Altitude and Performance with Robert Mazzeo, PhD | Koopcast Episode 65

trail and ultra runners what is going on what's happening welcome to another episode of the KoopCast as always i'm your host coach Jason Koop and this episode of the podcast is going to be all about altitude how altitude affects the body and how to train for races at altitude one of the most common questions i get on a weekly basis is how someone living at sea level can train for an event at altitude i get it not everybody has the luxury to live and train in the mountains and there's a big intimidation factor for these athletes so on the podcast today to help solve this riddle i have robert mazio PhD robert is one of the most respected physiologists in the world today and has conducted some of the most important research in high altitude physiology that coaches and physiologists alike can lean on to inform training for athletes professor mazio also has an absolutely incredible free online course that anyone can attend and i actually didn't know this before we got on the podcast so i actually went through some of the sections and i was blown away at the content i'm going to take the entire course once i can get around to it for any coaches or athletes who do not have a traditional exercise science background and you want to better inform your training i would highly encourage you to check this content out and the link is in

the show notes and we begin our conversation a little bit about discussing this particular endeavor here we go here's my conversation with robert mazio all about altitude i've got a massive open online course on coursera on the science of exercise and that was definitely watered down for the layperson and and to date there's over 700 000 visitors on it it's a free course wow that's incredible will you send me the link to that afterwards because i'll put it in the show notes yeah sure i'll send you the link to that absolutely and anybody can join anyone can do it and it's free so uh so there's it's it's uh separated in the four modules the first module is on exercise energetic so we talk about you know carbohydrate fat protein metabolism atp the second uh modules on physiological systems cardiovascular system respiratory system endocrine system immune system the third module is on basically performance we talk about what causes fatigue muscle soreness performance enhancing drugs and the fourth module is on health we talk about exercise on lowering risk factors for heart disease diabetes certain types of cancers obesity uh alzheimer's all that and is it a is it like a self-paced curriculum yes yes it is wow i might send my coaches to that now that i know about it seriously like i've gotten a lot of coaches uh physical

therapists personal trainers that take this course but i was surprised that uh people are taking it from over 500 different countries in places where i didn't even think they had the internet like libya and yeah i'm sure as you can imagine when we hire or when we hire new coaches they come from a variety of different backgrounds right i mean it's it's an interdisciplinary type of profession and sometimes they have proper exercise physiology backgrounds and sometimes they don't and sometimes there's kind of like and i came into coaching this way as well where it was kind of a hodgepodge of things in between and we're always searching for ways to get everybody to start with the same playbook right once we bring them in and then we put our own continuing education kind of on top of that so this is this probably be a pretty good resource you know this would be a perfect resource for that yeah all right i appreciate it um but we're gonna talk about altitude yes we are and i know and i know you love this i got the chance to run around my house this morning and look at pike's peak which you're quite familiar with i've been up there many times i've driven up the pike's peak road i can't tell you how many times have you been up there since it's been paved uh i haven't been up there no not since not since the last part's been paved no it's um there so they're redoing the summit house right now um to the tune of i think it's a 50 million dollar project wow um all all funded by toll road money and by uh donations so no tax money going into it and it is a huge huge huge huge project and i think

that expanding or make giving a more permanent home to the lab that you worked out of is part is kind of part of that whole endeavor the uh you know the army owns the f it's the research facility up there yeah and uh they've conducted it you know every time we do a study up there as i told you we've done i've been a part of four studies at pike's peak we always give the army a piece of the action so that they can get some publications out of it well the military has always been quite good at producing research with arduous conditions albeit altitude or heat or sleep deprivation or things like that so altitude folds in right folds in really well there yeah our studies were funded by the department of defense you know because they were interested on how uh soldiers would perform at altitudes like in afghanistan yeah well we we owe a lot of what we know is you're aware uh we owe a lot of what we know about altitude research kind of to two really uh prominent figures the first one is being the u.s military who likes to study their soldiers in these adverse conditions but the second one is the mexico city olympics right we can trace all of this altitude research back to the 1968 mexico city olympics and at that time competing in that type of that type of environment that type of altitude was kind of a relatively it was an unknown quantity at that time the athletes and the coaches and the physiologists that were going into that situation they really kind of didn't know what to expect and they had a couple

of lead up like the pan-american games and things like that were uh lead ups in into that event and they started getting all these anecdotal reports back from the athletes that the that the distance events in particular are much harder in the sprints and the jumps everybody was doing a whole lot better exactly yeah so most of the x-phys textbooks these days compare the uh 68 uh mexico city olympics with the 64 tokyo olympics when they look at performance times in short events versus more long distance events and so so with this kind of like long history there's been there is continually a number of athletes all across the world and in particular with with in the ultra marathon discipline that are always looking to gain an edge when they go up to altitude and ultra marathon racing has this really unique proposition where some of the races are at extreme altitudes and they're very attractive to that group to that audience because of the altitude yeah in part you've got races like hard rock which has an average elevation of 11 000 feet you've got leadville which starts in leadville colorado which is at 10 200 feet and on and on and on and on and we're faced with this kind of like similar prospect every year with athletes where they're coming from sea level usually it's the midwest or the east coast and they complain about the client the lack of climbing that they have and they're going to these altitude environments and they want to be proficient right at at exercising at performing at that

at that at those altitudes we're going to get to the answer or hopefully close to some answers to that question a little bit later but i think like to start out with we need to go over like fundamentally what happens acutely and chronically when an athlete goes up to an altitude we'll use a moderate altitude anywhere between 5 000 and 8 000 feet for our north american audience we'll we'll work in the u.s system so can you give us a broad overview first of what happens when athletes go to those altitudes yeah so the first thing you know just to set the background for your listeners is i want to talk about the principle of homeostasis uh and so basically what that principle is it's the uh desire of the body to tightly regulate a number of key physiologic and biochemical factors in the internal milieu of the cells and tissues to optimize their functioning and survival so the body likes to tightly regulate a bunch of key factors to make sure the cells are under their optimal conditions and they function uh properly and so these are things like for example body temperature so as you know if you get hot you start sweating that's the reaction to try to cool your body down um if you're exercising your blood glucose levels can drop so we need to regulate blood glucose by mobilizing glucose from the liver um oxygen is another factor so anytime there's a disruption in homeostasis uh the body has to kick in

its regulatory mechanisms to try to offset and adjust for these disruptions now both exercise and ascent to altitude are clear stressors that disrupt homeostasis even at sea level and acute bad of exercise and a strenuous exercise is probably the most significant disruptor to homeostasis short of death i mean you do an intense exercise your blood ph can change your temperatures changing your oxygen levels and demand for oxygen is changing your body needs to regulate all these things and the way it regulates it it has these various sensors that help respond to this disruption in homeostasis the major ones are the central nervous system and specifically during exercise we're talking about the autonomic nervous system which consists of the sympathetic nervous system and the parasympathetic nervous system but what it does is when you start to exercise and your muscles start to use more oxygen to supply adenosine triphosphate for fuel uh you need to get more oxygen delivered to the exercising muscles and the way it does that is there's you know it turns on the cardiovascular system you increase your heart rate you increase your stroke volume that's all designed to increase your cardiac output and increase oxygen delivery to the muscles you increase your ventilation so your respiratory rate goes up to try to get more oxygen from the environmental air into your lungs to keep your hemoglobin saturated with oxygen blood flow to the exercising muscles uh increases the muscles vasodilate all that kind of uh adjustments to

disruption and homeostasis induced by exercise are regulated by both the central nervous system and key hormones you get a the catecholamines play a big role you will people talk about their adrenaline so the adrenal glands when the body gets stressed you see you see a response to your adrenal glands and it releases epinephrine or adrenaline and that helps with controlling the cardiovascular system the respiratory system blood flow to the exercising muscles that also is involved in fuel regulation so now you go to altitude and you have another stressor you have an environmental stressor exercise is a physical stressor you go to altitude now you have an environmental stressor and that's hypoxia so the basic uh physiology is here is you go to higher altitudes the barometric pressure goes down and as per Boyle's law when the pressure goes down the volume of a gas expands so the gas expands at higher altitudes that means there's less oxygen per liter of air at higher altitudes so the O2 density basically is going down and that of course is going to disrupt homeostasis and the body even at rest when you go from sea level to high altitude the body's going to have to make adjustments to that disruption in homeostasis because your arterial partial pressure of oxygen in your arterial network is going to be well below normal at sea level depending upon what altitudes you're at and then when you have exercise at altitude you have a combination of stressors that the body needs to

adjust to which it can acutely so when you exercise when you first arrive at a high altitude and then of course the body makes long-term adaptations so this is basically the underlying mechanism for the overload principle and training adaptations or even acclimatization if you go out and exercise five six days a week and you do that um for several months when you repeatedly stress the body it will make long-term adaptations these are the training adaptations for the cardiovascular system it's going to be an increase in stroke volume increase in my maximal cardiac output increase in your vo2 max your your the volume of oxygen at maximal exercise your body's going to make these training adaptations when you go to altitude you're going to have acute stressors and we can talk about what those responses are to the to the to the body and then if you stay at altitude you're going to start to acclimatize it's going to make these training adaptations so to speak that allow you to improve both oxygen delivery and utilization by muscles both at rest and during exercise so when you first go to altitude the problem clearly is hypoxia so a below normal level of oxygen in the environmental air and eventually that translates into a lower partial pressure of oxygen in the blood hemoglobin is less saturated less oxygen getting to tissues i love the fact that you're equating

hypoxia hypoxia or altitude exposure to exercise in terms of the stress that it puts on the body and the subsequent adaptations that the body tries to make in order to overcome that stress yes and it's it's it's a very good analogy because again the underlying theme for both of them is disruption and homeostasis that the body needs to make an adjustment to and again if it's subjected this for a long period of time uh we're going to see adaptations taking place in the body both as a result of exercise training at sea level or acclimatization at altitude so when you go ahead oh no what i was going to say is is my my point with that is is that a lot of times we look at and we being the coaching community athletic community we look at altitude interventions through the lens of how do i get exposure to this altitude but if you realize that exercise exposure is making a lot of the same adaptations that you would want if you're going to a high altitude type of environment you can say okay well and we're going to kind of come back to this later i'm sure you can say well training might be your first intervention to overcome whatever's going on at altitude and then you might look at an altitude a specific type of altitude intervention after that yeah that's a that's a good way to look at it so when you first go to altitude you know this hypoxia this low partial pressure of oxygen in the blood is sensed by the body

so one of the immediate adjustments it makes is you increase both your resting and submaximal heart rate that's designed to increase your cardiac output and improve oxygen delivery to all tissues including skeletal muscle so you get an increase in heart rate both at rest and during exercise you also get an increase in ventilation your respiratory rate goes up that's designed to try to get more oxygen into the lungs and to keep the hemoglobin as highly saturated as is possible at that partial pressure of oxygen now not surprisingly because of the hypoxia your vo2 max your maximal oxygen consumption decreases at altitude and that decrease is dependent upon what altitude you're at another thing that happens at altitude is for a given submaximal exercise you have a greater production of lactate lactic acid and lactate and that has implications to uh with regard to acid-based status and ensuing fatigue at altitude as well so that there don't appear to be any key biochemical adjustments that occur with acute exposure to high altitude such as increasing red blood cell number increasing mitochondrial oxidative capacity or even increasing capillary density those all happen long term but the the immediate responses are to try to improve oxygen delivery as best you can in response to this disruption and homeostasis caused by this hypoxia and one of the interesting features of that is that

everybody will recognize it's harder for me to exercise at altitude if we just normalize the situation we have somebody running eight minute pace at sea level we all of a sudden teleport them to 14 000 feet on the top of pike's peak and we have them run eight minute pace up there that's going to be a really hard adjustment yet the actual amount of oxygen that they're consuming in both of those situations is going to be remarkably similar it just feels harder because their vo2 max has been reduced by so much and therefore the percentage of vo2 max that they're actually working out at or exercising at is a greater percentage of vo2 max at the out in the altitude condition as as compared to the sea level condition yeah no that's an excellent point it's it comes back to uh comparing an absolute workload at sea level and altitude to the relative workload and that's very it's a very important point because the higher the relative workload so if you're running at that eight minute pace at sea level let's say that you're working at 70 percent of your max vo2 and you know you're at some altitude where that same pace is going to require you to work closer to 90 percent that higher relative workload it's the same absolute workload but that higher relative workload creates even a bigger disruption on homeostasis the higher the relative workload the greater disruption in homeostasis and the greater the need for the body to make adaptations to compensate for that stress so that's an extremely important point the difference between the absolute and relative

workloads when you're talking about comparisons with sea level and altitude yeah and i also think understanding that has a little bit of influence on some of the interventions that you might actually introduce to the athlete like if you understand actually what's going on it's not actually an economy impairment it's a maximum it's a maximum aerobic output impairment essentially you can look at the you can look at kind of solving the problem differently which i think we'll get into in a little bit but before we get too far down the weeds with the actual answer which everybody wants everybody just wants the answer let's kind of keep going through this background right so we talked a little bit about acute responses what about the chronic adaptations somebody that's at altitude for two weeks three weeks four weeks what is going on there for the body to adjust yeah so you know the key one that everyone always points to as as a result of the hypoxia your kidneys start to release erythropoietin EPO which has also been used by athletes such as athletes in the tour de france to blood dope it's a it's a chemical way to blood dope as opposed to the autologous way of the classic blood doping when you re-infuse yourself with your own red blood cells so you get this erythropoietin response uh within 72 hours of arrival to altitude which can peak around two weeks dependent upon the altitude and the person as we'll discuss later there's people that get classified as

responders and those as non-responders that the altitude acclimatization process but the major adaptation there is to increase erythropoietin EPO and what it does is it stimulates the bone marrow to make more red blood cells so what you're doing is you're trying to increase your hemoglobin concentration which is the carrier of oxygen in the blood uh only about 1.5 percent of oxygen is physically diffused in the plasma the rest of it's carried in hemoglobin the other 98.5 percent so the more hemoglobin you have uh the more oxygen you have and you can carry so obviously increasing your red blood cell number is one way to increase your oxygen carrying capacity another thing that the body does is it you urinate more at altitude to try to decrease your plasma volume to concentrate the red blood cells you already do have and again that's another technique that the body uses to adapt to hypoxia to concentrate the red blood cells you already have and so both of those are designed to increase the oxygen carrying capacity of the blood so you can deliver more oxygen to the tissues but other long-term adaptations the body starts to excrete bicarbonate to get rid of the bicarbonate that helps with acid base balance so one of the problems is that that when you go to altitude as i said before your ventilation goes up you start breathing more to get more oxygen into the lungs and into your into

your uh red blood cells but you're not producing any more carbon dioxide if you're just sitting there at rest so your ventilation goes up you start lowering your co2 levels like if you were to sit there right now and hyperventilate your co2 levels would drop and your blood actually becomes more alkalinic that's one of the factors that can contribute to acute mountain sickness along with dehydration so one of the ways the body adapts is it gets rid of bicarbonate it's one of the uh chemicals that's involved in the buffering capacity to help you have this ventilatory adaptation to acclimatization another thing that happens at altitude is so we're talking about oxygen delivery we try to get more efficient at oxygen utilization so we do see an increase in capillary density in skeletal muscles so basically to increase local blood flow in the delivery of oxygen and again dependent upon the altitude we see an increase in mitochondrial concentration the actual organelle designed to utilize the oxygen that's going to produce the atp for muscle contraction so those are some long-term adaptations that you know that are attractive to athletes because if you can increase your mitochondrial oxidative capacity you can increase your oxygen delivery you can increase both your vot max and hopefully uh your performance there are so many threads that i want to pull on with that you pull you you pulled up five or six different adaptations all of which we could do a three-hour podcast on but one of the key ones that a lot of the listeners will be familiar with is this

concept of responders versus non-responders which has kind of gotten haphazardly thrown around in the lay literature that's my that's my opinion let me just state that from the onset that haphazard nature and my my experience with this is that these altitude interventions have gone from these especially in high performance scenarios have gone from nearly de facto meaning everybody did them in the 90s and the 2000s it was just something that happened everybody went to an altitude camp or is trying to get an altitude tent or something to now we look at it in a through a much more selective lens that is tailored around the situation and the athlete individually so not so much a responder versus a non-responder but what does the situation actually dictate will this athlete create the adaptations that we actually want i was wondering if maybe you could expand on this concept of responders versus non-responders or maybe people who respond individually to these types of exposures yeah so when it comes to altitude you know there there is a tremendous amount of variability as to these adaptations that i just listed and there's been a number of explanations for it you know one is that the dose you know uh what altitude you're at is going to play a role the other one is how long you're at that altitude is going

to play a role another one is what's your fitness status before you go to the altitude acclimatization process you know people that lower fitness have a wider range for improvement that really high class elite athletes do and then of course there's always the genetic factor even at c level you take two people the same sex the same age the same vot max you give them the exact same training stimulus they're both we know they're both going to improve but one may improve more than the other so there's the uh genetic factor the individual variability principle basically is what's coming into play there and then of course for the athletes you know as you're talking about customizing it for an individual it it depends what their event is as well you know are they ultra marathon runners are they milers all these things come into play you know the early studies on the live high train low by ben levine we're done on people running uh relatively short races you know uh 3 000 5 000 meters so it all those factors come into play and that explains why there could be a wide variability in the response to altitude and altitude training yeah and the so first off there's a little bit of a personal connection there ben did some uh physiological testing on me when i was a teenager way way way back in the days it was right around the time when he was doing a lot of this a lot of this research um so i i don't i don't have through that and i've had many conversations about that early research with him

um the interesting thing with the altitude interventions though as it relates to to performance is that it's one of a handful of interventions where you can get a negative or a mal adaptation you can get a negative response or a mal adaptation which basically unwinds all of the hard work that the athlete has actually done and what we're starting to learn a little bit more about in terms of the individual response it's not that difficult to actually do you can put somebody in an altitude tent you can send them out to an altitude camp and they come back worse than they were when you sent them up there yeah that's absolutely right and there's a number of reasons for that so um on these pikes peak studies we had a nutritionist that was painfully making sure that these athletes i mean these subjects stayed in energy balance so one of the things that can happen is uh you lose your appetite when you go to altitude initially and that's there's a number of factors related to that including increased sympathetic nerve activity uh also you increase your resting metabolic rate so a lot of these studies done uh by folks in in copenhagen they reported when they did these altitude training studies that their uh subjects lost about five to ten pounds of muscle mass so they weren't staying in energy balance now the studies of pikes peak we had to be force fed these folks so that they stayed in energy balance and maintain their muscle mass so one you can lose your

muscle mass and that's obviously going to have a negative effect too as you well know you can't train at the same absolute intensity that you're going to compete at at sea level at altitude so you could have what they call and i do the quote air quotes the training effect because you're not training at the same absolute intensity at altitude because you know it's a higher relative workload and you can't sustain that for a prolonged period of time and thus the live high train low strategy comes about so let's get into those there have been any number of different altitude strategies and for those of you that aren't looking at the youtube video of this i am just laughing my face off right now because i'm trying to i'm going to try to recollect by just off of memory of how many different altitude interventions that i've seen over the years and they seem to get every single year more and more convoluted but yes one of the one of the reasons that they have become so convoluted is because of this detraining aspect because we know that we can't produce the same power we can't run at the same speed at altitude as we can at sea level and there's been this attempt to try to separate where you do your resting essentially and then where you do you're working you want to rest when it's high and then work when it's low not that that's the perfect answer but but that is the vein that has created all of these different permeations of live high train low live high train high use this intermittent hypoxic exposure and things

like that so with that as a little bit of a backdrop we've what's kind of come out of the woodworks are four different uh protocols essentially or four four different strategies that four four four strategies of which there are probably 10 different iterations of that i've seen coaches and practitioners it's about fair statement right yeah i think that's definitely a fair statement okay so the first one is a live high train high strategy you're going to go out to leadville colorado and train out on a leadville course if you're training for the leadville trail 100 second would be a live high train low strategy which is more classically adopted in like the olympic distance events so here in colorado springs they go out and they live at woodland park which is at like 8 300 feet and then they come down to colorado springs or sometimes even pueblo which is like an hour and a half drive which colorado springs is at 6 300 feet and then pueblo is at like 5 000 feet or something like that so they're training at a lower elevation as compared to where they're sleeping and the same strategy would be if you used a hypoxic tent then you have intermittent hypoxic training which is training super high using a mask so sometimes 15 000 feet sometimes 20 000 feet i've seen that protocol as well and the second and then the last one would be intermittent hypoxic exposure which is just passive exposure to an extremely high altitude for relatively short periods of time and then somehow that shock to the system provides the catalyst for all these adaptations that we were speaking about

earlier that's a mouthful so you're the expert here you get to pick on which one of these we go through first and how important or relevant it actually might be for athletes yeah so the first thing is are you taking part of any of these protocols for performance at altitude or are you trying to do for performance at sea level so the live high train low paradigm is designed to help your sea level performance it's not really going to help with your altitude performance well it is because you're going to in one respect because if you're living high you're going to have all those adaptations associated with high altitude uh but living high training high that's going to help if you're going to be performing at altitude uh that paradigm is is probably the best way to go for performance at altitude but it's not going to help you with sea level so um those are things that have to be kept in mind when you're talking about which paradigm is best suited for the athlete is it going to be performance at sea level or performance at altitude and then the intermittent hypoxia i just saw another study that came out just recently where they wanted to do the live high train low but then they wanted they added a little i for intermittent hypoxia training for about three hours three times a week so uh like you said they're coming out with all these different iterations of the original design that basically make you start

scratching your head but again getting back to your question for sea level performance i think it seems pretty evident that the live high train low if you happen to be a high responder is potentially the way to go to improve sea level performance if you're going to compete in the leadville 100 uh again living high training low will at least give you the basic acclimatization while you're at let's say altitude for 22 hours per day but you're probably better off training at the higher altitude if you're going to be competing at the higher altitude so your body gets adjusted to that type of physiological stress and in that case the penalty that you pay for not being able to exercise at sea level is negated by the competition environment right because the competition environment is at a higher altitude lower power output lower speeds anyway is that what you're saying essentially yes but you have to get used to that i think you need to adapt to that before the before the actual race and so let's put ourselves in the position of of a stereotypical athlete that i probably see 100 or 200 times a year we've been using leadville as an example so we're going to continue with that it's an athlete that's coming up to the leadville trail 100 that's from nebraska or from texas or from florida or some other you know uh some some other location where they don't have exposure to this altitude would an intervention where they lived high and train high and this is what a lot of them try

to do they go up to leadville they do a camp up there they might participate in you know some of the tune-up races that are in that location how would athletes go about being best served to take advantage of those types of opportunity and how can they avoid some of like the deleterious things that might happen because of that exposure yeah so for the folks that are at sea level um if if they're one of the things they can do is they can just come out to leadville like a week to 10 days ahead of time and and basically use it as a base camp type of scenario like mountaineers do before they go to try to summit everest uh if they're like in nebraska they don't have access to hypobaric chambers or wearing a mask with a reduced uh oxygen levels uh they really are going to be at a disadvantage unless they do come out early and try to acclimatize uh again it doesn't take oh you know you don't have to be here a month is what i'm saying a week ahead of time you start to see the changes in the acclimatization variables such as epo that i talked about earlier and so i think that's their best route to go you know geographically if they don't have access to uh high altitude where they can spend some time and acclimatize and train then they're and they don't have access to these hypobaric chambers and i think their best uh avenue to pursue is just coming out

early and try to acclimatize prior to the race huh so you brought up something that i love and i get a kick out of is for years we've heard this dogmatic point of view uh with athletes that are coming from sea level and they're going to an altitude a race at altitude that they need that they need to i'm emphasizing that word intentionally they need to get to the race within 24 hours of the race starting or three weeks before the race and i've always found this recommendation hilarious because anybody who's not an elite athlete has an extremely problematic time actually doing that they can't carve a month out of their life to go live in leadville colorado to in order to acclimatize but you you actually made this really uh interesting point where you said listen if you get there a week to 10 days you're probably going to be okay and that that speaks to what i want to get into now it's not a light switch that happens these are all biological adaptations that happen over time courses and they happen incrementally as well yes they happen gradually and again the extent to which they happen is going to be dependent upon the altitude and your genetic makeup what type of responder you are now is in the in the case of a camp is there such a thing as a repeated bout effect for altitude meaning you come up to altitude once for two weeks three weeks or whatever do you get

better or do you acclimatize quicker after subsequent bouts why during that two-week camp no afterwards so you go up to altitude for a couple weeks you come back down sea level the next time you go up is it a better experience is it the same is it harder easier well if you go up if the next time you go up is longer than three to four weeks after your initial time up at altitude it's going to be basically the same so what you're saying is is there has to be a shortened kind of compressed time frame between the first exposure and the second exposure to take advantage of the adaptations that you that you incurred during the first exposure that's exactly right and that's both only not only for red blood cells but also for the buffering capacity as well that's you see with acclimatization and so could you you could also say the same thing for a live high train low strategy where the competition is at sea level you want to time the the removal from the altitude exposure appropriately in that case as well oh yes that's very critical because if you come back uh and your events not for another month once you return to sea level you're going to start to lose those adaptations that you gained while you were living at high altitude okay so the the athletes that are training for a level trail 100 that are coming from florida have some sort of blueprint right if they can get up here and do two exposures that would be okay or if they could get up to leadville within a week or 10 days of the race that would be efficacious

as well let's talk a little bit about some of the ways that are more convoluted to to to accomplish the same uh accomplish the same thing we already mentioned the use of an altitude tent what are the what if any are the important differences in using an altitude tent either the type that you put over your bed or now that they actually have the types that'll actually fit over your head have you seen those right yeah they just fit over your head they're kind of crazy looking but they work um what are the important differences between that type of altitude exposure and a natural altitude exposure i.e. actually coming out to ludville or carl roll springs or pikes peak yeah so uh the most of the research seems to indicate that whether you have uh normal barric hypoxia what you're talking about is when people at sea level use these uh hyperbaric instruments to try to simulate high altitude or you actually have hypobaria out at high altitudes the adaptations appear to be the same but when it comes to those altitude tents i have to tell you i'm not a big fan for a number of reasons one is they're very expensive and two i've had a number of uh people complain and which is true that your sleep is very fragmented in those types of situations so that can affect your training as well having this disrupted and fragmented sleep and it's well known that even at altitude you know when you go to the actual altitude itself sleep is disrupted but it seems

to be to a greater extent in these you're not in your normal bed you're and you're sleeping in these tents and or you could be if you had the canopy to set up but still your your sleep is disrupted and fragmented and it could affect your training yeah i've always looked at that as a situation where you could get two up ten down right you can get a two percent improvement from the tent but you could easily get a ten uh ten percent regression in your fitness just by lack of sleep or they get hurt because they're not uh because they're not sleeping well or for whatever reason they require more macronutrients and you're not covering for that like it just becomes in my opinion problematic in a lot of cases yeah sleep disruption you know we can we could have a three-hour podcast on that unfortunately i have four sleep physiologists here at the university of colorado that i can consult with but uh that induces other chronic stressors that makes training more difficult as well so i i agree with you two two up ten down and again everyone's going to be different you can't say this this is going to work for everyone or this is going to be negative effect for everyone people just have to try it and find out to see what works and what doesn't work for them but the important thing is is if you're going to use a tent realize that there can be potential big downsides and your upside might be limited and so if you are compromising primarily sleep maybe it's not the best idea and your fitness is more important yeah and you obviously you know if you're going to spend the money you better hope it works

if you find out you're it's not working for you then i don't know what the return policy is on those people say that about coaching all the time you're spending money on a coach you better improve and i i absolutely agree with that statement okay so this leads us to what in my estimation is it it's kind of presented as the goldilocks solution to this and i say presented as very intentionally and deliberately and this is intermittent hypoxic exposure so you're supposed to be able to get you're supposed to be able to get all of the adaptations that we were just talking about increase in red blood cells increase in mitochondrial biogenesis and all those other things and none of the deleterious side effects your sleep isn't compromised you don't have to sleep in the tent you don't have to actually travel up to altitude and all those other things this is something that the listeners are going to be less familiar with so we're going to have to paint the kind of the general protocols first and then go through why or why not this might be a valid solution for athletes so so you take it over when we talk about intermittent hypoxic exposure what does that mean and can it actually be beneficial for endurance athletes yeah so what's going on here is people are just they're not training but they're being exposed intermittently uh it could be the three to four hours a day several times a week uh and they have to dial in at the correct altitude uh generally it's usually between 7 000 and 10 000 feet they're trying

to simulate and the idea here is that just by you're you're at home you're at sea level you're being exposed to this hypoxic uh environment and you're going to make these adaptations which we've already talked about before as far as you know increased red blood cell number mitochondrial biogenesis uh but you're not you're not training you're just being exposed to it it's a passive exposure you're sitting down you've got a mask on you're sitting down yeah you can be playing video games or whatever you want to do yeah uh if you look at the literature the literature is not too positive on the effectiveness of this on improving uh performance you know there's i'd say of the studies about 65 percent say that the intermittent hypoxic exposure is uh again if we're talking about trying to improve sea level performance is not the uh not the best way to go the results are equivocal for most of the studies showing that uh sometimes there's no change sometimes there's a little bit of change but it may not be worth the effort you're better off just training at sea level so again if you're just going on the current literature i'd have to say that the the intermittent hypoxic exposure is probably the least of the uh paradigms that are recommended today but yet a lot of athletes will do it based on this notion of there's no negative right at least from a training consequence yeah there's negative in

terms of time and cost and things like that but from a is it going to impact my training at least that's the thought there's no negative to which i still say you're still taking time and resources and maybe there's a recovery impact if you're just sitting there at 10 000 feet or whatever you have the thing set up maybe there's a recovery impact for that i mean i don't know if you have any thoughts along that aspect of there might be no negative associated with it yeah i don't think there's any really important significant negative consequences of the intermittent hypoxic exposure unless you have to happen to be extra sensitive to hypoxia which you shouldn't be doing this anyway um but you know there's lots of things out there that are considered ergogenic aids that don't have any negative impact you know you could take all these various supplements from beetroot or whatever and you know you're just wasting time and resources but i don't want to get into those right now yeah i'm gonna have a whole podcast on things that have no negative associated with them that you could waste time on no seriously i'm gonna have somebody on we're gonna go through the whole thing it might take it might be like three three hour specials or something like that by the time we go through the list list that we have is already several pages long let's let me just put it that way that's a good tease for everybody listening um okay so you you've been doing this i'm not trying to out your age robert but you've been doing this for a while you've been studying physiology at altitude for a longer than a lot of people have been running that are listening to this

to i'm sure that's the case yes i've been at cu for 35 years so let that just gives you a reference unbelievable and i always appreciate i always appreciate uh people who have been at this for a long time their perspective because they've seen the way that that philosophy and thought process and the research has changed over years what do you want to come out of this like what do you think the future holds for looking at this area of high altitude physiology and performance what are the things that we don't know that you want to know going forward yeah so originally i got into this because i was interested in uh some more serious consequences we've done studies on people that were subjected to high altitude pulmonary edema high altitude cerebral edema and so we were interested in the under underlying physiological mechanisms there but you know i've been in the field of exercise physiology for a long time so i've always uh usually used that in addition to the altitude as the stressors that i was talking about so basically you know we still have a lot to learn and if we're going to focus just specifically on performance and not just basic high altitude physiology adaptations um i think the the big question out there right now is the exposure to altitude we know that the increase in red blood cell number plays a role in improving performance especially when you go back down to sea level because we know

blood doping works we know epo injections work um but it seems that there are many other factors that we're not aware of that can contribute to the improvements in performance and the acclimatization process and this can range from exercise economy it can it could have to do with the buffering capacity which still is a little bit hazy um it could do with another adaptations with mitochondrial adaptations that occur free radical or oxidative stress so there's a number of other factors out there that we really don't know to what extent they contribute to the adaptation process both at altitude and to the potential improvements with performance as well and is your lab going to try to answer some of those questions coming up are you going to rely on the military here at pikes peak with a new facility that they're just building that we're talking about earlier well funny she should say that because next week i'm retiring oh so i'm so i've shut down my lab you know 35 years is long enough uh coop but are you gonna are you gonna hang on like uh like your colleague roger crom has and have like little you know little fingers in the pies of the cu physiology world come on now you know i might hang on like uh he has but it won't be in the area of altitude physiology because logistically it's not that uh feasible to to do unless you're actually going to these large studies at the summit of pike's peak yeah well i i do hope that

i do hope that that that the work up there does continue it's been uh it's been a really bright spot on the research because we've learned so much from it and i know something that's really near and dear to you to your heart congratulations on your retirement i did not know that before we got on the before we got on the horn today i'm kind of honored that this is like one of the last things that you're going to do before you sail off my swan song here i love it i love it i feel like you're going to sail off into the distance and go fly fishing at a high altitude high altitude lake or something like that for the rest of your life all right thank you for your time um i'm gonna put links in the show notes to all the research uh that you mentioned as well as uh the class that we're talking about before we got on the air today um i can't i can't tell you enough how much i appreciate people like you and your contributions to what we know about performance and altitude and exercise physiology so thank you for that globally and also thank you for coming on the podcast today well thanks coop i always enjoy talking about this as you well know and there you have it there you go appreciate the heck out of robert for coming on the podcast today that was really fun it is one of my favorite areas to discuss and i gotta be honest i am honored and humbled that we could get robert on the podcast today just before his retirement robert you leave behind an incredibly distinguished career and one that is filled with influence that we can draw upon specifically in altitude and with exercise physiology we as a collective community of athletes and coaches

cannot thank you enough for that hope the listeners hope you guys enjoyed this episode the links to robert's course are in the show notes appreciate the heck out of each and every one of you and as always we will see you out on the trails you