Exercise Immunology with Dr. Glen Davison PhD⎮KoopCast Episode 25

what's going on trail runners welcome to another episode of the KoopCast i'm really psyched that you are here joining me today i know a lot of you out there are extremely concerned about your health your well-being and your immune function during this time that the covid19 pandemic is running rampant around the world that's a totally natural response however your immune system response is something that is incredibly complicated and not a lot of people understand a lot of immunologists and a lot of exercise immunologists have kind of started to make the rounds around the lay publications and in the popular media and what i did today is i wanted to bring on an exercise immunologist to really kind of set the basis for what our immune system does and what we can do to better support it so i brought on the podcast dr glenn davidson who's a reader and research director or the director of research in the school of sport and exercise science at the university of kent where he uh currently teaches there he also coordinates the endurance research group uh which means he has this kind of a specific role in working with and understanding endurance athletes he achieved his PhD in nutrition and exercise immunology from londonboro university in 2006 and he's also a basis

accredited sports and exercise scientist as well as a chartered uh scientist he comes to us with just a wealth of experience in immunology in exercise science and specifically in exercise immunology as well and although this area of immunology is heightened during the current pandemic that we're all experiencing really from a coaching perspective and i can speak on the last 20 years that i've been working with athletes it's something that we have to be keenly aware of at all times every year there's a flu season and every year there's a season where athletes just simply get sick and we always want to take safeguards against athletes becoming ill or infected with some sort of uh with some sort of virus because it's just simply a robber of training availability and training availability the number of days and the number of hours that you can actually train is such an incredibly important part of success on the whole as any individual athlete and so what i try to do with this conversation is i wanted to make it more evergreen it would be very easily it would be very easy to get caught in the weeds of how covid19 works how this current coronavirus is affecting uh athletes what we need to watch out for do we need to wear you know ppe when we're out and running and things like that and um i really felt that that type of conversation would just be a little bit too here and now and

also since we're very early in this novel and learning about this novel coronavirus we would just be guessing a lot and i wanted to get down to the heart of the matter and deliver a lot of practical relevant and evergreen information that athletes can not only take away for the next two weeks but take away for forever in order to protect themselves uh from illness and from infections and so we cover a number of different topics including just to how a general framework of how the immune system works how these different components of the innate and the adaptive immune system works um how much exercise is safe and how hard exercise can we actually go and do we actually know the answers to those questions amongst uh a big group of people we also go into how some of the research is being interpreted and maybe uh perhaps being misinterpreted uh when we look at some of the things that are actually coming out as it has to do with supplements and uh in immune response i found this conversation incredibly enlightening i learned a lot of things that i did not know previously i really appreciate dr davison for uh coming on and spending some of his incredibly valuable time uh which is which is becoming far less and less common for these exercise immunologists right now and so i hope that the listeners out there i hope you all get some practical relevant and some immediately actionable information that you can take away uh that you can do some things to

really protect yourself here and now and i also hope that you get some information that really helps put you at ease in terms of how you could actually be impacted by the virus that's going around and also for any sort of future illnesses or virus uh viruses that go around for years to come so kick back turn your ears up and hope you have a good time with my conversation here with dr glenn davison talking about exercise immunology and everything about viruses what's like the lockdown situation around where where you live specifically um it's i mean it's it's pretty national sort of pretty standard standard guidelines at the moment and it's just um don't don't basically go out unless you really have to but if you're able to work at home you you should work at home um like all public gatherings uh shut down so pubs and cafes and public parks and everything are just closed um and you are allowed to go out once a day for exercise um but you have they basically say you shouldn't like you know jump in the car and drive several hours to to get somewhere to exercise it should be you know basically go from your door or you know if you do have to drive then it should be

with like the length of time it takes you to get there should be less considerably than than the amount of exercise you're going to right you're going to do so um yeah and they're just trying to learn well they are asking that we maintain this social distancing um sort of thing so stay two meters gap between you and strangers it's like um which is it's funny when you're out for a run and you're you're kind of going down the pavement and you see somebody coming the other way and you're kind of like okay who's gonna who's gonna jump out into the middle of the road so that we can pass kind of thing but yeah yeah yeah i i mean i live here in colorado springs colorado we have a great trail network just kind of in my backyard and it's pretty built so this the standards that they use to build trails here what they call equine standards so it's a 36 inch trail surface three you know three three feet pretty close to two meters and so there's just enough room if one runner's on one edge of the trail and the other runners on the other edge of the trail that you can maintain that you know that two meters three feet of of of physical distance but you end up running kind of like up on a berm or just kind of like brushing up against you know some trees that might be on the side of the corridor and things like that and i've always been really like over the past four weeks to to be really to be really frank with you glenn like the people have been just so incredibly courteous and i don't know whether that's a more

of a reflection of this particular area because i've not heard that story be consistent across the us but here i haven't experienced anybody that's like had an issue with anything that's yelling at people that's like you know shaming them for doing something or not doing something whatever like i just i i don't i don't know what to chalk it up to but i just kind of find that people have like been pretty really been pretty curious or uh courteous about everything yeah i i think yeah most like i've heard similar stories here um i i guess the one exception is there's been a few complaints about cyclists and but you always get the complaints about cyclists and um you know so for example cycling on the pavement and basically forcing the the runner or the walker to have to go around rather than them um i think it's probably the not the kind of veterans if you like it's probably the the people who have been forced to to jump on a bike or take up cycling because they can't do what they normally do and they're just not kind of quite au fait with the etiquette of it and all of that sort of sort of stuff yeah i know in some of the bigger cycling communities here like particularly in boulder initially there was a pretty big like pushback from a lot of like the hardcore cycling community like man we don't need to follow these guidelines like we're you know we they we're not going to play by the rules you know we're going to continue to go on our group rides and stuff like that and it just took you know there's still some outliers on the edges of that bill curve

but it and it took you know three or four weeks but it just seems to like that initial pushback seems to seems to just have been depressed over the last few weeks because everybody's just starting to kind of get it you know it's not like you know it's it just wasn't like it was when when all the initial restrictions came down like people are just kind of like okay we're gonna we're gonna figure out how to live like this yeah but yeah it's i've started to get to the stage where i'm like oh when is this going to be over one of the one of the things i was really curious about people with like your area of expertise have like have you been in like like high demand are you like a hot commodity right now for because of your domain expertise yeah i'm getting a lot a lot more of interest i should yeah but it's good it's good to get out there but it's funny because just as a coach like this the this recent you know this recent pandemic which is tragic and it's absolutely you know dominating the landscape right now but to be honest with you like i've always held people with exercise immunology uh specialties in really high regard because in a nor in any in any normal circumstance having an athlete get sick is a total robber like it completely wrecks athletes you know training cycles where it not only takes them out for like this this kind of like acute phase of the sickness but also has you know tail associated with it when

they're kind of getting back into training and things like that and i think a lot of times as coaches and athletes also think about this is they think about like the big injuries that they have to encounter like the bony stress injuries and the strains and the muscle pulls and the stress fractures and things like that but in a lot of regards they don't pay as much attention to some of the other types of uh things that impact their training availability one of which is just staying healthy and not getting infections whether they be viral infections other type of types of illnesses and things like that so i've always held y'all in very high regard irrespective of the times right now but i can understand i can understand how you know your profile has been uh you know elevated to a large extent during the last several weeks yeah probably won't be for long like make the most of it while you're all right well you'll still have me for what it's worth you'll still have me um okay so i mean let's use that as a little bit of a launch point and and and kind of get into uh you and i had some correspondence uh before the podcast uh before we started recording this podcast and one of one of the things i want to do is i want to make sure i want to i want to put uh an evergreen layer to this conversation because it's really easy to get caught up in the here and now the pandemic and what can we specifically uh do about coven 19 and how do we prevent ourselves from getting infected and transmitting the disease or transmitting the virus and things like

that but for for a few reasons mainly one of which is this is really early in this whole thing and there are a lot of things that we don't know and i am trying as hard as i can to get out of the speculation game and the prediction game because ultimately it that's a kind of a fool's errand but alluding to my earlier point i do think that uh one of the one of the things that athletes can come away from this experience with is that how they treat their immune system and how they treat how they treat immune function it matters and it matters a lot in a normal year now there just happens to be like a magnifying glass on it that everybody's paying attention to because of the current pandemic but it should be it that magnifying glass shouldn't be completely lifted away once the pandemic is over it is a really really big deal for athletes to just stay healthy throughout the year in order as a means to uh to increase or sustain their overall training availability so to set the table a little bit and try to make this a little bit more evergreen why don't you just give us a broad overview of how the immune system how the immune system functions and how different components of it adapt and react to the environment and to exercise yeah i mean the first thing to start with is is i guess a definition of of the immune system and the definition of what we mean by immunity and i guess that the term immunity strictly speaking means to be

free from illness or infection or disease and the immune system has the job of of providing that or of sort of supporting that that requirement or that function so essentially the job of the immune system is to protect us from illness and infection or at least that's one of the main jobs of the immune system it's actually not the only job of the immune system but the primary function is to basically protect against infection protect against illness protect against pathogens sort of bugs and things like that which could cause an illness or could cause an infection and so it's got a number of different functions in order to be able to do that protection and or to have that ability to protect the the body it has to be able to recognize things and differentiate self-material from non-self-material or sort of potentially pathogenic organisms etc and then it has to be able to do something about those things when it has identified them and so we normally refer to this as sort of protect and recognize attack and destroy so p r a d and so it needs to be able to recognize things and then sometimes go and attack and destroy those things in order to eliminate them from the body or prevent them from gaining a foothold in the body so there's two broad classifications um to to the kind of i guess the anatomy if you like or the the kind of how we classify

the immune system and the way it functions and we usually refer to these as innate immunity and adaptive immunity um and they they're often classified as if they're two completely separate things but in reality they are part of the same system and it all works together as an integrated system and there's a lot of kind of synergy and there's a lot of integration between the the different parts of the system um but in a kind of simplistic way the innate immune system and innate immune responses are almost like the first line of defense um and another name for the innate immune system or the innate immune arm is the non-specific immune arm and basically it this is almost like the first line um and it generally has the same response against everything it's kind of non-discriminatory um and because of that it can it can act very very quickly um so it can be called into action very very quickly to try and protect the body um and in fact actually if we go back a a slight step from there um there are other physical components of the immune system and of the human body that we would classify as part of the innate immune system and this is things as simple as physical barriers um so the most obvious physical barrier that we have is the skin and that is in a way preventing these potential bugs these potential pathogens entering the body

so it's an actual physical barrier which is preventing things getting into the body that's part of of the innate immune system um but we also have sort of chemical barriers so for example some of the secretions and the fluids and the things that we secrete onto the surface of the skin onto the upper respiratory tract the mucosal surfaces and things like that some of them basically make the body less hospitable or more difficult for these pathogens to to actually enter and so that would be part of the innate immune system and if those first line defenses are breached and if if a pathogen should enter the body and basically try to take a foothold within the body then sort of the next step if you like of the innate immune system will kick in but this is still still quite rapid so we can start to activate some of the cellular immune mechanisms which are certain cells of the immune system which can basically recognize and attack and destroy these pathogens and well depending on the pathogen if it's something quite large like a bacteria then certain innate immune cells might recognize that from receptors or things that it expresses on its surface and they can come and actually destroy it um either by a process called phagocytosis and or the kind of the pac-man mechanism as i like to refer to it where they can engulf it and and destroy it um or they can release substances that will actually um destroy it without having to take it in inside of the cell um and so they have a whole arsenal of defenses that they

can basically unleash against these sorts of pathogens but if it's a smaller um particle or it's a smaller pathogen that's maybe a little bit more difficult to actually see something like a virus um for a virus to replicate for a virus to survive it actually has to hijack the machinery of another cell so it has to infect a cell of the host first and then once it's inside of the cell that's when it can actually replicate by hijacking the biological machinery of that cell that that is there to actually replicate and what um the immune system can do um is it can be targeted against those cells so it will destroy a cell that is infected by a virus and the immune system and the innate immune system can can be involved in that step as well um so there's what will happen is um in order for the immune system to be able to attack and destroy that infected cell it needs to be able to recognize that it's infected and there's two ways that it can recognize it one way is the cell um can express a protein or some kind of marker related to the virus which basically is almost like a beacon kind of flagging that this cell is infected and then the immune system can can come and act and destroy that um some viruses are a little bit more tricky though and what they actually do is they prevent the cells from expressing this marker so they're almost

hiding trying to evade kind of detection and but we have another cell and which um is highly involved in the innate immune system and something for example called a natural killer cell um and they i guess switched on to this and and the way that these virus um infected cells try to hide that they're actually harboring a virus is they don't express these markers which or they don't express the molecule which shows these markers and if these cells actually recognize that a cell is showing a lower number of these markers and that would be used to present these antigens then it will actually suspect that that cell is infected even though the virus is kind of hiding from one part of the immune system this kind of rings alarm bells that will make these other cells go and start to destroy those kinds of things um another important function of the innate immune system of course is getting rid of and basically performing this process of breaking down and um engulfing and and eliminating cells it can actually perform that in a controlled way on self tissue so for example if you've got an old tissue of an old cell that is worn out um you need to replace it and it needs to be cleared out and in exercise the kind of tissue remodeling process so when you've got a damaged tissue or a damaged cell that might be part of a muscle cell and you need to basically clear out the the old

damaged tissue in the old damaged cells so that they can be replaced with new cells well then the immune system is involved in that process that allows that remodeling so it's actually an important function and but what it demonstrates is that the innate immune system can act on a number of things and because it's non-specific you can sometimes get some collateral damage and so if that was the only mechanism that we had and if that was just allowed to continue unchecked then yes it might get rid of a virally infected cell or yes it might help get rid of bacterial infections etc etc but it could also do a lot of harm and actually when you hear about um autoimmune diseases and overreactive immune responses and things like that that's kind of a little bit what what's going on there so that's the innate immune system well before we go on to the adaptive immune system i i hope that the listeners can appreciate this description of this because a lot of times we think about our immune response being something that's very static and controlled and limited to to white blood cells which is most people's normal recognition of the immune system but when you the way that you described it like that it's actually very clever because it can recognize foreign bodies coming into a coming into a host it can and it can also recognize when those foreign bodies are trying to actually hide and adapt from the response that's that the body is then sending to them and i think that that's just something really

like beautiful and elegant about the immune system that goes underappreciated it's like how malleable and how adaptive it is to these things that are trying to invade it and cause infection yeah it's i mean it's really fascinating and and i mean if you even like the white blood cells are one of the main components of the immune system and there are billions of them it's it's hard to kind of fathom sometimes there are billions of them in the body but there's lots of other tissues and molecules and and things which help it communicate it's really quite vast it's it's such a complex system and and the way it works when it works well and it's an integrated response with lots of different components all acting together in concert um is yeah it's really quite amazing i think so let's move on to the adaptive component then you did such a good job of explaining of explaining the innate component i can't wait to hear this piece of it yeah so the adaptive immune response um or you will sometimes hear this refer to as the specific immune response so the innate was non-specific the adaptive is specific and this one takes longer to develop um or it takes longer to actually kick into action and so it's it's not quite as quick but it is it's much more targeted and much more specific so it's kind of good that the innate immune system can kind of almost hold the fort whilst the adaptive response is actually kicking in and establishing because it can

take several days or even several weeks for the adaptive immune response to a novel or new exposure to actually fully respond and sort of fully activate and there are a number of different components but probably the most notable components are are certain types of white blood cell of the adaptive immune response and they will so when i talked about for example a virally infected cell um you can have the innate immune system recognizing that cell maybe going and starting to to sort of do some work on it but at the same time it will release substances which will signal to other components of the immune system um and these are the components of the immune system might kind of come and and have a an effect and have an action on clearing those and so the first exposure the adaptive immune system will actually take quite a long time to respond but one of the things that we have that is different in the adaptive immune um system or the adaptive immune response is something called immunological memory um and basically this is where after an initial exposure which um takes a long time for the adaptive immune response to kick in it it almost remembers or it kind of so basically what happens is the the cells of the adaptive immune system will proliferate they will divide and they will ultimately become a specific type of cell which will have a specific function and so some of the functions that we associate with the

adaptive immune response are the production of antibodies for example um and antibodies are specific these are like your sharpshooters if you like they are not sort of um non-specific and they don't have all of the collateral damage that you would associate with that you would associate with the innate response and they are targeted to a specific often protein um or or something that might be associated with the virus um or a pathogen rather i should say um and antibodies can basically bind to a pathogen and either prevent it from attaching or prevent it from essentially infecting a cell or prevent it from replicating and but every pathogen which might be primarily comprised of protein is is going to be different in its structure so the antibodies that we produce are specific to a particular protein or a particular sequence or something like that so one antibody will work on one target but it won't necessarily work on another target so we have to have specific antibodies for these specific things um so by producing antibodies it's it's one of the defense mechanisms that we can have to basically stop replication of pathogens and stop them really infecting the body and this is slow to develop because the immune system has has to recognize it it has to divide it has to develop it has to initiate and the production of these substances but once it's done that once um you basically have memory cells if you like

which which which basically stick around sometimes for life so that if you encounter the same pathogen again they're already there so you don't have you basically can can sort of bypass the initial steps and move straight to one of the kind of further steps in the process that means the second response can be a lot quicker and you can basically usually neutralize or destroy this pathogen before it actually has a chance to infect the host and this is exactly the principle by which a vaccination works so um or naturally acquired immunity so if you vaccinate somebody you're basically exposing their immune system to either an attenuated version of a of a pathogen an attenuated version of a virus or a protein that will be a protein from a from a pathogen from a virus which allows the immune system to develop this memory so that when you actually come into contact with the real disease the immune system responds so quickly with a specific response rather than an innate response per se and therefore it's able to neutralize or eliminate it before it actually infects the body and that's come into the popular news into the kind of the mainstream media right now because one of the things very specific to uh covet 19 is is we don't know if somebody has the antibodies to the virus if they are then in fact immune that's one of the things that a lot of the

virologists are trying to figure out right now just because you have those specific antibodies doesn't mean that you're immune from from infection or reinfection yeah and that's a that's a tricky one i don't i don't know the answer that one i'm afraid but um it it could like generally speaking for viral infections um if you have the vaccination your body then if you have a good response to the vaccination because not everybody always has a good response to the vaccination but most young healthy people have a good response to most vaccinations if you have a good response to the vaccination it normally will provide protection what we're unsure about with regards to something like covet 19 is will you get full protection um or could you still be susceptible even so is the vaccination going to be effective when we look at other respiratory viruses um i mean you there isn't a vaccination for the common cold um partly because it's not that serious so there's not that much of a desire and there's not that much money in it for the big farmer who who would develop these um vaccinations and but it also there's so many different strains of virus there's several hundred um viruses that could cause a common cold so it's a really difficult one to to vaccinate influenza so the flu we have vaccinations for that but you have to have them every year because the strains

change and you're vaccinate the protection that you get from the vaccination is only specific to the strain that you're vaccinated against they are trying to develop a universal vaccine but they're not quite there yet for influenza so it could it be with covid that there's different strains that are emerging so just because you have protection against one you don't have protection against another or could it be that um it's actually able to reinfect the same individual even with the same strain and we don't i i don't think we know the answer to that yet because it's so novel and so new um but it's it's i guess just talking about respiratory infections in general it it makes you realize that you you might have immunity to one thing but it doesn't necessarily mean you have immunity to another so it can be a yeah complicated and tricky area yeah let's steer back to what we kind of know a little bit more of since uh since covid is so new and we could go on for eons about this but i i mentioned from the onset that when athletes get upper respiratory infections it is a killer and i i personally as a coach i bang my head against the wall when this happens because i know they're missing training time and i also know that there is likely something that could have been done in the training process to help protect the athlete i view it as a little bit of programming error that could have gone into some component that created uh that infection and i want to get into both of those but to set the table on that let's go over some like

really just generalized incidents reporting amongst athletic populations in terms of how often are they getting upper respiratory infections in any other normal year not 20 not 2019 2020 let's go back to like 2018 2017 2016 like things like that what do we know about how frequently athletes are becoming infected i mean if we're talking about just upper respiratory infections um so things like the common cold is the most common one the flu a little bit and if we talk about those types of things um upper respiratory tract um and if we start with what's normal for a non-athlete so what's the normal incidence in the in the general population i mean it does vary um across the seasons and it does vary from year to year so you do have years with pandemics and with epidemics not just like this year but you know we've had other flu epidemics and flu pandemics in previous years or we sometimes just have a year where it is just a normal common cold but you know it's the year you remember that year when everybody got it as opposed to another year when nobody had it so i'm kind of saying this as a approximate rule of thumb as a kind of a bit of a rolling average over several years um but obviously bearing in mind that you will get spikes some years compared to other years and you do tend to get spikes um certainly in the northern hemisphere you tend to get spikes around the winter months um so sort of december or november

december january february um sort of time or whenever the winter season is and wherever you are in the world so it does vary across seasons as well but an average person will typically pick up about two or three of these sorts of infections and or they will report at least two or three of these sorts of infections in a typical calendar year um somebody who is just regularly exercising and is meeting the kind of general health guidelines probably about half that amount and again this is on average we've obviously this is the middle of the bell curve and and we've obviously got the outliers and we've got the full distribution this so i'm just talking about the average right right in the middle here um and then athletes or people with a higher training load um they could be very similar to a regularly active individual so they could have a lower reporting incidence or they could be all the way over to the right of the curve um and actually be reporting much more frequent incidences so if somebody's reporting four or five episodes per year we would normally classify them as moderately at risk score a moderately illness prone athlete if they're getting more than five and there were a couple of papers where um top level athletes are reporting between 10 and 12 episodes per year then we would classify those as highly illness prone athletes so you can get athletes who who report these things a lot even in athletes you might look at them and or you might look at their data and they might not report

any more in terms of their total incidence per calendar year but if you look at when they occur they can also tend to cluster around certain times winter can be a cluster point but also intensified periods of training or competition can also be a cluster point and if it's in the run into a big event that you've maybe been preparing for for a long while then obviously that's the absolute worst time to pick up one of these and that happens a lot because a lot of times athletes are intensifying their training in the last few weeks leading up to event and in addition to that i always think that this is another confounding factor that doesn't that isn't really fully appreciated in a lot of the studies they're traveling to the event and coming in contact with other people other sources of infection and so their exposure risk goes up simply because of that increased contact and that increased travel that they're having uh in the weeks leading up to the event um what so what you're describing a lot of people will recognize as the j curve which has gotten a lot of attention in athletic circles and it basically describes if you're a non-exercising individual you have a certain risk two to three times a year of getting an infection if you take the in the us or i guess worldwide would be the acsm health and fitness guidelines for being quote-unquote healthy you're going to reduce that risk by half but if you train in most athletes and our audience are athletes and they're going to be in kind of in this latter category you can actually have an increase in

your risk or your incident rate of having an infection and so when you plot those three points over a continuum from not exercising to exercising to training from left to right it kind of plots this j curve out is there any other kind of like nuance or caveats with this j curve that you think athletes would be well served to to have some information on yeah i think it's i mean that's the stylized model um right there have been some people who have questioned this um and i mean maybe we'll have a chance to talk talk about the different opinions on this um in in a little bit but i guess the one thing that i would want to point out is that and maybe this when people question it maybe they're not fully understanding understanding that the sort of the nuance to the model and that is that it's a simplification and it's got two dimensions okay and you've got your x-axis here with training load or amount of stress physical stress or whatever and one of the important points that i think it's really important to point out is that you don't you're not fixed to a particular point on that x-axis so an athlete at different times in their training cycle in different parts of their periodization plan they might move left and right across that curve um the other thing is of course it's only considering

physiological demand of exercise but that's that's what i mean by one dimensional or that there's this one dimension in that axis if you like but in reality in in real life with an athlete there's a whole host of other factors um confounding and contributing variables that also have an interplay with this relationship so it's not just physical stress but there's lots of other stresses it's psychological stress it could be environmental stress it could be general life stress and it could be related to work it could be related to relationships it could be related to that you know there's there's a whole psycho physiological area um it could be related to travel it could be related to nutrition there's there's so many other factors that it's hard to untangle them all and look at them all separately and individually um so what we need to remember is that the amount of training that an individual does is one of the contributing factors but it's not the only factor and when we're dealing with a real person in real life not a laboratory animal who you've got absolute control over then we do need to be aware of of all of these other factors and the other the other really important thing there is the i guess the other component is how the immune system is functioning so what are you doing that is

influencing the immune defense the kind of defense side of the equation um and that that says how strong your defense might be should you be exposed to a to a pathogen so how able your body is to fight it off if you come into contact with it but you have to come into contact with it in the first place so the exposure is a massive confounding factor it's a massive risk factor that is sometimes overlooked it's really difficult to manipulate exposure in in the research that we do on on this to try and understand this relationship it's it's very difficult to control the exposure um what we normally try to do is take information from sufficient people so that we've got a good representation of the whole population um in animal studies of course they can control exposure and they they will sometimes um challenge animals with a with a virus so they will expose them intentionally to this virus and that has been done in human studies um as well but not with exercise um it's normally done in pharmaceutical companies where they're sorry pharmaceutical studies where they're testing medications or vaccination efficacy and and so on um and it's really difficult and very very expensive study these are multi million dollar studies and the cost to do these um so obviously quite different from your typical exercise science study um so the the relationship is a the j curve that you talked about is a is a nice model

and i think it's a nice stylized representation but we always need to be mindful of the fact that there's lots of other things that that come into play at the same time yeah 100 and your point on exposure i think should be well taken and it's kind of like a no duh statement like of course you have to have exposure to a virus to get an illness from it but in this time people are forgetting that and they're and they're starting to think about okay what are all the ways that i can boost my immune system we're going to come back to that in a little bit the body's response and how you can support a healthy uh immune or how you can support a healthy immune response but in turn but in terms of exercise even if you knocked the immune system down if there's no exposure there's no risk now that's a big statement having quote unquote no exposure but if you look at a lot of the the the quarantine the self-quarantine the social distancing and things like that all of those measures are in an effort to reduce the exposure from person to person to person yeah definitely and i mean that was obviously that's one of the biggest controllable risk factors right um from an athlete's perspective is what what can you do to minimize your risk of getting ill well you can minimize your your exposure and you know several months ago we would have probably thought that it was like completely ridiculous to to totally reduce your your exposure and essentially live live in quarantine if you like um but i mean it's difficult in in when

we're not in a situation where we're kind of in a in a lockdown or something like that it's for an athlete even if they are a professional full-time athlete it's still very difficult to completely eliminate exposure um and if they're not a professional full-time athlete they've got a life to have they have to go to work they have to get there somehow they have to potentially interact with people at work they might have kids and kids are great at you know bringing back illness from school and spreading it around and stuff like that so although a pragmatic recommendation is to minimize or try to reduce your exposure sometimes it's really difficult to do that in the real world when you have a life to live and but if you can minimize it as much as possible then you can obviously minimize your risk or if you can minimize it at the times when you know you are most at risk um then obviously you could minimize your risk um further so being pragmatic and trying to integrate that into something that's workable for the individual and everybody's going to be different in what they can and can't do so i think that that's probably um the best strategy though is is minimizing your risk as much as is feasibly possible for you or for that person yeah for our elite athletes that travel around a lot and have to interact with uh fans and people in the media and other athletes and support personnel and things like that they're constantly coming into like interpersonal contact with uh kind of with other individuals from all around the world especially during the competition season we have a little

punch list of stuff i should have pulled this up right before the right before the podcast but we have this little punch list of stuff that they need to be cognizant of when they're undertaking those travels and it goes everywhere from hey do a fist bump instead of a handshake and now that would even be considered taboo right it's like six foot fist bump or something like that two meter fist bump um but it'd be you know do a fist bump instead of a handshake and carry your own your own pin around if you're signing autographs or if you have to sign any other documents and things like that wash your hands don't touch your face like a lot of these things that um uh that that are now coming to light on the side of exposure and reducing your exposure those can be considered a lot of them can be considered healthy habits for forever even once this virus is kind of under control when we go through our normal flu seasons and things like that we can take a lot of these lessons that we have learned through this time and apply them to the future so that athletes don't get sick even in normal times and i think one of the one of the things that we've learned i think from the kind of the current pandemic is that it's actually possible i think it's probably made people realize how some of those um minimizing exposure strategies are actually possible like some of them when when the world goes back to normal if ever that happens hopefully soon um sort of beforehand some of those recommendations about you know avoiding ill people or you know um minimizing our exposure some of those you would just say well

that's ridiculous you can't do that it's not feasible but one of the things that this has shown us is that it can it can be done so individuals if they know that they're at an increased risk for a period of time they could at least try to implement similar strategies as much as possible during those risk periods and then the other the things that we're seeing about hand washing and um we've i don't know if it's been the same for for you guys in the us but in the uk we've had all of these um health recommendations about effective hand washing technique um and you know washing it in a particular way for a certain amount of time and using the right method and how many people did that before and actually that that could be such an effective strategy because one of the biggest ways of infection is essentially self-inoculation whereby you've picked up the pathogen from something that you've touched or from shaking hands with somebody and then you introduce it into your body because you touch your nose or mouth or eyes or some other route of entry that's and that's brilliant i think a lot of people are singing happy birthday to themselves while they're washing their hands and it might continue to go on um let's kind of come back to the athletic side of things uh again i know a lot of athletes are living in a little bit of of what i would call like reasonable fear about what happens to their immune system after they go and do a workout particularly if that workout is hard and or long and a lot of the dialogue around this kind of revolves around this open window hypothesis uh that uh that that's

been floating around the athletic circles for for several years now why don't you review what we know or what we think the open window hypothesis tells us about immune system about immune function immediately post-exercise yeah so the the open window hypothesis is that certain types of exercise so if the exercise is intensive and or prolonged enough then you will get a period a short period after exercise so in the recovery phase when immune function is reduced um now this isn't usually what we would consider a clinical reduction um so it's not it's not massive i i guess would be one way of saying that um but it might be enough to lower your defenses just a little bit to mean that if you were exposed to something that's going to cause a an illness that you're now less able to fight it off than you otherwise would be so the theory is that for several hours um maybe sometimes a little bit longer it depends how hard and long the exercise was the immune system is knocked down a little bit and this is referred to as immunodepression or exercise induced immunodepression and it's this period of immunodepression which is basically reducing those defenses which means if you're exposed you might be less able to fight it off um so that's what the open window hypothesis is and the open window hypothesis exists because lots of studies have been done where they measure various markers of immune system function

function so the classical ways of doing this in the kind of older studies would be to take a bodily fluid sample so the most common one would be a blood sample um or a saliva sample and then measure markers in those samples which give us an indication of of how well the immune system is functioning so that's the hypothesis so that might be for example you count the number of the different types of white blood cells and then you add something to the sample which will stimulate those white blood cells to actually initiate their function or to behave in the way that they would behave if they were encountering a pathogen in the body and then you measure that response in various ways so you're almost testing the immune cell's ability to unleash its arsenal of attack and there's been lots and lots and lots of studies that have measured various components of the immune system and many of these components have been shown to be reduced a little bit for at least several hours after very intensive and or prolonged exercise so that's the theory the problem with it is that in traditionally in those studies the way that we've assessed the immune system is by taking a sample from outside of the body so it's no longer in its natural environment so can we really translate that into what how it would respond when it's in the body encountering a pathogen and also we are only accessing the components of the

immune system or the cells of the immune system that are either in a saliva sample or in a blood sample but that's not necessarily where where they are working when they're in the body so you've taken them out of their natural environment is the first problem and the second problem is we tend to measure one or two or three or four or maybe even 10 or 20 or 30 different things but we measure them all individually whereas in reality there's there's many dozens of different functions and different components of the immune system and like i said near the beginning they all need to work together in a synergistic and integrated way so it's probably a little bit of a leap to to look at a single marker of immune function or a single cellular response and say this is reduced by 30 or 40 that means that you're definitely at an increased risk because when one thing goes down that could be compensated for by an increase in another thing and we do have a natural redundancy built into the immune system it's it's a really smart system so it's it's complex for a reason it's complex so that you know if you have a deficiency in one area you can sometimes compensate for it with um adequate or or higher levels in another area so it's translating the individual changes in specific markers to a genuine clinically relevant risk is is actually difficult and

you could i mean even if you could measure absolutely every individual component of the immune system out of the body in a in a lab in a test tube how do you mathematically put them all back together to understand how they would all work and integrate together is is is almost impossible so what what that basically means is the problem with a lot of the historical research is that the markers that we've been traditionally relying upon are not necessarily indicative of risk of illness now obviously if you've only measured one thing and that's gone down then you don't know what's happened to the rest of the immune system if you've measured 20 things and they've all gone down you can probably be a little bit more confident that that's not going to be good for your risk of illness or infection but the other thing that it doesn't take into account is could it be that the the cells that we're really interested in you haven't picked them up in the blood sample because they've gone off to where they need to be they've gone to the lungs they've gone to the respiratory tract they've gone to the gut they've gone to these places where they're needed so you're not actually measuring cells that you that you should be interested in yeah redirection so to speak yeah yeah so but it doesn't mean that it doesn't exist it just means that that when the what we thought was strong evidence in the past is not necessarily strong evidence now and we're now starting to appreciate that that we need to try and measure the whole

system working together in concert rather than individual components and there have been several studies where where we have measured um some indication of the whole system working together in vivo so markers where you're not taking a cell out of the body you're actually applying some kind of challenge to the body and you're you're measuring how the immune system responds in vivo in the human body in the real world in real life and we still see with those markers we do still see that exercise does reduce it um so there's definitely an open window um i guess where the debate is at the moment is how significant is that at contributing to your risk of of getting an illness and i mean it's almost impossible to to put specific numbers on that but my argument would be that it can't be a good thing we we know that the function of the immune system is to protect against illness so if when you look at it in a whole integrated way if we're seeing reductions it would probably be better to not have those reductions in terms of your defense against getting ill that's a really good synopsis of it is we know that there's something going on but we don't know its clinical significance and the dialogue that um that you went through regarding the specific markers and their individual contributions to this whole immunodepressive uh aspect i think is really brilliant and this happens all of the time in physiology

in biochemistry and nutrition where we pick out one really specific thing whatever it is you know and we say ah well this marker is going up or it's going down or it's going sideways and therefore x y and z happen and the therefore piece as you mentioned in almost all cases is a really big leaf of faith to take one very specific marker and then extrapolate a physiological process that encompasses hundreds or thousands of different various you know biomarkers and processes and in chemical pathways and things like that i just look at it and i shake my head and i'm like no it's like not that simple like it's really really complicated you can't always look at one specific thing and extrapolate that something is happening in the body to a global level yeah that's i mean that's i i totally agree with that and and i have very similar kind of thoughts when i when i sit not not just in immunology but in in physiology in general and there's it can go both ways it can kind of be there's a there's something that increases um we see a lot of it in kind of training physiology where you measure a particular marker you measure the expression of something and it's gone up by 500 on this condition as opposed to 300 that it normally goes up and we say oh well that means the 500 is better but is it because could it be that once it's gone up by more than 50 everything above that is the same right and and and it could be

the same from the kind of immune system in terms of okay we've seen a 30 decrease or a 40 or a 50 does that matter um is anything below you know anything greater than a 20 the same or is it is it that it doesn't matter until you get all the way down to like over an 80 decrease and anything up to that is okay and it's kind of like a threshold concept and we just don't know for many of these things where that threshold is and the like is it a linear gradual kind of proportional relationship or is it a threshold and you know the tiniest amount above and below is where the difference is and going beyond that doesn't alter so yeah yeah it's really interesting the over interpretation of biomarkers now has just gotten in but this is a tangent that i'm i'm actually going to bring a guest on in a few weeks it's sean arent out of rutgers university and we're going to talk a little bit about biomarkers but i really want to shed some light on my what what is my opinion that we are over interpreting in many cases what these biomarker movements actually practically mean to people that's another conversation let's let's bring it back to let's bring it back to immune immune function um one of the fascinating feet one of the fascinating features of immune function is how it gets supported just through natural you know natural things that you can that you can do and i one of the things that's uh that's kind of emerged out of this covet 19 pandemic is i think a better understanding that

something to you something that you alluded to earlier that you can support a healthy immune function and that's typically the right and uh kind of broadly regarded vocabulary that we should use when we're describing immune function that you can support a healthy immune function but you can't quote unquote boost it which now i don't know what your instagram and twitter feed look like now but i am getting inundated with immune boosters quote unquote immune boosting supplements from everywhere and that is my bullshit detector like once i see that word immune booster i just automatically i can ignore this but i i want to i want to kind of bring this back to to something more practical because nutrition can can absolutely impact and support a healthy immune uh healthy immune system and by nature of um what ultra runners do run for long periods of time they're going through some acute phases of low energy availability which can affect immune function they're going to have to combat this from a nutritional perspective uh to a certain degree so why don't we just first go over like what are some of like the big nutritional no-no's that athletes should be avoiding that could severely impact their immune function the biggest one is nutritional deficiency of any description um it's probably the biggest detrimental

nutritional nutritional practice that that can you know have a negative effect on the immune system and therefore the risk of illness and and this is this is really important because it's for most people it's really easy to avoid deficiency by having a healthy and varied and well-balanced diet so if you do that and if you avoid nutritional deficiencies then you will have a normal healthy immune system and i think when we when we see or hear terms like immune boosting um in relation to nutrition what they are some again it's it's this over extrapolation right what they might be describing is what happens when somebody is deficient or they've got a problem and when they correct that problem and if you've got a deficiency that's going to have a negative impact on on your immune system and how your immune system is functioning and therefore your risk of illness and if you correct that and improve the diet to what it should have been then that will increase it and make things better but really what that's doing is returning them to normal so people are interpreting that improvement as a boost but i don't think we should be seeing it that way i think we should be seeing it as that should be the point of reference that's where people should be and it's the same with physical activity as well that's we shouldn't be sedentary so we shouldn't be using sedentary as the point of reference we should be using healthy in terms of both physical activity and diet and nutrition

that should be our point of reference and you can be compromised if you're not following that kind of healthy balanced diet healthy activity levels etc etc and if you correct that it's bringing it back to normal and again this is another example of where over extrapolation can occur people can then make an incorrect assumption of you know if i'm deficient in this nutrient and there might be quite a high prevalence of deficiency of certain nutrients in certain populations and then if i correct that deficiency by supplementing or sort in my diet it's going to bring me back to normal which looks like an improvement so they think well if i take loads extra then that's going to cause even further improvement and boosting in inverted commas but usually what's the case is you don't get any additional benefit once you've got the requirements for you as an individual then adding extra intake on top will normally not do anything further in in terms of benefit i think probably the thing that may be interesting for athletes is what is that normal healthy requirement the normal target if you like of what is required for certain nutrients for an athlete is probably for most nutrients is probably a little bit higher than what it is for a less active individual are there some heavier hitters though in the nutrition space just in terms of either the total amount of calories that uh that an athlete needs to make sure that they cover with their exercise and obviously their their

their basal metabolic calories that they needed or specific macronutrients or specific vitamins that are really specific to immune function yeah um i mean totally probably the biggest one is is is energy availability or total energy intake so if you're in significant negative energy balance um that seems to have a very big negative impact on immune function and illness risk if you are in um negative protein balance as well um that can can be quite a biggie um we used to think negative carbohydrate balance or sort of low carbohydrate availability we used to consider that a bit of a risk factor um but again going back to when we were talking about most of the evidence on carbohydrate is based on these individual markers that i talked about a little while ago which are maybe not the most clinically relevant markers when we actually look at evidence using clinically relevant markers and there's a few more of those these days um it seems to be that actually low carbohydrate availability isn't as big a deal in terms of risk of illness or changing clinically relevant markers as we thought it was um as long as you're getting total energy and all of the other nutrients in abundance so maybe some of the older studies where we thought low carbohydrate availability was a bad thing maybe it was because by having low

carbohydrate availability at the same time we were having low energy availability and maybe even low low protein availability so total energy intake and meeting total energy requirements i would say is probably the most important one and and then micronutrients deficiency of things like zinc um vitamin c vitamin d um are probably the the biggies where if you were if you were severely deficient in those then um although it is quite hard to be deficient in some of these things and but yeah they could certainly be um bad i guess for immune health and vitamin d specifically has got a lot of attention uh recently and it's also one of the more kind of complicated uh vitamins being a fat soluble vitamin that you can actually overdose on um if if an athlete doesn't have you know good sun exposure good exposure to the sun uh on their skin or is there anything that they can do to like improve their vitamin d levels i mean you can supplement um and there are um i guess there are accepted intakes um you probably have a sort of i don't know if you have a would it be fda with you guys or yeah yeah so there's probably um like so over here i think it's kind of 4 000 ius per day is considered safe which is actually really really really high um i i

certainly wouldn't wouldn't sort of see a need unless you were severely deficient to be supplementing with with that level um but so it is reasonably safe to supplement with a moderately high dose and the evidence out there suggests that um it is safer to have moderate amounts daily rather than really really large amounts with bigger gaps in between and but what i would actually personally recommend is that it's it's pretty pointless unless you're deficient so if a if you're able to to get screened and get checked out so if you're able to to get a vitamin d level of a vitamin d status check um then it would be worth doing that before in order to inform your decision about whether or not you should um consider supplementing and because if you are deficient it obviously can be beneficial and also it it will probably need to be rechecked as well because you might be sufficient in the summer months but you might be deficient in the winter or you know you might right be deficient you might be severely deficient so you might try to supplement to get back up to normal but you know you would you wouldn't just assume that it was happening you would have to have a kind of recheck to make sure that it's happening so i would say if you're considering it and if if if you're a serious athlete um and if you think you may be at risk of deficiency just just get it checked out it's it's reasonably cheap to to get a

vitamin d screen outside of that is there are there any other supplements that you would recommend specific for immunity so there's there's i mean there's a couple of things that there's reasonably good evidence for that and i think the big caveat that i always add when i'm talking about supplements is that we need to be careful when we interpret the evidence because one of the biggest problems that i see in nutrition research is that you will sometimes see papers um you will see published research suggesting that this supplement has a benefit or that supplement has a benefit but when you actually read the methods of the paper what you find out was that they didn't actually report or they didn't screen their participants to see whether they were deficient in the first place so what happens if they were deficient then they give them a supplement that corrects that deficiency all you've done is shown what happens when someone's deficient and you correct that deficiency but if they didn't know that then the study could come to an incorrect conclusion that taking more of this particular nutrient or this particular supplement is beneficial so we need to be careful when we look at the research to see whether are we confident that it is really showing us that taking extra above what you're getting from a normal healthy diet is providing that further benefit and most of the time the answer to that question is no so if we know if the diet is already well balanced and that should be what we aim

for first if we're not experiencing any nutritional deficiencies can you get any further benefit by adding stuff on top of that diet that basically provides further benefit there's a couple of things um one of the i guess one of the most popular ones or one of the most popular types of supplements are things like probiotics um and there's reasonably good evidence for probiotics um and again obviously you might get some probiotic type bacteria in a normal diet but you're not really going to be getting the same amounts that you would get from taking a supplement um and there's reasonably good evidence that the dosages that you would use in a supplement study where you would take a daily probiotics um supplement do actually provide um benefits and reduce the risk of illness and there's been a couple of pretty large-scale studies where they monitor athletes over you know several months they have a well-controlled placebo versus active and they actually see a lower illness rate in the individuals that had the probiotics so i'd say that there's reasonably good evidence for probiotics and also another thing to balance up is the risk versus benefit and the risk for probiotics is is very low um assuming you know often these are provided via dairy products fermented milk products and so on um so if an individual doesn't have any allergy or intolerance to dairy then things like um probiotics have got reasonable reasonably good

evidence that you could get additional benefit from those with very little risk um other things like we talked about vitamin d there's there's not really any evidence of that being useful unless you're deficient um the antioxidants and antioxidant vitamins again there's i would say the evidence is weak for those um and it's it's a bit of a kind of old wives tale you know have you know load up on vitamin c and stuff like that there are some old studies suggesting that there might be a benefit with really high doses of vitamin c and but again they didn't necessarily have or they didn't necessarily report what antioxidant status was like before they supplemented um so and and also there's a risk with high dose antioxidants that they could blunt or interfere with training adaptation and the physiological adaptations so i'd say those kind of things the evidence i would i would argue was pretty weak um what other things yeah the antioxidant the antioxidant supplementation ship has sailed i think it's it's i interestingly enough i grew up right next to the cooper aerobics center in dallas texas and king cooper was one of the original researchers in a lot of the high antioxidant types of research and uh i spent some of my teenage years actually there doing what was kind of a combination of a very very very very low level internship and some and and some summer work so i i've i've appreciated his work for for a very long time and it's been interesting to see the tide turn so to speak on the

antioxidant side over the last several years other things i mean i've done some research myself on bovine colostrum and we have seen quite notable changes in or quite notable differences between a placebo and a bovine colostrum groups in the risk of getting ill in athletes and in in sort of periods after intensified training and stuff like that um but one of the i guess controversies if you like or one of the the sort of problems that we have right now with um with bovine colostrum is it's it's quite high in igf1 um and and other growth factors so um wada the world anti-doping agency actually have issued a sort of slightly unusual statement they've actually had it um they published it for a few years now um because bovine colostrum is a is a natural dairy product it's just early milk um and so they their statement is something along the lines of it's not banned um but because it's quite high in igf and growth factors we don't recommend that you use it so it's it's in a bit of a gray area and it's a little bit confusing i mean interestingly the the that was based on some research that suggested that if you take bovine colostrum it will increase your blood levels of igf1 um but there was a number of problems with that research and lots of other research that has followed hasn't been able to demonstrate that and actually if you just drank a you know a couple of liters of milk you'd you you know or or took about

40 50 grams of whey protein you'd actually get the same dose of igf and it's basically just broken down in digestion like any other protein um so that one has got good evidence but i'm always very cautious of recommending it given what wada have said and you know if somebody did take it and then go and test positive for another reason and try to use that as an excuse then it would probably paint you in pretty bad light or put you in a in a difficult position um so unless wada kind of revised that statement i think i think we need to be really cautious with recommending things um like that and the other things there's been a lot of interest in like polyphenols and and um you've possibly seen some of the work that's been done on quercetin and which is a type of bioflavonoid um and there's been some studies showing that um high dosages of quercetin and like like one gram a day one and a half grams a day which you couldn't obtain from a diet i mean it's quite high you'll find it in things like onions apples teas um etc and but you couldn't get anywhere near that dose from a normal diet and there's been some studies suggesting that that can reduce the illness risk but there's also been some studies showing no effect so that's a kind of maybe some evidence maybe oh well mixed evidence i would say yeah the i mean the big thing to take away from this is is make sure you have enough calories

and you're deriving enough nutrients from those calories and then you can if you wanted to add some like small pebbles to the wall maybe some vitamin d maybe some probiotics you know maybe some of this maybe some but but don't forget don't use those to cover up the big rocks which are total calories and the nutrients that come from yes absolutely yeah good analogy that one i think yeah yeah yeah okay let's um we're gonna let you go but but i i'd be remiss if we didn't go over two like folk folky types of uh uh quotations or phrases that commonly come out when all of these illnesses go around and i want to get your your your quick take on them and i love these because is as as eloquent and as thorough as you've tried to as you've tried to be in the last 75 minutes or something like that which is which is quite amazing i don't think i think it's underappreciated how much time effort research reading goes into kind of having the knowledge level that you have but in a lot of ways sometimes it can be boiled down to some really simple phrases so i want to get your take on those the first one is feed a cold starve a fever interesting um there's there has actually been some experimental evidence on this um but but but the actual findings are mixed i i think um certainly for the the feed a cold i think comes

from the evidence that the way that the immune system responds to a viral infection um would actually benefit from having energy and nutrient availability and and there was one study i think that supported that but i think there's also been studies that refute it so i would say as a short response to that there might be something in it but it's still a mixed bag of results unfortunately okay fair enough okay the next one and this is what this is one that a lot of that a lot of athletes have heard because it's easy for coaches and people in lay media and things like that to kind of regurgitate training if your symptoms are above or below the neck why don't you just take us through like the whole the whole arc of why that might be a plausible piece of advice to give somebody and then what yeah it's actually um quite well accepted that one um and it's generally speaking it's kind of separating the more upper respiratory from the kind of more lower respiratory sorts of symptoms and therefore the likely cause of it and basically the lower down ones are a little bit more severe usually um and a little bit more dangerous and you normally feel a little bit more worse that if it's mild again it at the same time you have to balance in how the individual feels and how bad those symptoms are so it's not just as simple as where they are but it's also how bad they are as well but generally if it's above the neck

only and if it's mild and so if it's just a head cold runny nose a little bit of a sore throat then it's usually considered safer to continue with moderate training and that's the important thing to continue with mild training um i love all the caveats if it's mild it may be safer safer not safe safer to continue with moderate not regular moderate training anyway all the caveats aside keep going yeah but i mean i think it is important because athletes we know i mean you know many of us i would consider ourselves athletes maybe a more recreational level but you know what we are like we don't want to stop and and we do silly things um sometimes and actually that can be really really dangerous so um i guess that's the reason for all of the warnings and the and the caveats um but yeah if and and sometimes you know athletes will take things as black and white well right you know you've said this above the neck rule so i should be able to continue doing that 100 mile maximal effort but yeah they need to put a bit of judgment on how they feel that the the the body will you know i guess not thank them if they've if they've pushed it when they're unwell what that could mean is actually it means that it takes you longer to recover in the long term and then you spend more time out or you get more ill and you lose more rather than get that benefit from doing that one extra little half of

a session or something like that so maybe we can change it to above the neck proceed with all of these different caveats you can have normal training load maybe a little bit worse as long as you know the symptoms above the neck are not that severe but below the neck what are the caveats and things there is it total stop like hard stop like don't even think about it or what is your thought on it i would say hard stop um in order to review because you need you need to re-evaluate each day and and see which direction your your trajectory is going if it starts to improve um and if the symptoms start to subside you you could possibly think about easing back into it um but you really do need to ease ease back rather than jump straight back into exactly where you left off before yep awesome great advice man all right we're gonna let you go on behalf of the listeners we really appreciate your time and really appreciate what you do not only during this time during this pandemic but like i said as a coach i've always appreciated folks like you's work in the field because it helps us and it helps us just be better informed on what to do day to day in different illness cycles and things like that so thank you thank you very much can you tell everybody where they can reach you or learn a little bit more about the research that you do yeah absolutely if you do a google search for me so if you just look up glen davison university of kent uk um that'll take you to my home page it's got information on there about

the research that i do it's got links to my latest publications and it's obviously got my contact details um i'm also a member of the international society for exercise immunology and the uk society for exercise immunology so if you look either of those two up you can probably find my details on there as well awesome glenn appreciate it man this is great i know everybody's gonna appreciate it yeah stay safe out there okay all right trail runners that was a hoot had a really good time with that uh like i said i really appreciate glenn's time and effort that he put into this coming to us all the way from the uk which is a much different situation than we are than we are at right now but i do think and i do hope one of the things that you all come away with this conversation with is that a lot of the things that we are learning right now through the covid 19 pandemic we can really apply for years and years and years to come the uh kind of the hygiene habits that we take away the way that we can keep ourselves healthy uh keeping a healthy diet washing our hands not self-inoculating these are things that we should think about every single year when the cold and flu season starts to come around and if there is a silver lining or one of the silver linings that starts to emerge out of this pandemic it says we can take these habits and kind of roll them forward to keep everybody happy safe and healthy for years and

years and years to come i hope all of you are staying safe and healthy out there i really do hope that we get to see you out on the trail someday if you like this podcast go on over to itunes and give it a like or a review that helps the podcast out a tremendous amount appreciate the heck out of everybody listening we'll see you at some point until then stay safe stay healthy have a great time on the trails if you can get out to them if you can't keep yourself healthy keep working out do whatever you can to keep the ball rolling we will see you next time you you you