Training and Nutrition for Hot Environments with Alan McCubbin, PhD | KoopCast Episode 34

what's going on trail and ultra runners welcome to another episode of the KoopCast a podcast where we explore all areas of ultra running including training racing nutrition physiology psychology as well as have a little bit of fun banter along the way all in an effort to help you become a better ultra runner as always i'm your host coach Jason Koop and on this episode of the podcast we have sports scientist alan mccubbin out of melbourne australia alan is a PhD as well as an accredited sports dietitian with a specialty in nutrition for endurance and ultra endurance sports he's been a practitioner for over 15 years and founded his own online business next level nutrition in 2010 and offers consultations to athletes via video conference his clients have really included everyone from first-time marathoners to summer and winter olympians alike and he is also a consultant to triathlon australia's high performance program he has published a number of different research articles including a case study on the 2016 marathon de saab in a recent position stand for sports dietitian australia on nutrition for exercise and hot environments which we reference in this podcast he is also a lecturer and a researcher in sports nutrition at mansa university in australia where he

completed his PhD studying the effects of dietary salt intake on sweat composition and if you can't tell from that intro this podcast is all about the heat summer is here the heat is here and with it comes the need for athletes to adapt to that heat with interventions that you can kind of take into your training practice and also things that you can do from a nutrition perspective so have some fun buckle up for this conversation it was a fun one and i guarantee you you will leave the conversation with a little bit more knowledge about how to tackle the heat and also some really novel things that might alert that might actually emerge in the upcoming tokyo 2021 olympics it's weird to actually say that 2021 because it's an odd number and not an even number but in any case without any further ado here's my conversation with sports scientist alan mccubbin i wanted to start out a little bit by discussing this paper that came out in january of this year that you were the lead author on and uh it's a it's a position statement for nutrition for exercise and hot environments and i remember when it when it came out um the kind of the first thing that came to mind is like all this stuff is getting ready for tokyo yeah and there there are a few other uh

position types of stands that were coming out from various different uh entities and i know the training center here in colorado springs was kind of ramping up their you know final protocols for their athletes across the board and now that now that the summer games have been kind of delayed to 2021 i've been reaching out to people in the sports science industry just to just to say okay you put all these things in place early on you like gathered all the information okay this is what we're going to do with this position paper kind of referencing a wide variety of sports not just endurance sports which we're primarily going to talk about but it references a wide variety of sports like how do you view it now is it i mean it's obviously all still valid but yeah is it going to be something where you have to revisit like next january um maybe but probably not um i think these things are usually a long time coming uh whether it's a position statement or you know research you know the the turnaround time for academic research is fairly slow just because of the nature of you know getting ethics approvals designing studies getting funding doing it analyzing it and then the peer review process so you know it's not like these studies get you know we go oh today let's do a study and you know three months from now it's out and published um you know that position stand was probably almost an exception to that we sort of said yeah let's do it in july last year and then in january it was there in the journal and that's pretty unusual but obviously it's a review paper it's not you know we didn't do a study or anything for that um but i think you know in terms of um

of tokyo you know countries have been planning for this for well pretty much since it was announced that tokyo would host it um you know it's been years of planning that go into these sort of things um for pretty much every country and um and obviously from the the academic side of things people start to get interested in this and then you see as you said you know reviews come out from different organizations uh like i know i'm an author on another one that we did was specific to gastrointestinal issues uh in another journal temperature um that was again specifically looking towards tokyo um but obviously you know exercise in the heat isn't limited to just you know an olympic games every however many years a hot games comes around it's it's relevant to anyone in who exercises in the heat at at any time um you know some of the guys who contributed to that uh paper ollie jay for example he's a thermal physiologist here in in sydney um you know he does a lot of work with the australian tennis open which is obviously every single january um and they get you know really hot temperatures um you know over 100 fahrenheit you know over 40 degrees celsius um pretty much every year and so he's been doing a lot of work there in terms of trying to understand what's safe and what's not for players and um you know for example with the the main courts when to close the roof for the outdoor courts when to leave them open all that kind of thing so yeah now there's a lot of work that that goes into that side of things

and you know tokyo was kind of made it topical i suppose in terms of publishing work but you know that works really ongoing well and and more recently it kind of started with doha because doha was super hot and then tokyo especially for the marathon and the race walking events it looked like it was going to be like a repeat of doha and then all of a sudden they retracted and they ended up moving the venue which was really interesting to see play out because i mean you saw you saw it very uh very vividly where the athletes that felt that they could create a competitive advantage in the heat were just they were like hey listen we can handle this yeah and like protesting to to a certain extent yeah absolutely i always when when you go back and you look at you know some of the events in doha it was it was stunning to me the difference in the way that some of those athletes approached those events like some of them seemed to be like really dialed they had super good you know cooling strategies they had they had some sort of heat acclimation protocol kind of leading up uh leading up into the event and then other athletes like you'd watch them warm up and do things and they're like man you're doing the exact opposite of what you should be doing and i've always wondered like at that at that level like why does that even exist because there is all this research out there that's been there for decades i totally agree um and it's funny you say that because um you know one of my colleagues

steph who i work with at the university at monash um she works with one of the the marathon athletes from australia who went to doha and we were chatting to him about it afterwards and he he was saying exactly the same thing he saw about four or five other countries uh plus the australians um you know doing pre-cooling strategies and all that kind of thing getting ready and then he looked over and there was you know runners from some of the african countries warming up in track suits and full length you know tops before the race and he's sort of like you know what's going on here and you know he said that those particular countries didn't do particularly well on the day or the night as it was but um yeah no you totally totally correct about that and i think some of it is that there's all this research out there but it it's that translation of that research and how that gets to the athlete in terms of you know the practitioners that are involved in supporting them whether it's coaches whether it's exercise scientists physiologists nutritionists dietitians all these sorts of people and you know obviously some countries have got a lot more support in that area than others yeah you know the relevant point to the audience that um that'll be listening to this podcast and ultramarathon running will know about the bad water ultramarathon which is it's probably one of the best use cases in the entire world for everything related to heat stress the acclimation strategy the during competition cooling strategies the hydration strategies the nutrition strategies and the heat like the whole thing it's just a good it's just a really good case study because the environment

is so extreme and at the same time unlike a lot of other ultramarathon events um you can have access to your crew the entire way and so you can implement strategies there that you you know kind of otherwise wouldn't wouldn't be able to implement but still even then you know i've been going out to that race for i don't know 12 or 14 years now the athletes didn't always do the like the best things to get ready for it and i think we'll talk about some of that with relevance to this this paper here and some of it is just a little bit of you know the nature of ultramarathon training and running where it tends to be uh the the protocols tend to be like communally passed down from person to person to person versus research base but some of it is just every sport well it's true that's true i mean history right i mean yeah there's a culture of it absolutely absolutely some of it has to do with that and some of it just has to do with the evolution of things so we'll probably uh get into that into that for sure but i always like bringing up bad water because it's a special group of special group of people there which i i've done bad water so i can consider myself in that special group um but let's bring it back to this paper really quick um what what are like the like the big nuggets like the big rocks of information that you are trying to communicate to practitioners and athletes out in the field that they need to take into consideration for training and competing in the heat yeah uh well first thing i'd say with that paper is it's an open access paper so you know unlike a lot of academic

research where it's behind a paywall and you have to be you know a university staff member to access it anyone literally anyone can download this paper for free um so you know certainly encourage people to do that and it's not a particularly technical read either um you know there's a little bit in there but it's it's not too bad compared to a lot of academic papers so people are interested you know feel free to to go to the journal and get that but in terms of um yeah the the main sort of points from that that paper i guess that the main things is firstly in terms of trying to define what is a high environment um you know people say well you know at what temperature do we need to be concerned about all of this stuff and and the key take home from that paper is that you can't just put a single number on it um there's so many different variables that go into what makes uh a particular environment stressful from a heat perspective uh and that depends on you know the the exercise intensity that you're going at and that will depend on you know the if you're doing a hundred miler versus you know a half marathon for example obviously the intensity is completely different so the amount of heat energy that your body's producing per minute or per hour is is quite different as well um there's obviously the the climate itself and and yes temperature is part of that but it's only one part of that picture there's you know radiant heat there's wind speed there's you know humidity so all of those factors sort of come into play as well um there's things like clothing and equipment so you know like a multi-stage race where it's self-sufficient you got to carry

everything on your back uh you know you got to be water bottles strapped to your chest um obviously you know the ability to lose heat to the environment is is a bit compromised in that kind of scenario so that's going to make things a little bit more challenging as well um compared to you know a single stage race where you know it's fully supported and you can just pretty much wear the same thing you would to to do a training run if you wanted to so yeah all of these factors sort of come into play and so you know in the paper we make the point that you can't just say this is the cutoff beyond this you need to start doing all of these strategies and below that they're not relevant because there's so much um so many different factors that influence it i think the second point is in terms of how to prepare assuming that you know or expect that it's going to be a hot environment and what are we going to do about that um the biggest thing is actually not nutrition at all it's heat acclimation or acclimatization so getting your body adapted to hot environment before you go out there and do it um and you know depending on where you live in the world and where you're going to be training and racing um that can be a real challenge for some people and for some people it's just you know doing your normal training and that's all you need to do so uh you know if you have someone coming from you know winter down here for example and then traveling to you know north north america or europe to then you know compete in a hot environment that becomes really problematic

potentially as well yeah and you do need to sort of put those heat acclimation or acclimatization strategies into place so let's let's start there and talk about those um i mentioned earlier the bad water ultramarathon is something that's kind of revered and this is my you know kind of first coaching exposure to a lot of the heat acclimation and acclimatization types of protocols and the one thing that struck me when i first started getting into this about 15 years ago was that everybody seemed to have their own you know flavor of acclimation protocol some people used an overdress scenario other people like to use a passive sauna exposure other people like to use an active sauna exposure where somehow they you know cajoled their gym owner to be able to roll the treadmill into the sauna and somehow jerry-rigged the electricity that's needed to go to it and things like that and run and do jumping jacks and things like that and there's you know 100 different iterations and combinations not only of how to create the heat itself but also the intensity that they're trying to exercise at or having or having passive exposure the temperature the length the duration the durations of the exposure like all those things it struck me as there just was no real consistency to it um you know 15 or 18 years ago but that slowly started to condense down just in in my observation with seeing athletes that have to

prepared for that have to prepare for the heat and i think a big reason that that started to pare down is because is because we just know a little bit better about what what types of strategies are more efficacious than others and what types of strategies impact training more than others so why don't we kind of start there and let's run through maybe like the heavy hitters of the acclimation and acclimatization protocols that we can use for the heat and what some of the potential drawbacks might be of each of those yeah yeah so you're right and i think it's sort of converged on kind of that you know some people go for that passive approach some people go for the the active approach um i think in terms of trying to get those adaptations happening in the body what we're looking at is trying to get that core temperature up um to probably about you know 38 and a half to 39 ish um and for a sustained period of time you know at least an hour probably 90 minutes um per day consecutive days um for that full adaptation you're looking at probably 10 to 14 days to get all of those physiological adaptations because some of them happen quite early on in the acclimation process some of them take a bit longer to to occur so um i guess that's one of the things is that there is a sort of a duration component to that as well um and so i guess in terms of you know different strategies that people have had over the years whether they've worked or whether they haven't worked has probably depended on whether they've actually got that body

temperature up to that level and being able to sustain that for that period of time to have that level of exposure um per day um in terms of passive versus active i think that's still you know reasonably debated in the scientific literature i mean you know acclimation's not my area of expertise but um from what i see there's there's still not a an absolute consensus on that in terms of this is the way it should be done um i know you know with test events for tokyo last year you know different people went in with different strategies and i know a lot of people went in um with passive strategies uh and actually didn't feel that it worked very well for them uh and they think in hindsight that they'll probably go for an active strategy next time well the compromise has always been when you're using so first off let's kind of paint the picture of what a passive strategy versus an active strategy would be so passive strategy would be you're either going into a sauna or you're going into a hot water immersion bath and you're just sitting there nothing nothing's going on so the environment's heating you up right right the environment is reach is is what's responsible for reaching that critical temperature that you mentioned earlier of which and then the the adaptations can kind of emanate from there an active strategy would be using a combination of exercise and the environment in order to achieve that same type of thermal stress to which then the uh to which then the adaptations can occur and kind of the the from so i'm on the practitioner level right not on the

research level and i know you blend both of those the the teeter-totter that i've always viewed this on is the the passive strategies generally impact training less and so if you have if you have an athlete that you need to make a lot of you still need to make a lot of progress on the training front passive strategies tend to be able to blend those two worlds a lot better of where you can still have the athlete train hard and then the the the acclimation strategy doesn't it still impacts your training don't get me wrong but just not as much yes the active strategies because you're compiling stress on stress you're compliant you're compiling the training stress with thermal stress that tends to impact training negatively more and so you have to take more more training off of the table is that the way that a lot of the is that is that the way that you're kind of viewing the passive versus the active strategies as well yeah and i guess with the with the active strategy obviously to get your body temperature up to a certain level you got to do one of two things you've either got to get the environment hotter and hotter to do less work or you've got to do more work because the environment's not quite as hot um so you know the hotter you make the environment the less work you're going to have to do in that training to achieve that body temperature um but you know oftentimes there's only so much you can heat a room or whatever it is that your environment that you're exercising in so that's not always possible and so as you said you know you need to increase the exercise intensity to be able to

do that but then when you're doing that in the heat there's you know the element of that in terms of fatigue and being able to cope with you know whatever training load and is that sort of fitting with ideally what you want in terms of your training schedule at that point in time the other thing that's um i think getting a bit more traction at the moment is kind of a an active passive protocol so people doing an exercise you know a training session and then going into the sauna immediately after the training session to try and you know so the training session uh wouldn't necessarily be done in a hot environment it might be but it's going to get the body temperature up just because of the fact that you're exercising and then you're going to extend the period of time they're exposed to heat by then going immediately into the sauna afterwards and that's that's the protocol that personally i lean on the most um and that a lot of our coaches lean on the most is where we have an athlete they go out and they do a normal endurance session you know one to two hours something like that it's in a normal environment they don't have to over contrive you know anything and then they get within you know 10 or 15 minutes of finishing that session right into a sauna sauna exposure for 30 to 40 minutes they don't need to do it for as long uh as you're mentioning earlier because their core temperature is already uh elevated from the uh kind of from the exercise and i've always felt that that blends the best of all of those worlds in terms of not being able to compromise the training and then also minimizing the effect the negative effect that the heat exposure actually has to

have so you interrupt training as little as possible the downside to that especially when the competition is in really hot environments and this is probably what's uh related to uh some of the athletes that that had this feedback during the test events that um that you mentioned is that there's still a kinesthetic learning that goes on when you're exercising and you're working out hard and you're competing in a hot environment you can make all the physiological adaptations that you want to but the athlete still has to learn like learn and like kinesthetically feel out what that hot and what that hot environment is and we see that a lot going back to bad water right where a lot of the athletes they try to use and i laugh because it's just it's just a hilarious situation to me they use all of these completely over contrived mechanisms of heat acclimations where they're running in a sauna in a rain suit you know i mean like they're just compiling like for like you know if one strategy is good all three at the same time is the best but protein isn't it exactly yeah we that's another rabbit hole that we can go down but but but part of me appreciates that because they're trying to do whatever they can to experience the environment they might not be doing that in that vein they might think that they're getting the physiological adaptation but really i think the biggest thing that's going on is is their body is getting some even though the environment isn't completely compatible because all the humidity but they're they're getting some semblance of how it actually feels to exercise when your core

temperature is that high or when the environment is that hot totally agree and particularly for for ultra endurance exercise you know we can talk about all the physiology we want and the physiological limits on performance but when you're doing a hundred miler there's so much of it is psychological and that ability to tolerate discomfort and if you don't know what that discomfort feels like and then you experience it you're probably not going to tolerate it too well yeah i mean this is a this i like the way that we're approaching this it's kind of both from the egghead side as i affectionately refer to a lot of the physiologists out there but also the practitioner and the athlete side where you've got to realize that it's not a when we're doing these things it's not strictly limited to the physiological variables that we can manipulate there's still other aspects that we need to take into consideration when we're considering like training protocols and acclimation protocols and things like that yep totally cool okay so we got we got the goofy bad water people out of the way which which i always really appreciate so that's what we can do beforehand is acclimate right do something to acclimate seems like this active passive strategy from a bang for buck perspective is what's starting to emerge as the go-to with a lot of athletes but at the same time i think we'd be remiss not to mention that there still needs to be some sort of training and or test competitions in that type of environment just for the athlete learning what it's like in in those types of conditions yep

so now let's move to during the dirt like what what you can do during training and during hot weather competitions to essentially stay cool once again these kind of run the gamut and i also want to talk about some of the more like emerging and novel strategies that we're likely to see in tokyo 2021 it's so weird to say that because it's not an even number it's gonna screw everyone's calendars up no i don't so anyway let's get let's get back to the strategy so what what what are the big what are the big during activity and during uh race strategies that athletes can use yeah so i mean i guess there's there's a few things obviously uh the main mechanism we have to to cool ourselves down during exercise is going to be through sweat loss and evaporation of sweat so i think that's the important word there is evaporation you can have all the sweat you want sitting on your skin surface but if it's not evaporating it's not cooling you down and that's really an issue when you get into very humid environments that you know you have all this sweat pouring out onto your skin but because the environment is so humid you don't evaporate nearly as much and so you don't get the same cooling benefit um whereas the flip side to that if it's a very dry environment and particularly if it's very windy that helps evaporate that sweat off a lot more and so you get a far far more cooling effect and i think everyone kind of just knows that from experience and common sense really um so i guess from that perspective obviously there's a

hydration angle to that or aspect to that in terms of you know trying to replace that fluid loss um i guess there's a couple of angles that you can kind of attack this from one is that you know you're losing all this fluid to keep you cool so we need to replace that fluid how much is that how do we best do that etc um the other aspect is you know the the theory that oh well you know if i hydrate better i can keep a lower body temperature and that certainly does seem to be uh the case to some extent although i would say that the difference in body temperature is not that great we're talking you know less than half a degree difference generally unless someone's you know really severely dehydrated but they've probably got bigger issues to worry about then um you know performance at that point in time so uh from that perspective i i sort of look at hydration through that lens of of not necessarily it's a cooling mechanism but it's it's just trying to keep keep the system working properly by replacing you know essentially what you've lost from a fluid perspective and then i guess in terms of the other strategies is you know what are the other things you can do to cool your body down while you're exercising um you know 10 or 15 years ago certainly when i did all my training you know all the the sports nutritionists and dieticians used to laugh and go you wouldn't throw water over your head because you know if you're not drinking it then it's a waste of water but i mean we know now just from thermal physiology that actually pouring water over yourself is basically free sweat um and then that that will evaporate off your body and create a cooling effect so actually there is a

a benefit to doing that so you know obviously there's that strategy uh and then there's other mechanisms of cooling in terms of um you know the temperature of of what you're putting in as well um you know putting in ice or something you know close to to freezing is going to have you know more in to some degree an impact compared to um you know room or air temperature drinks which you know again using the bad water example is going to be pretty warm yeah and there it actually there's been some aspects of that that are debatable because i know for a brief period of time one of the big things that emerged uh predominantly in professional cycling but you also saw it in triathlon as well to a certain extent was doing a cold slushy drink you know so literally a a sports nutrition slurpee if you want to think about it like that you're just taking your regular sports hydration products and you're running it through ice in a blender um but it turns out that that actually might that a strategy like that might actually be too cold and somewhat counterproductive even though it could create a heat heat sink in the body yeah i think um where the research has sort of come to that is suggesting that the heat sink effect is maybe not as great as we originally thought um and it's fairly temporary um if you think particularly for an ultra uh you know the period of time you're producing energy versus the the small heat sink effect that you're going to

get um and the other the other factor there is that it may actually have an effect in reducing sweat rate which means that you know it may temporarily have a tiny little cooling effect but if it reduces sweat rate then you don't cool as much from sweat evaporation and then that's probably not a desirable sort of compensatory behavior so yeah i think that the slushies probably still have a role in the the shorter really high intensity events where you're not going to get a huge fluid loss where it's short and sharp and also in those events where evaporation of sweat is not being that effective so very humid environments for example um that might be not a bad strategy but i think for um when it's relatively dry heat when there's wind um there's plenty of you know sweat evaporation uh it may be questionable how much effect it's going to have and particularly for ultra stuff um you know it's kind of a drop in the ocean i suppose to have a slushy compared to the amount of total body heat you're going to generate over 5 10 15 20 hours of of running yep so ice water ice fluid would be productive in terms of cooling your body down but when you get it down to that slushy slurpy type of consistency that's where we need to it's not that it would be bad it's just not as effective right or it or it reduces the body's ability to sweat yeah to a small extent and i don't think anyone sort of really pulled that apart over a longer duration of exercise and said you know which is the the worst of those sort of two um effects

um but i think you know thinking more real world and putting that into a practical context how practical is it to get a slushy yet you know the 70 mile mark of 100 mile race or something right that um and down it and the other thing i guess thing to consider with that is you know there's there's a perceptual benefit possibly of having very cold whether it's ice or you know slushy or whether it's very cold water um it just makes you feel better so that's you know a good thing um but the other aspect to that is you know with the slushy that might be too cold you know you end up getting an ice cream headache um or it just stops you drinking as much um which you know in some scenarios may not be a problem in some it might be yeah and i think one of the emerging strategies that we will see in tokyo is the use of menthol um which i've always when this started to emerge i found this actually quite interesting because it takes advantage of this perception that you are actually cooler but that and that's worth something absolutely 100 like that perception is is worth performance and we see a lot of other areas in performance where your perception of something being better is what is what is going to create the effect but this is a really clear area where you're literally tricking the body into thinking it's cooler it's not actually reducing the thermal stress correct so where so what's what are the types of situations because this is what's going to come out i'm trying to like future proof this

podcast a little bit because what's going to happen is is like these athletes are going to compete in these hot weather environments and then menthol is going to be the rage and then the everyday athlete is going to try to use it in some use case that they they're all well the olympic athletes are using it i'm going to use it in my blah blah blah but that might not always that might not be a good use case for that particular athlete if they have to actually reduce their body temperature like if they have to use a strategy that literally needs to make them physiologically cooler and so i'm trying to like weed through that on the on the forefront of this so that once all this stuff starts to hit mainstream media we're like no no no no no we've always realized that this is a trick it's not like you know it's not doing anything physiologically to make the athlete cooler am i understanding that correctly that that's the that that's the strategy going on yeah absolutely so um menthol sort of activates receptors whether that's in the skin or in the the mouth and the gastrointestinal tract that give you that sensation of coolness but you're exactly right it doesn't actually cool the body down um and so you know there's a a potential benefit there in terms of you know tricking your brain into thinking you're cooler so you you know you push yourself a little bit harder but the downside to that is by pushing yourself harder you're pushing your body temperature higher uh and you know there is potentially you're pushing it dangerously higher uh to the point where you start to get exertional heat illness um and that all the you know consequences that that go along with that uh and that may be

different in in elite athletes versus recreational athletes as well um we know from some work when the the road cycling world championships were in qatar a few years ago that some of those guys are able to push their their core body temperature up to 41 and a half degrees um in the time trial now most people would be in a hospital bed if they were got to 41 and a half degrees but um it seems that these guys you know through repetition and training are able to to tolerate that you know better than you know your average joe off the street and so it may be the case with menthol as well that um it could do more harm than good in some people where yeah they end up pushing themselves harder because their brain's telling them they're not that hot um but in fact they then push themselves to be too hot for the for the for the audience uh members that are listening right now that might be a little bit uninformed about this novel strategy because it really hasn't been that widespread yet i mean what we're literally talking about is taking a cough drop for lack of a better word a halls which would be here in the u.s what is a fisherman's friend in in australia would be uh the brand okay yeah and and literally consuming it in in an effort to trick your body that it is that it feels cooler than it actually is outside i mean that's the extent of the strategy yes exactly right yep yeah so really simple not very complicated but all it is is it's a it's a it's i keep using the word trick but i mean in all essence that's what it is it's a trick your body thinks it's cooler than it actually is yeah and therefore

you can run a little bit harder cycle a little bit harder and things like that because the impact of how you are perceiving the environment isn't as isn't as great yeah i mean i guess coming back again to the sort of the practicalities of this a bit like the slushies you know from an ultra perspective that effects can be fairly short-lived like you you know pop a fisherman's friend in your mouth that effect might last five minutes maybe 10 something like that and then it's worn off so you know unless you're going to be popping one of those every 10 or 15 minutes for 20 hours you're not going to have that effect ongoing um ultra runners will do that you tell them that ultra runners will do that man you know it um i i guess the other thing to consider with with ultra running in particular is that because of the the exercise intensity like the relative exercise intensity is a bit lower um you know you're not running at marathon pace or half marathon pace so theoretically your body temperature is not as high um most of the time you know there'll be exceptions you know things like bad water and so on but um and so you know reducing the perception may not be as dangerous actually during that kind of scenario because you're less likely to push yourself up to that you know 39 and a half 40 degree kind of mark um because you're probably sitting at you know low 38s most of the time anyway um as opposed to you know something like half marathon where you're probably sitting closer to that 39 39 and a half and you're going to push yourself over you're over 40 by doing that

um but again you know how much advantage you get from that i mean that's the hardest thing in ultra uh is really any performance related strategy in in ultra endurance sports is it's just so difficult to study because you can't get people into a lab and go right just run 100 miles for me on a treadmill and we'll we'll do it as a time trial and you have to to run it as fast as you can like no one's going to do that yeah and so hard to find research subjects to do that exactly so that there is literally no studies that that do that and so you know most of the research that we have is extrapolated from usually studies of two to three hours of exercise and then we sort of say okay well it works for three hours of exercise so it'll probably work for 10 plus um you know what we're doing a study at the moment in the lab which is five hours of running and and that's like i can't think of many studies that have actually done longer than that in running like there's sort of you know walking protocols that have gone up to seven hours and you know obviously case studies at races but i can't think of any other lab study that's ever gone you know even beyond three or four hours let alone um you know what you would do in an actual race 100 let's dive into that study that you're doing in your lab and i have a little bit of familiarity with this just being kind of close to the space and i think this might help us unwind the the next topic i want to talk about which is the role of sodium in ultra marathon and ultra endurance events which i know is really kind of really in your wheelhouse so what why don't you

go first off just go explain like what you're trying to do in the lab and then if you can maybe tease out some of the little uh some of the results or some of the nuggets that you've learned so so far uh we can use that as a as a launch point to this next section yeah so i did my PhD looking at sodium um finished a bit over 12 months ago now um and what we were doing in in the PhD was actually looking at the effect of um how much sodium you consume in your day-to-day diet and how that affects how much you then lose in your sweat during exercise um and there'd been some research on that going back as far as world war ii but it was you know pretty extreme examples you know going on severe sodium restrictions and that kind of thing so we we sort of looked at it more through a a real world lens and sort of saying okay well if people load up on sodium before an event what does that do to their sweat sodium losses during that event um so we looked at like a three-day protocol um and thinking particularly that you know a lot of people go out and do you know commercial sweat testing and they get their result and you know however many millimoles per liter or millimoles per hour however you want to look at it um and then they go oh geez that's high i need to load up on sodium before my race so they go and do that but is that actually increasing their sodium concentration in the race and kind of you know cancelling out the the benefit of the the loading up uh and we found in that that yes uh you you do increase your your sweat sodium concentration by increasing the sodium in your diet

but over three days uh even if you effectively double your sodium intake from a kind of a normal intake you're only looking at a change of you know 10 to 15 percent in terms of sweat sodium concentration so that's probably not that extreme uh yes you know if you continue that on for a longer period of time it will probably continue to go up and you know the older studies of you know soldiers during world war ii would suggest that um but you know that's that's probably not realistic anyway and i guess the other thing that we we found from that was that you know if you do try to load up on sodium it's to a large extent fairly futile because 95 plus percent of that extra sodium you eat in that period just gets paid straight back out again you know your kidneys do a good job of keeping things in balance you know in a pretty short time scale um so that's kind of the stuff that we had done in the past but what we wanted to do this time around is look at okay well you know you do a sweat test and you get your result whatever it is um what does that actually mean you know if you go and um into a long duration exercise bout and you replace all of that sodium what does it actually do compared to taking absolutely nothing and so that's what we're doing at the moment we're doing a five hour study so they're running for five hours in 30 degrees celsius um on the treadmill so it's a it's a pretty sort of long and boring exercise bout but they get to watch movies and listen to podcasts and things like that while they're running so uh we try to try to uh keep them entertained so they don't don't

refuse to come back for the second one um and then we basically give them the salting capsules so we um we sweat test them on a previous visit we work out what their sweat sodium loss is and then we give them capsules to replace that exact amount so we individualize the the sodium replacement um to each individual and as far as i can tell no one has ever done that in an academic study um you know there's plenty of studies of sodium replacement looking at various parameters but they've always just given an arbitrary amount uh rather than personalize the sodium replacement to the individual and we thought that was really important because you know a lot of people are going out there and doing sweat testing um and it's being marketed on you know this need to personalize sodium replacement but it's literally never been studied before so um that that's sort of what we what we're doing um so yeah we're halfway through that study we we hope to finish off the data collection last year but we had a bunch of people you know one broke a leg in training um no at work sorry broke his leg at work one one rolled an ankle in training one changed jobs one moved into state and you know we went from having almost all our entire numbers that we needed to only having about half so we thought oh well that's fine we'll come back in 2020 and finish it and then certain global pandemic hit and then so yeah we were meant to start that again in in sort of early may and we're still waiting um to to restart that so whether we get get it finished this year or we're

going to have to go into another year we're not really sure yet so it's uh it's a bit of a long slow painful process at this stage a bit frustrating but you know that happens so let me try it let me try to encapsulate that a little bit um so what you did with the subjects from the onset is you had them do a sweat sodium test so you're testing the concentration of sweat or sorry the concentration of sodium in their sweat yeah were you also determining what their sweat rate was going to be in the environment so therefore you had a number of milligrams of sodium per hour that they were going to need to replace and that's what you were doing yep now how did you control for the fluid part of it were you also having them consume the requisite amount of fluid that they were losing or were they were they just drinking water ad libitum in the sweat test or the five hours the five hours oh so in the five hours uh we're doing ad libitum fluid intake because one of the things that we want to look at was when they take the sodium does that make them drink more yep because that's the and that's what i kind of wanted to get at because that's the knock right now with consuming salt tablets is that it causes you it and that that's the i'm using knock in quotation marks for the people that you know for since we have a failure of audio on this podcast right now um the the kind of the um uh one of the contentions with

using sodium tablets actually out in the field is that because it's such a highly concentrated bolus of sodium that you're consuming all at the same time it's therefore going to force you to drink more than you normally would which dilutes the sodium even further and kind of perpetuates whatever problem you might have going on in the first place so you're having them taking in the what would be the quote-unquote correct amount of sodium in terms of sodium per hour but then you were having them drink however they felt is there since this since the study might not come out for another two years based on what you just described with the pandemic is there anything like from the early findings that you can like kind of like tea like tease out to us yeah well i mean we're still blinded so we don't know which which one is which but what i can tell you is that they're not over drinking okay on either either trial so we don't know which one's placebo which one's salt um but we can tell you that you know in neither case are they over drinking at this stage um and so that's one of the things that has come out um based on a couple of case studies from western states i think where people ended up in hospital with hypernatremia uh and then people went back and tried to put the puzzle together of what happened and they took you know salt capsules or tablets or whatever it was in fairly large quantity uh and then drank a lot a lot of fluid and so the the conclusion and and again it's only two case studies as far as i can tell it's not a study of multiple participants it's literally

two people and um pitch piecing together the story from a hospital bed um after they they ended up there is that you know if you consume too much sodium that makes you excessively thirsty so you drink too much fluid and then you end up fluid overloaded with hypernatremia um certainly in our five-hour protocol where we're feeding them sodium at literally 100 of their previously calculated losses we're not seeing that um now maybe that happens if you go too crazy with the salt capsules and you end up replacing you know double what you're losing maybe i don't know um but certainly i don't think anyone would ever advocate for that so i'm not sure that that's a really i mean it's a warning not to do it but i don't think that's something that we need to really debate scientifically because i don't think anyone's ever going to recommend you replace more sodium than what you lose during exercise right well and the other thing confounding it in the western states case study that you mentioned is just the environment and hot dry dusty environment over hours and hours and hours is going to completely screw your you know your thirst mechanism and your capability of of of being able to perceive how actually thirsty you are just because of the damage that's going on you're breathing in all this hot air the entire time and athletes that are out there thinking that they're thirsty a lot of times what's going on is literally they're you know they've got damage going on at the roof of their mouth and their throats and things like that just from choking on all the dust and in whatever else

is going on during the time so it's a it's it's hard to put the puzzle back together i guess to your earlier point is when you're looking at these like retrospective studies of okay these athletes ended up in the hospital how do they get up how do they end up in the hospital there's all these confounding variables for what happened over those hundred miles in this case that's hard to put the hard to put it back together totally agree and and you know if you ask someone after they've had an episode of hypodatremia and they're very unwell or how much sodium did you consume in a hundred mile race that was yesterday or you know a few hours ago you know i've finished a hundred mile race i couldn't probably tell you accurately what i'd consumed yeah i know and that's if i was well let alone if i'd ended up in hospital i know you you know i was uh uh i was a runner in the western states 100 in 2011 when uh one of the studies that they did out there uh was they took the they they took uh the runners after the race and the ones that were hyponatremic they put them into one of three categories they either rehydrated them orally they rehydrated rehydrated them through a standard iv or they rehydrated rehydrated them through a super salty bolus i think it was a three percent sodium bolus and i got i was slightly hypernatremic at the end i don't remember what my serum sodium was at the time but just barely just just barely under the threshold um and they randomized me into the uh into the super salty bolus and we had no idea what this protocol was at the time because it was it was fairly new you know

had been used in emergency medicine a little bit we were just kind of like trying it out in ultra saying so i had no idea what was going on i felt better instantly yeah i mean it was it was remarkable and now that is you know it's it's it's more the standard of care that you see at these ultra marathons at the at the end where people are in a high turn nitremic state they don't put them on a sailing bag anymore they just give them this bolus just to fix things as quickly as possible it's been really cool to see that research emerge yep so this is your world how do ultra runners get it right like because it's it's confounding right because you see the you see the recommendations on the back of the salt tablets take one or two of these per hour and then you go talk to somebody else they're like no you need to get your electrolytes from fluid and then you go to you know some of marty hoffman's research who is the who he's the former uh medical director or what's his aci you don't even you don't need exogenous sodium at all and so athletes are getting these recommendations like left right and center that are that are apparently on the opposite sides of the spectrum like how do they make sense of it and get it right yeah it's a really good question and it's probably to be honest the reason i got into this area in the first place because it's you know if you look through the the sports nutrition guidelines and you know this was going back you know five ten years now but you know you look through those guidelines and you you look at carbohydrate and there's you know some numbers in there you know this many grams per hour or you

know grams per kilo depending which guidelines you look at you know fluid there's some suggestions there and you know obviously these are still debated but there is something there you get to sodium and it just it's kind of this vague statement like oh if you lose a lot of sodium you probably should replace some doesn't say when when it's too much to be lost it doesn't say how much you should replace and that's not a criticism of the the authors of these statements it's that they've got nothing to go on there's no research out there to inform them on how to write that guideline properly and so for me it was like well there's perfect opportunity from a research perspective to to fill a gap and that's what i've sort of been trying to trying to work on and so yeah it's a little bit tricky and it's it's still a lot of it is sort of based on hypotheses at the moment and you know marty's recommendations are based on you know his observations at western states and case studies he's done there and um yeah so it's a really interesting one and as you said there's there's really conflicting advice and i think a lot of that is because there's an absence of guidelines so people kind of just fill the gap with whatever suits them um you know if you if you're in the business of selling electrolytes you're going to fill the gap with that message if you're in the in the game of preventing hyponatremia you fill the gap with that message um and that's pretty much sort of you know what's happened along the way i think um so yeah in terms of i guess where my thinking's at with that at the moment um well first of all you know sweat testing so trying to work out how much

sodium you're actually losing so obviously uh i think most people are kind of aware that you know the amount of sodium that you lose in your sweat you know in in milligrams per liter or millimoles per liter so the concentration of sodium in your sweat is massively variable between people so anything from as low as about 20 millimoles per liter up to as much as about 70 or 80 millimoles per liter and this is over the whole body if you take you put patches on to collect the sweat samples which is probably the most commonly used sweat testing method you may see much higher concentrations from the patch and that's because certain sites of the body will have different concentrations of sodium in sweat so you can't take you know off the forearm or the forehead or whatever and say that's what's happening over the whole body um thankfully there are equations that you can use to estimate whole body sodium concentration from an individual patch site so you use standardized ones and that's that's what we do um because you know a whole body sweat collection you're basically exercising in what's a giant plastic bag and then you've got to completely douse the person in either some sort of chemical or deionized water at the end of it so uh if you're doing this in a lab and you want to do it with running you pretty much have to short circuit your treadmill by dousing it in about 10 liters of water afterwards and so those studies are done on on you know pretty basic bike ergometers because you can do that and you can cover it in water and it doesn't yeah it doesn't break the thing um and so you never see you know these

kind of studies done in running so if you want to do running you're pretty much stuck on doing the the individual site collections um so yeah as i said anywhere between sort of 20 to 80 millimoles per liter is kind of the standard concentration range that we see and obviously that's you know a pretty big range uh and then if you look at the um the total amount of sodium people are losing as you said earlier you know you've got to then multiply that out by the sweat rate so then you measure the sweat rate and again that's highly variable um it's highly variable between people but it's also highly variable uh you know on any given day within the same person um so you know and and even in an event like an ultra you know you could start the race at six or seven o'clock in the morning and it might be you know not much above freezing and then you get to the middle of the day and it's 100 fahrenheit or you know 38 degrees celsius and so you know the sweat rate is going to change over the course of an event just because you know it's colder at the start of the day it's hot in the middle of the day and gets colder again and then you're running overnight or whatever it is um and so yeah you can do this testing in the lab or in a training session but yeah a one-off test is only going to tell you right what's specific to that condition that you did the testing at that time because you can acclimate after that after exactly right and that's the confounding thing yeah totally and it's going to completely change things again and yeah that's why i did the PhD was that if you then load up on sodium is that going to change it again and the answer is yes but not by that much um the suggestion is even like with the sweat sodium

concentration that that will probably vary up to 15 percent day to day even if everything is identical so if i do sweat test today yeah if i sweat test today and i come back in two days time no difference in heat acclimation do it at exactly the same pace in the same climate controlled chamber in a lab still get a variance of up to about 15 percent in sweat sodium concentration so i guess the the way i talk to athletes about it is okay well you you might have gone and done a test and it might have said 50 millimoles per liter or whatever it is and i kind of say well that's kind of a ballpark don't don't cling on to that number as that's my number that's my target that i have to hit because yeah it's more of a range and and so i'd say it's it's almost kind of qualitative in like i'm at the upper end or i'm kind of in the middle or i'm sort of down at the lower end as opposed to you know i'm a 45 or i'm a 50 guy um and sweat rate itself uh is is thought to you know vary up to you know five to ten percent day to day under almost identical conditions so yeah it's it's always going to be pretty sort of qualitative in nature and as we said you know the conditions on the day are going to going to change as well so you put all of that together um so someone goes out and does a sweat test you know you might be you know 500 milligrams per hour or whatever it is if you're working it out in milligrams per hour and then you you go ahead and um you know aim to replace

that during a race and you might do that with fluid with capsules with tablets you know whatever whatever floats your boat i suppose um i i guess one of the things here then to consider is that if you have locked in a milligram per hour amount of sodium but you're uh you know you're varying your fluid intake based on thirst based on gastrointestinal comfort based on you know availability of fluid all these sorts of things you know you're replacing 100 of your sodium but you may not be replacing 100 of your fluid so if you're replacing 100 of your sodium loss but only you know 60 or 70 of your fluid loss essentially you're proportionally over replacing sodium relative to water uh and so you know you're going to end up with hypernatribia uh the opposite of hypernatribia and um that will you know reduce your sweat rate um pull fluid from your cells to the into the bloodstream to try and dilute that out again and that's not a desirable outcome either i mean that's basically what happens with dehydration so um yeah i think sort of hypothetically where i'm getting to with this is that you know in the past people have sort of said you do your sweat test and you make your recommendations based on the milligram per hour value whatever that is um whereas i'm starting to lean towards thinking actually no we want to do it based on the millimole per litre value that the concentration in the sweat rather than the total amount

that we lose and therefore if we do that we can allow the sodium to to go up and down proportionally as the amount of fluid we drink goes up and down as well um so if we drink 70 of our fluid we replace 70 of our sodium if we drink 90 of our fluid we replace 90 of our sodium and that should keep things you know reasonably stable in terms of what's happening in the blood and that's the exact way that we do it with our athletes um when we come up with nutrition plans for our athletes we have three kind of critical components and i think the the the the the the the rates are the are how we're determining the how we're determining the rate is the critical piece of that so on calories we're just doing it on calories per hour per hour yeah right being the critical component of that fluid we're doing it in terms of fluid per hour 20 ounces per hour or whatever based on a sweat test not not the sweat test that you're talking about but go out and exercise yeah sweat rate go out and exercise for two hours in this environment we know what your sweat rate is for that for that environment at that particular point in time that's but that's the second piece the fluid and it's fluid per hour and the next piece is sodium per unit of fluid yes and once we get those three components then we can kind of toggle them up and down based on intensity and environment and things like that but the the the key point of the the key relative point in this discussion with the sodium is is

the sodium recommendations that we're making are in terms of amount of sodium per unit of fluid volume not in terms of per unit per unit time and to your point if you kind of slightly overshoot your amount of fluid you know it's not as big of a consequence because you're taking in the requisite sodium same thing on the other side if you're slightly dehydrated right you're slightly undershooting your um your amount of fluid intake because the sodium intake is paired with that you're not you're not compounding that error with additional sodium intake or less than sodium intake or anything like that now those three things are really easy to say but hard like hard to execute because of the dynamic nature of the environment that the athlete can be in totally and i think that also comes down to how you're going to consume your sodium during exercise um right you know it's easy to say okay well you know out we're targeting i don't know 50 millimole per liter let's say just as an example and so we might say well everything we you know it's one thing to say everything we drink should have 50 fold 50 millimoles per liter of sodium in it but that's not really practical because there's going to be times where you're just having plain water there's going to be times you know you're having other drinks and things like that um a few and and i guess different athletes have different preferences um and so you know you can kind of accommodate that depending on the event um but there is events where you know you're going to be given bottles of water you know self-sufficient events and things like that where you know you're

not going to have these perfectly made up electrolyte drinks to exactly the concentration you want you're either going to take what they give you or you're going to take water and that's pretty much all that's on offer um so in that case you've been going to get the sodium from somewhere else and i think you know as much as capsules have kind of been trashed in terms of you know causing excessive sodium consumption well it's only if you take too many capsules um you know if you have capsules that have got a sort of a slower release coating it's not going to dump all that sodium into your stomach in in one hit um and then you can basically say well you know for every bottle or however you want to call it unit of fluid that you drink take one capsule or two caps you know whatever it works out to be um and you can do it that way and certainly i've done that with quite a few athletes recently i feel like we're just in another one of these nutrition ebb and flows that always happens with nutrition supplements and things like that they get hot for a while and then for whatever reason it gets demonized for a while and then probably like four years from now you're going to come back on this podcast and it's rubbish sodium yeah sodium capsules are kind of it's going to either be worse or get better or whatever it's just going to kind of like go down the toilet live on live on the podcast or something yeah it's it's it's it's great i mean i've been coaching for long enough that i've seen a few different few different cycles of this so i just kind of laugh but i think the take home i always try to drive these conversations back to the practical recommendations that the athletes can take away i think in terms of sodium which we were just talking about we need to think about it in terms of

the amount of sodium per unit of fluid volume that we're taking in and sodium from all sources as you mentioned yes taking a capsule and even sports nutrition products like gels and chewables they're going to have uh they're going to have sodium in it as well as well as the sports nutrition products the drinks and things like that which we typically think of as being the primary vehicles for uh for for sodium delivery yeah and i think you know in that setting we're not aiming for perfection we're not aiming for perfection because we know that the actual testing is is not perfect in the first place so we're working with the margin of error just in terms of the target we're aiming for and then you know on the day of the event you know you drop a gel or you don't quite get down all that drink that you intended or or whatever you're never going to get exactly the plan in terms of your sodium intake um it's it's just not going to happen so yeah um it's not what we're aiming for it's just trying to give us a ballpark to aim for you know if we're at the upper end the middle end the lower end something like that um and take it that way the other thing i was going to say i guess the the counter in this debate is you know there's that talk of oh you don't need sodium at all your body kind of just compensates for that there's talk of you know sodium stores and yes they do exist within our skin in particular and we know that that the skin is an area that actually buffers excess salt intake just in in anyone whether you you're an athlete or not um and then sort of releases that

back into the bloodstream um essentially as a sort of buffering mechanism to a high salt meal and then also you know gives the kidneys sort of a slow release of that sodium to get rid of it through the urine so it's not trying to dump all that sodium in in one hit um and so there's there's been a lot of talk about oh well you know you don't need to consume sodium during exercise because you know we've got this sodium store and we're just going to release it to prevent us getting hyponatremia and it's it's an interesting hypothesis but i don't think anyone's ever studied it so i think it still remains a theory it's it's certainly uh for all the talk about it i don't think anyone's ever demonstrated that it actually happens not not because it doesn't but because no one's ever done that study so again part of this five-hour thing that we're doing at the moment is trying to look for evidence of that do you anticipate having anybody actually being hyponatremic at the end of those five hours uh no i mean it's possible it is possible um i mean i guess we have a little thing called research ethics that we have to worry about um which means that we we do weigh people at the end of every hour of exercise so if we notice they're substantially gaining weight um we you know we take action around that so we we try to prevent that but i guess you know if they're consistently at the end of each hour starting to creep up the weight um then you know that's probably telling us that they're going to be at high risk so so you mentioned that there's this huge range of sweat sodium concentration that people can have

and um like anything else there's there's a bell curve associated with that and what started to emerge and i think you've probably noticed this as well in australia but in the us although we have slightly different you know sports nutrition manufacturers they tend to follow each other for the most part is a lot of the really high uh quality uh drink manufacturers they're trying to kind of hit the bell curve and that's anywhere from 400 to 600 milligrams of sodium per liter of fluid but we know that some athletes are not going to need that much and other athletes are going to need even more even more than that i mean over over a gram a thousand milligrams uh per liter outside of getting a sodium concentration test and and just as a just to kind of tease a future podcast i'm going to have uh andy blow come on from uh precision hydration they do a lot of this and a lot of these personalized hydration recommend recommendations to to to try to drill into that and that's going to come out maybe three or four weeks after this podcast comes out for the listeners out there but but in any case how can athletes outside of getting an official you know sweat test done on them figure out if they are on the lower end or the higher end of the range and i'm going to bring out you know one of the cheeky ultra

marathon myths of the salty sweater where you just have your training partners out there that they come back and they're just like caked and you know excess you know sodium all kind of all over their clothes and all over their hat and things like that but is there like a practical right is there like a practical way of drilling that down outside of going and getting a sweat sodium test not really i got nothing that's what you're saying that's the last piece of uh that's the last piece of work left over from my PhD which i was actually analyzing last night is trying to look at the differences between people rather than within the same person and trying to work out are there factors that can predict what the sweat sodium concentration will be um we were trying to look at particularly the influence of sodium intake again a salty sweaters just people who eat too much salt in their day-to-day diet um there may be an effect of that but i think it's pretty small um again you're looking at those within changes you know you have to make pretty dramatic shifts in sodium to start to see you know big you know any significant changes in in sodium concentration um the biggest predictor uh and this is going back again looking at sort of the the mechanistic lab studies the biggest predictor is the sweat rate itself so the higher the sweat rate generally speaking the higher the sodium concentration and so if you're looking at the differences between people some of that may be in terms of you know bigger bodies generating more body heat because they have to work harder to move at the same pace

um higher sweat rate therefore higher sodium concentration and the reason for that this is probably kind of getting into the weeds a little bit but um you know the way that sweat glands work is it produces the sweat in the the base of the sweat gland called the secretory coil and then it goes up towards the skin surface and as it goes up through the duct towards the the skin surface the um some of the sodium and the chloride gets absorbed back into the body and the thinking is that the fat you know the the higher the sweat rate the faster that sweat is moving through that duct and the less opportunity it is to to get it reabsorbed back into the body and so you end up with more coming out on the skin surface and hence you know higher um sweat sodium concentration and that relationship seems to be fairly linear so you know the higher the sweat rate the higher the sodium concentration over that kind of normal range of most people so if you know somebody who's just a heavy sweater in general that could that could be we're going to caveat this a lot that could be an indication that they also have a high sweat sodium concentration could be could be uh but yeah again you know we talked about heat acclimation earlier heat acclimation is going to significantly reduce your sweat sodium concentration it's going to do the opposite yeah exactly right so yeah it's it's one of those things that you know we can talk about am i the higher end the lower end i think to be honest unless you take a sample and look at it you're not really going to know for sure um and i guess the the

million dollar question which you know we're trying to look at at the moment is and you know hopefully future research is to look at does it actually matter so as you said you know most products trying to hit the the middle of the bell curve if you're at the ends of that curve and you still hit the bell curve instead how far away from that do you have to be before it actually matters and i don't think we really know the answer to that yet yeah maybe this is something we can kind of kick around a little bit because i've always taken the approach and i'm not going to profess that you know i have the right approach to this this is just based on deductive logic and logical extensions of the research as we were talking about earlier but if i have an athlete i would rather them be this is an ultra marathon situation i would rather them be slightly over what they need in terms of sodium per either per hour or per milliliter per unit of fluid volume as we were mentioning earlier i would rather them be slightly over than slightly under just because your body has a better way of adapting if it's slightly over and the negative consequences of that are not nearly as big as being slightly under and becoming hypernatremic over the course of 20 hours from an approach standpoint that's always the way that i've looked at it like when we're planning out nutrition where i'm like okay well you know if you're going to be taking in let's just say 600 milligrams of sodium per liter right if you're up at 700 or 800 i'm not going to

get too squeamish at that but if you're down at 400 or 200 over the course of many many hours 200 400 200 milligrams of sodium per liter if you're undershooting that over hours that's where we're going to have to start to put in corrective measurements that's always the way that i've like practically internalized it i don't know if you have any any thoughts on that one way or the other yeah it's it's a really tricky one to answer yeah as you said in the absence of of you know data to to look at it i mean i guess if you're over supplementing sodium relative to um your losses what's that going to do um well you know theoretically what it's going to do is inc will firstly increase the sodium concentration in your blood um and therefore the osmolality higher osmolality in the blood will draw fluid out of your body cells in towards the blood so you have a larger blood volume but less fluid within the cell itself um a higher osmolality if it's you know not not balanced will tend to reduce your sweat weight so that might be a downside to it in terms of you know body temperature regulation um for the same amount of total you know water in the body um and will tend to retain more fluid uh which again is that a good thing is it a bad thing it probably depends on the person and the situation um yeah i mean i think it's really hard to question to answer because we don't have data on that as i said you know this five-hour study we're doing at the moment is

literally the first one i can find in the literature that has actually sweat tested people and then replaced it according to what they lose everything else in the past has been just give them an arbitrary amount which is probably too much for some people and and not enough for others so that goes to your point of sort of hitting the bell curve um so yeah it's probably a difficult question to answer and uh but i think you know the consequences of not hitting the you know around about that target um theoretically should compound the longer the event goes but again you know our bodies are are pretty amazing things and they adapt to a lot and um you know who's to say we're not going to sort of adapt around that to a reasonable extent i guess it just depends on how much yeah and i've always considered the how much like plus or minus 15 percent like i don't really all pun intended i don't really sweat it if an athlete kind of comes back and says i was under my target by 15 or over 15 here like i don't like i said i don't really bat an eyelash one way or the other because the body's going to compensate and the measurements aren't really that precise yeah well that's plus minus 15 anyway yeah easily yeah easily um but um but anything anything above that like i'm looking for that out like the outside of it like if you're taking in 100 milligrams of sodium per liter of fluid or 150 milligrams of sodium per liter of fluid over hours and hours and hours and hours that would be like a critical error or if you're taking in like

two grams of sodium which we've seen athletes do that at races because you know once again ultra marathon psychology is is if one is good two is better three is best and five is you know the best ever ever ever or that tends to get out of control what's that or the counterculture people who say you know if one is better than that i'm doing zero minus more that's right yeah um yeah i mean there's plenty of um of papers looking at ultra races where people take no sodium at all and never develop hyponatremia um so there is that argument um i guess what you probably see in those people though is they end up with a lower blood volume because you know to balance out the sodium um plasma sodium concentration the osmolality that's kind of what has to happen um so you end up with less total water in your body and less blood volume um obviously if you know blood volume gets too low that's obviously a major issue but generally speaking once blood volume drops or plasma volume drops more than about 10 your brain kicks into gear in terms of making you more thirsty and then taking on board more fluid as well um but again if that's just water do you then you know dump some some stored sodium out of your your skin we don't really know because no one's studied it but it seems plausible um and i guess that the other thing is you know to have that lower body water that lower blood volume what are the

consequences of that for ultra both health and performance and i think that's something that we still don't really know 100 for sure because it's not really again as i said you really can't study performance over that kind of distance all as we can do is observe what happens to people in the real world and then try and make the best you know educated guesses about it yeah we're always extrapolating things right yeah yeah exactly and so you know people make the argument all the fastest guys do this so that must be the best thing and yeah you know the the appeal to authority that happens a lot of time and in sport in general but ultra running is a i think a uh uh a hyper example of this just kind of gets nauseating sometimes the i saw so and so do this so now i'm gonna do it it's like well sometimes they're just a really good athlete yes yeah exactly right um i want i want to kind of leave with a strategy that is starting to become uh that's starting to emerge more and more and one that's actually been around for quite a while i mean i first ran into this strategy in the in the early 2000s where it was really pulled from a lot of like mechanic mechanistic types of studies at the time and that's this concept of hyper hydrating immediately before an event so the morning of an event or maybe even the day before where you're using and what's what's commercially what's starting to emerge just because it's more it's easier and it's more practical is a hyper hydration solution a

super salty solution that would contain like one and a half or maybe even two you know two grant two two grams for a 16 ounce serving of fluid in the effort of like pre-hydrating yourself before an event in a hot weather environment and i can tell i can i'll i'll give like a practical a practical anecdote when we started implementing these strategies with our athletes particularly at some of our hot weather camps that we were doing is that it was literally a game changer like we had athletes that were going from completely melting down in the heat day after day during these training camps to absolutely thriving and at the time at the time we for at the at the very first time we started implementing these um these types of hyper hydration strategies there wasn't a lot of research on it it was very much like mechanistic type of data but we saw that the athletes would actually improve out in the field and now they're starting to there has been started to emerge like at least some data in terms of what is actually going on with those athletes so why don't we review like what we know about those strategies and if they could be solid ones and what we have to watch out for with those because it can be a dangerous one with certain certain types of athletes yeah so um i think firstly part of the reason why there was sort of a gap in in research is that the main ingredient that was used or the main product that was used for hyper hydration was glycerol and glycerol became banned by the world anti-doping

organization off the top of my head about 2010 or 11 um because it was thought it could be used to mask banned substances um and then that's since been reviewed and and they've realized i'm not sure if it's because testing's improved or because they realize actually it's not doing that but it's no longer banned and so um you know research kind of really paused on that because people were like well what's the point of researching this to try and help people win olympic gold medals if they can't take it anyway um so you know that's that's kind of resumed a little bit more recently um so glycerol is one of the ways to do it um sodium loading is the other one that's commonly used and basically to be to be clear to be clear before we go on somebody accuses me of of doping athletes or something like that the the salt the the the mechanism that we were using in our camps was the sodium version of this not the glycerol they're getting at the same answer they're trying to do the same thing yes but the vehicle that we were using for the hyper hydration uh in our setting was strictly the sodium one at no point was it the was it the glycerol one part of because the complications that you mentioned because it went from not being banned to being banned and then not being banned again do you remember when they took it off the banned list the most recent time i think yeah yeah super recent so anyway continue continue with your story i wanted to throw that caveat in there before somebody thought i was like yeah you know part of something nefarious going on um yeah no fair enough um yeah so i mean i guess the the concept behind both glycerol and sodium is is basically the same it's to try and increase the osmolality

in the blood and therefore retain more fluid so osmolality just to you know i've mentioned a couple of times already it's basically this concept of how many molecules of stuff is in a certain fluid so we talk about solute being the molecules and then the the fluid being you know water or you know whatever it is in this case it's the plasma in our in our blood or the serum um and so there's obviously different things that you can put into your body from um from ingesting it that will increase that osmolality you know sodium is probably the most common one um glucose actually has a has a minor role in that as well um although it's pretty tightly regulated so it's hard to really push that um and glycerol is is another one uh and so what happens is there's a couple of ways our body sort of regulates fluid in and out and you know how hydrated we are and when our kidneys kick into action and produce more urine or they conserve and produce less urine and um the main one or the most sensitive one of those is osmolality so when our body detects that osmolality is high um plasma or serum osmolality is high um we tend to retain fluid so we don't pee out as much and we tend to be more thirsty so we want to drink more and so if you can add more molecules of stuff into the blood you'll retain more fluid in there to try and balance that osmolality out because it wants to keep it within a pretty you know tight range

um and so if you load up with sodium or load up with glycerol and get that into the blood and then take a lot of water with it that water will be better retained and not peed out compared to if you just took the water without the sodium or without the glycerol so that's a basic concept you know behind how it works um so in terms of like sodium loading for example what you're trying to do i guess is drink a solution that has a sodium concentration that's as close to what's in the blood as possible because that's going to maximize the retention of that fluid um but it's a trade-off between you know maximizing the retention of the fluid and being able to actually stomach what you're drinking um and so you know most drinks that are sort of designed for this shoot a little bit below that um so it's you know the the body's sort of sodium concentration is usually 135 to about 145 millimoles per liter a lot of these solutions are sort of around the 130 ish mark uh and i think that's simply because um well one they don't want to overdo it but two you know the higher in salt it goes the less palatable it becomes and you don't want to have something that you can then vomit up or just people just refuse to drink it um so yeah then that's that's sort of what happens with sodium in terms of the the period you load uh it has to be a relatively short-term period like two to three hours before exercise um because but you know with with sodium for example when we saw this in our three-day one is you know you can load for three days but you're going to pee out most of that excess

sodium and not retain it over that period anyway because your kidneys are going to after a few hours just adjust and bring things back to where they were beforehand um so there's no point doing this you know days beforehand it's it's literally the the few hours before you before you start um and so you're trying to yeah increase that um that blood volume and therefore the total amount of water in your body the theory being that if i'm going to be sweating a lot during exercise and i'm in a situation where it's not practical to replace all of that fluid uh i can try and maintain hydration status better than if i'd not been hyper hydrated all that you know that's kind of the theory behind it yeah and the the protocol i i don't mind peeling the curtain back on this protocol because this podcast has no sponsors or anything like that and part of the reason i don't have sponsors so i can mention these things and then trash other things that i think are rubbish but uh the protocol that we we use is we use a commercial product like scratch hyperhydration or osmo has a hyperhydration uh solution we administer to the athlete athlete would drink you know 500 milliliters of it during breakfast hour and a half later or something like that we'd go out and do the exercise session and it i i don't i don't i don't use these words lightly because i don't like to like oversell protocols that we use but for the athletes that were really struggling in the heat and primarily the ones that couldn't keep up with the with the uh fluid consumption that they needed in hot weather environments it it it made a big it made a big difference and there's there are not a lot of

protocols out there that i will say that about whether it's an acclimation protocol or a nutrition protocol or whatever but for whatever reason this one for a particular subset of athletes that have issues hydrating it you know it it has a lot of efficacy to it just in what we what we see in the field how do they find the taste by the way because i'm aware of the scratch one but i haven't tried it it's uh you gotta kind of bite the bull a little bit you know it's not the it's not the most but athletes are willing to do that i mean they try they try to flavor profile it we've used a few of them the scratch and the osmo ones yeah it's it's really not that bad um to to to be honest with you it's better cold yep and those are like trial and error things right you put a little bit ice on top of it it's a little bit better cold and then if you just you know take a you know take a deep breath and you know chug it all in the in in one spot we are a little bit cautious from a practical standpoint especially when we're working with um like non-elite athletes when we have athletes that are just normal people at our camps and things like that if any of them are hypertensive just inducing that big you know sodium load all at once we sometimes will like cut the dose in half or or something like that but you know all all being said i know people like knock the taste and things like that athlete before the before their training you know it's not that big of a deal now during i would not use it as a as an intervention because of a whole host of negatives that could actually come about

there's no reason why you would so is glycerol going to make a comeback on this olympic cycle uh i think it's quite possible yeah i think um you know it provides uh probably tastes i haven't used a lot myself but i think it probably tastes a bit better than some of the sodium loading protocols that people have used uh it kind of has a very sweet taste to it rather than being incredibly salty um whether that makes it hard to stomach the volume um yeah i haven't haven't worked with a lot of athletes yet that have sort of done a lot of glycerol loading it was one thing that um like i do a bit of work with triathlon australia and it was one thing that we were looking at doing um in terms of prep for tokyo and then when everything happened we kind of you know we were literally a couple of weeks out from starting to play around with it when this this you know the whole pandemic thing sort of happened and races got cancelled left right and center so we had no races to sort of use as as guinea pigs for it so um yeah i haven't i haven't done a lot of glycerol loading myself uh you know with athletes that i've worked with yet but um it's something that we've got on our radar yeah i mean now that it's off the band list i think you're going to see a lot of athletes start to kind of reintroduce it uh as a protocol or start to tinker around with it um so to what so i think suffice to say i think 2022 is going to be the year of menthol sports nutrition products in the year of glycerol sports nutrition products we'll probably see that emerge exactly exactly we always see this every olympic cycle like something comes out like the last summer olympics after that was like the

year of cupping because of all the cupping marks on this particularly the swimmers like michael phelps and things like that this is going to be no different where we start to see some of these things start to emerge yeah exactly um all right alan well i appreciate you coming on this has been great man um really fun conversation one that's extremely topical here in the u.s this uh podcast will come out uh in july and you know it's going to heat up bad water is going to be one of the it's looking like at least fingers crossed it's going to be one of the few events mass participation events that actually happen here in the u.s their race director has been pretty upfront about we're going to try to make this happen kind of come hell or high water and all the athletes are getting in their sauna protocol right now is uh as we speak so it's going to be topical uh certainly here in the u.s when it comes out i think it'll be topical again once the uh once the olympics come around and like i said i just really appreciate your time uh before we break here why don't you tell people where they can kind of find more about you and what you do either on the academic side or in the in the commercial space yeah so um my academic work is at monash university which is in melbourne here in australia um so if you go to twitter for example we have the monash exercise nutrition and exercise sorry the monash nutrition and exercise clinic is the um the full um the full name on twitter so if you search that you'll find it and the same on on facebook and that's probably the the main places where you'll sort of find out what

we're doing so um any new studies we publish will all sort of come out through there um when we're recruiting people for studies um obviously you probably have to be based in melbourne for most of our studies although we occasionally have questionnaire based ones and i did one of those in my PhD which had people from north america the uk hong kong everywhere um so yeah all of those sort of new studies that we're recruiting for come out through those channels as well um you know in addition to that yeah you're right i do some private practice work as well so my business is called next level nutrition there is an american next level nutrition which is completely different um so mine is next level nutrition.com.au and the twitter handle is uh next lvl n-u-t uh sort of an abbreviation of that so um that's probably the place to find me i'm not as active on twitter as i would could or should be but um yeah i try to try to keep a bit of a presence on there in terms of stuff i'm doing but also you know sharing other stuff that's happening that i think is interesting and of use to people and and then the final thing um uh it's not always cycling specific but i do some writing for cycling tips as well so um a lot of the topics on there while it's you know it's obviously a cycling website a lot of the stuff on there is equally applicable to really any endurance sports so some of that stuff is relevant as well yep and that's how i initially got uh uh became familiar with you as your work on cycling tips you do a really good job with that um appreciate all your time all the links to everything

that alan just mentioned will be in the show notes and alan thanks again we will uh cross paths at some point once australia lets people in and out of the country but uh until until then we'll have to keep having virtual conferences like this no worries thanks very much all right yeah man and there you have it folks thank you guys and gals for listening to another episode of the KoopCast hope this episode kept you cool or in the future it will help to keep you cool hope you learned something from it if you have not had the opportunity go on over to itunes and subscribe to this podcast so you get new ones whenever they are dropped i've been doing these once a week every week even through the pandemic all in an effort to keep you all informed subscription is the best way to make sure that they land on whatever podcasting platform you prefer also if you have not taken the time to do so go ahead and give a rating or a review on itunes it helps the podcast out a lot this podcast is ad free and it's always going to be ad free and i do that in an effort to give everybody listening the honest to god truth anytime you're listening to this podcast you can be assured that there is nothing influencing it in the way of advertisements or sponsorships so thank you to the listeners appreciate everybody listening today and we will see you out on the trails