I've got this condition. What would you recommend? And we can be more specific. I think as an introduction, this is a great way to start. So, in my mind, the way I was thinking about the question of what advice would you give an intermediate, I'm thinking about somebody who says, yeah, hey, I run three times a week.


I'm looking at expanding what I'm doing. Do you have some recommendations? Or vice versa. I'm, lifting weights and I'm really comfortable with where I am with my lifting program. But what else would you recommend I do, looking at my health span, looking at my health and taking that into account?


Do you have any specific advice that way?


Within the realm of exercise. But let's say I'm a runner and that's all I do, and I'm looking at you as, is there anything I could expand upon, should I expand my volume of running? Should I focus on some VO2 max training to see if I can overall improve my VO2 max, improve my running, or should I look to expand into other areas of exercise working on those other buckets?


Tim Arnold, MD: I do think it's really important for an intermediate or advanced person to step back and think about, what ruts are they in and do they have a wide variety of exercise components or regimens? I think it's really easy if you're a runner, just run every day and then you miss out on that other stuff.


So you really have to kind of take an audit of what it is that you do and just make sure that you do lots and lots of things because that's where the body becomes really flexible and really adaptable is when you ask it to do things that it hasn't done before. So you really have to stand back and do that audit.


If you're looking for a specific, what I typically encourage folks to do is, the hard and fast sort of this VO2 max, basically one to two days a week, the long and slow, this quote unquote zone two, another one to two to three days a week, and then balance strength and flexibility the last one to two, somewhere in that general vicinity.


Dr. David Taylor (Host): Yeah, that is kind of what I was looking for, kind of a little general framework, and I wasn't necessarily thinking you'd answer it that way, but I really like what you brought up about looking at the ruts that we get into, because one of the bits of advice I will typically give people is, do what you're going to do. If you don't enjoy an activity, you're not going to do it. I do not really enjoy yoga for the most part. And so as a result, I don't typically do it. Whereas I really enjoy bike riding or, I enjoy a lot of other activities and I will do them. So it's easy, but then that same thing happens.


I get into a rut and I think that's a really good point to look at. Try not to get into a rut. Try to look at those other buckets that you may not be focusing on and try to add them in. And I think you gave a good framework for that. All right. I think maybe as we wrap up, and I really wanted this to be an introductory conversation today with the idea that we'd be having some future conversations.


And if we get questions that come in, we can address some of those. As we wrap up today, are there any ways you would approach the expert, the person who is either a very committed, enthusiast athlete versus an actual elite athlete as your patient? Are there any approaches you would take? Any specific advice you would recommend?


Tim Arnold, MD: I would probably start to look at some more defined data on them. I would start to think about some very technical things like lactate threshold and VO2 max and some other things I would start to look at getting into. Some of those very, very specific, fine data elements, and that would get pretty technical, I think.


Host: Yeah, so those would also be pretty individualized.


Tim Arnold, MD: Correct. Yep. I would like to say, as we're wrapping this up, though, you had asked me in the beginning, you know, what's the one thing that you would advise patients to do to, to affect their health overall? And my answer was exercise. There is a really close second. And I want to mention that, and I kind of want to set up future discussions. Because there's a bunch of other categories, and I think of health span as really a triangle. At the very bottom, the bottom layer of that triangle is going to be exercise. If you kind of divide the triangle up into slices. Okay, at the very top, you got a tiny little slice because it's right at the peak.


So the very bottom of that triangle is going to be exercise, and then the very next slice is going to be sleep. And then the very next slice up, which occupies just a smaller amount of the overall triangle, is going to be nutrition. That's something that most of our society focuses a lot on. But if you notice, it's not the number one most important thing on my list.


Host: Right. Or number two.


Tim Arnold, MD: Or number two. Right, exactly. And then the up one step and even smaller slice of that triangle is going to be this concept of hormesis, which we can talk about at another podcast potentially, but it's really this concept of asking the body to do things it's not used to doing, or maybe the mind.


So becoming more flexible because we can adapt to other environments or other things that we're not used to doing. That's really what that concept is.


And at the very, very top, the tiniest little piece of that triangle is molecules. Which is really basically medications or other non nutritive supplements. So, whether those are vitamins or something else, and if you notice that occupies the tiniest smallest fraction of that triangle, when we think about the overall, how do we, have good long, longevity.


That's the point of the triangle that most of our society puts their money in and their time and their energy in is what vitamin can I take? What supplement can I take? What thing can I ingest that's going to help me be more healthy? And if you notice, it is the smallest, tiniest piece of the overall pie or triangle of how do we have a long, healthy life. So, we can leave that for another podcast.


Host: We can. We didn't even talk about this yet. You teased a bunch of topics for the future. It's great. Well, you know what, Dr. Arnold, thank you very much for this conversation. I know we could have actually probably talked for a couple hours about the details of these things, and maybe in the future we will, but I really appreciate you, summarizing various components of exercise, and also summarizing that framework for how to think about health versus disease and keeping things in balance. And, I appreciate you being on and look forward to future conversations.


Tim Arnold, MD: Thank you.