When to Switch from Running to Walking to Maximize Ultramarathon Performance with Jackson Brill | Koopcast Episode 108

trail and ultra runners what is going on what's happening welcome to another episode of the KoopCast as always i'm your humble host coach Jason Koop and on this episode of the podcast we have another repeat offender and that is jackson brill and we are going to talk about the exact same thing that we talked about during the first time i brought jackson on the podcast and that is when to run and when to walk and what catalyzes that transition and most importantly for all the athletes and all the coaches that are out there listening why it is important to train for both of these modalities very specifically and are they in fact different skills jackson recently presented his master's thesis to his graduate advisors at the university of colorado boulder as well as he gave that that same presentation to our entire coaching department and so i thought it was a good opportunity for us the listeners to take some information from jackson's research and from his presentations and see how we can practically apply it to athletes as they are training for ultra marathon events jackson is a heck of an athlete in his own right he's going to take the world by storm one day i have no doubt about it he is also wickedly smart and he just happens to have this fascination between running

and walking and steep mountainous events in order to maximize his own performance so you guys watch out for jackson in the future so there we go i'm going to get right out of the way here's my conversation with jackson brill before we get too much into it let's kind of set the table right because i want i want everybody to understand how like how your master's defense kind of came about because there's it's a little bit of a odd origin story with uh with you kind of re-analyzing data that you already had so why don't we just go through that first because i think it's just a cool it's a cool pivot to to set the table on this sure um so i uh originally started working in this lab uh as an undergraduate so this is the locomotion lab at the university of colorado in boulder uh so i did my undergraduate um degree program in uh integrative physiology you know worked in this lab um you know my last two years uh there and um we did a undergraduate thesis um that was kind of the original intent of collecting this data so um that undergraduate thesis was looking at preferred transition between walking and running on uphills and looking at a few different metrics to see if they could predict um or i think a better way to say would be trigger the preferred transition um and then the goal was you know so so then i ended up

doing um what was a one-year addition to that program to get my ms so um see you as a cool program where um if you're a good enough student you can kind of do a do a one-year add-on um and pick up another degree so i kind of got grandfathered into that program and uh prior to uh this little uh sickness that took over the world called coronavirus the goal was to do a uh entirely new project so um create an entirely new um study you know recollect data um you know read and and do the whole thing from scratch uh but um due to a lot of circumstances um one being covid uh we ended up just i ended up just finding myself in a position where the easiest and best thing to do was to um use the data i had already looked at and um ask a couple more questions with regards to it so um i i'm going to quickly talk about what the study that i wanted to do was because it's really cool we're going to have um people do time trials up green mountain in boulder so that's the mountain with all the flat irons on it and they were going to do three different time trials one time trial they're going to run the whole way another time trial they were going to walk the whole way and another time trial they could um use whichever gate you know they preferred go back and forth um and whatnot uh and then we were going to um you know have gps data um and have speed and kind of looking at uh you know the the

incline and then how that changed looking at the speed and how that changed uh we thought we were going to get some cool um findings with regards to you know prefer a transition and and alternating gates but actually in the field so looking at you know how might rocks and roots and you know just being on the side of a mountain instead of on a treadmill um change some of these things so uh it's still a good idea for a study um so uh if anybody out there wants to wants to do that uh talk to me i'm happy to uh happy to give some advice and um yeah kind of kind of walk through through that maybe in a little more detail but um yeah ran into some roadblocks with that uh it it snowed a lot earlier in the year than we anticipated um this would be fall 2020 and then um grad school is a lot of work uh even outside of the research so just was kind of finding myself a little stressed for time so the end of the day um made the decision to yeah just look at that um previous data that i collected as an undergrad i hope somebody does pick up that research because i was quite intrigued by it because anytime you do something in the field like that it's it makes it all the more kind of like real and and and as well as practical um so let's let's dive into let's let's dive into the paper first off i assume that at some point down the road we're going to see this pop up in an academic journal right you guys going to submit it that would be the goal yeah um our because our sample size was pretty low particularly um for kind of the questions we ended up asking for these master's projects right

the original goal of the study um was to ask entirely different questions we had some reasonably large p-values you know not a ton under 0.05 so we might run into roadblocks with reviewers who are still uh you know aggressively tied to that idea of p-values um and needing needing super low ones to to mean something so we'll do our best um there's kind of two different parts to the master's thesis is um i'm assuming we'll kind of get into so we're probably going to kind of split those up and try to um publish each of them uh as separate articles okay so for the listeners what i'll do is it's i'll put a link to it in the show notes but it's not going to obviously go to an academic journal it'll go to something on you know my google drive or something like that where they can download it and you can if you need to redact anything you can redact anything from it so i'll just i'll send you the compliance or whatever i'll send you the url for the like submitted version to see you um yeah that probably works better it's funny because when i emailed you i was like this is actually the final version and then like 20 minutes later i got an email from the grad school saying oh table three was a quarter inch over the margin on page 37 oh my god so i had to go back in do that um so yeah that that'll also be the true official version not the 99.8 finished version that you saw okay perfect all right that's the end of the housekeeping let's dig into this right off of the bat you made this statement in the slide deck that i'm actually looking at right now

humans prefer to walk at slow speeds and to run at fast speeds which is so brilliant and simplistic to start out with and what you're essentially exploring is is what triggers the walk to run and run to walk and what is slow i guess and what is fast right if they prefer to run at fast speeds and prefer to walk at slow speeds how can we essentially categorize them and figure out what is the trigger from one to one so to start out with what were essentially the like the questions that you were trying to answer when you were when you were digging into this problem right so because we collected um data for the preferred transition speed so that that speed that you know that's slower than that humans would choose to walk at faster than humans would choose to run at um we also we so because we kind of collected that speed for each subject collected on a variety of inclines we um have the you know some cardiometabolic data um and variables that we um collected for similar speeds and what that allowed us to do you know once we analyzed it is um give us some evidence for do some of these cardiorespiratory cardiometabolic um parameters do they serve as the trigger for preferred transition because like you said we're trying to ask why do we switch um at the speed that we do so the two um kind of variables in question that we looked at for my graduate work were minute ventilation

or breathing rate so the um units for that would be liters per minute or just the total volume of air um that you're breathing in you know over per time and the other um variable that we were looking at uh was the carbohydrate oxidation rate so uh i think it's it's easier to think of that if we first think of there's an overall um energetic rate there's an overall cost of you know performing exercise performing movement and then within that uh you know at least for um the exercise intensities we were looking at that's made up of the amount of that energy that's provided from carbohydrates and the amount that's provided from fat so kind of within that overall energetic cost we were then looking at um the rate of carbohydrate oxidation the percentage of that energetic cost being provided from carbs and um wanted to see if that could serve as a trigger as well okay so you're exploring this this notion of when what what is the trigger from running to walking and back sorry yeah walking to running and then back from running to walking i think it's so simple but i can't even get it straight and you're using the the bioenergetics to or you're exploring the bioenergetics and seeing if there is some relationship between a certain point of that bioenergetic spectrum and this and this transition describe first so everybody can kind of have this picture in their mind what the research design was like

like how many subjects did you have what did they actually go through and then we'll then use that to describe all of these other different kind of inflection points that may or may not dictate this run to walk and walk to run transition right so the um i guess yeah first just getting to the subjects they were all 10 male high caliber male trail and mountain runners because we're looking at um inclines as steep as 15 degrees um that just required a really high level of um of exercise ability so that's kind of why we limited it to just that pointy end of the fitness spectrum um as well as you know limiting it to just males um we didn't think we'd have enough um we didn't think we'd be able to recruit enough women to make it um you know to kind of get enough data on on that front and um yeah so for these subjects we first termed the preferred transition speed and the way we did that is basically had subjects start on a treadmill at a very slow speed so they were undoubtedly going to um want to walk at that speed and then we raised the speed of the treadmill slowly but surely until eventually the treadmill was going fast enough that then subjects were running and we recorded that speed at which um that switch occurred and then we and then we did the opposite so started the treadmill fast lowered the speed of the treadmill until eventually subjects were walking recorded that speed and then the average of those two the run to walk the walk to run that defined their preferred transition speed and then um following that we had

uh subjects perform um longer trials so five minute trials for both walking and running so five minute trial running rest five minute trial walking at three different speeds so um and the way we determined what those three speeds were was um we knew that would be about their preferred transition speed so we wanted to get basically an intersection between the running and walking values for whatever variable we were looking at so let's just say we're looking at the breathing rate at that slowest of the three speeds we would we wanted to see running having that a greater breathing rate than walking and at the fastest of the three speeds we wanted to see walking have the greater breathing rate so there'd be an intersection um if we think about drawing a trend line for the three running data points the three walking data points and that intersection could define you know the speed at which optimize breathing rate or in the case of the carbohydrate oxidation the speed that minimize the amount of carbohydrate being used and then we compared those kind of two calculated transition speeds from the cardiorespiratory data to that preferred transition speed that we calculated earlier and we collected this data for four different inclines so those four inclines we looked at were zero five ten and fifteen degrees and um i'll i'll give those in feet per mile as well because maybe especially with this american audience maybe that's the way people best conceptualize that personally that's that's how i conceptualize it probably just because the straw that tells you how many feet

you know each mile fine so um so yeah zero zero degrees um can you guess how many feet per mile that would be coop i know you're not a huge math guy but uh maybe zero zero zero zero per mile okay there you go nice nice work nice work um and i'll do the rest of them so five degrees was five degrees was 460 feet per mile 10 degrees was 917 feet per mile 15 degrees was 1367 feet per mile so roughly which is steep steep yeah steep super steep yeah most people be walking you know that 15 degree slope anytime you know they they see a number like that pop up on straw so roughly you know it's a little bit less for every five degrees it seems about a 500 feet um you know rise per mile approximately yeah i mean so when i looked at that and i'm sure you i'm sure you picked those you picked those slopes deliberately you've obviously got flat level terrain you've got just what people would look at as a normal hill right i mean it's just a normal normal climb most people would run it front of the packers would run it back of the packers would run it things like that you've got one that's kind of an in-betweeny right like maybe the front of the pack people are going to run it and the back of the pack people are going to walk it and then you've got one grade that everybody's going to walk even the really good people are probably going to walk it especially in the maybe not in the context of like a vertical k or something like that but at

least in the context of an ultra marathon almost everybody's going to walk the last one right yeah i mean that that five degree slope being 460 feet per mile i'd say there's a lot of you know mid and back the packers that would probably walk that in like 100 milers let's say but um at the very least you know doing running intervals you know pretty much everyone's going to be be running that you know five degree incline but yeah like you said um you know i'm i'm reasonably fast most most 10 degree inclines especially in shorter ultras i'm going to be running um and then yeah like you said 15 degrees uh nearly exclusively walking outside of uh you know killing and a vk there you go always have to always got to bring up killing he's retired now so maybe it's like he's actually a little bit slower but anyway okay what so we've got this research design what did you think was going to happen what were the hypotheses that you were trying to either either either confirm or or uh or not get a confirmation on right so uh we were um fortunate i guess in the sense of um you know determined hypotheses that we had already um you know kind of looked at some similar stuff for the undergrad research so because it was the same data set i went off of those findings um with looking at the gait transition and kind of expecting what i would see so i thought that the um you know that that breathing rate ventilation rate and the carbohydrate oxidation rate i thought those those

would not be triggers for the preferred transition speed so again if we think back to that intersection of those three speeds for walking running i thought that the intersection speed for the two variables would um occur it would be different speed than the preferred transition speed and the main reason why i assumed that would happen was because for the undergrad paper that um calculated transition speed that we looked at was the energetically optimal transition speed so just looking at overall metabolic cost could that serve as a trigger which if you were going to hypothesize that any you know cardiorespiratory value would be you would think it would be energetic cost that would be the um that's kind of the big one so because that undergraduate finding was that um at least across the range of all three all four inclines that energetic cost didn't wasn't a trigger for preferred transition speed i assume that the the ventilation rate and the carbohydrate oxidation rate results would mirror that there's a little wrinkle there when it comes to 15 degrees but um we'll get into that later yeah we'll get into that but let's like boil that down to from a practical perspective right so what's your the hypothesis that you thought was going to the the hypothesis that you thought was going to unfold essentially says that the bioenergetics don't matter in terms of when humans transition from walking to running and then back

i wouldn't go so far as to say don't matter but at the very least don't serve as the primary um reason for transitioning gates at the speed that you do don't um you know you couldn't use that as the only metric you're looking at to predict preferred transition or um you know it doesn't seem that that's like the the number one end-all be-all reason why we're switching gates um but yeah i wouldn't go so far to say as they don't matter well okay i guess what i'm trying to say is is that humans when they're out there in the field they typically will notice a certain speed and a certain grade it which for which it's easier to walk versus run and everybody's had that experience they're running up a climb and they look to their right and there's somebody walking and they look to their left and there's somebody running and everybody's going the same speed and then you say oh shit well i should i should be walking because it's easier right that's whatever that's kind of what everybody thinks but the the hypothesis that that you think that you thought was going to unfold was essentially that and i guess that easier part of it would indicate that there's something metabolically that's triggering the run or the walk to run transition to the run back to it's easier right you say oh it's easier so i'm going to do the easier modality right but what you're essentially saying is that probably is not the trigger yeah i i don't yeah bioenergetics appear not to be the trigger um or that's what we hypothesized you know we'll get into results later

um that bioenergetics across the range of inclines aren't serving as the trigger for preferred transition i'll push back on the the easier you know because to me that's getting more to preferred transition speed you know the reason why you're preferring it's because it's easier or you know the reason why you're preferring one gate over the other is easier but um for whatever reason um or maybe i shouldn't say that i i but um it doesn't appear that bioenergetics are mirroring the perceived exertion like you would tend to expect right um yeah yeah and what i'm trying to set up for the listeners is it's a little it appears to be a little bit more complicated than it then at least it does to the like the lay person's eye when they're looking at that yeah you want to do the easier modality there's something from the bioenergetics at play but we could get into the actual findings right now it turns out that not that it's not going to match that all the time right so at um just kind of like we hypothesized across the four inclines um the breathing rate and the carbohydrate oxidation rate didn't appear to trigger the preferred transition speed however at 15 degrees all three of those uh you know transition speeds you know if we think about optimizing breathing rate optimizing carbohydrate oxidation rate and the preferred all three of those uh occurred very close to the same value but only at 15 degrees okay so let's kind of get into the results

right so why don't you walk kind of walk you're going to have to do a lot i feel bad for you right now that i'm thinking about it because you're going to have to verbalize a lot of figures and tables and things like that which is always very difficult very difficult in a podcast format but i can look at those and go okay i understand the results but let's try to verbalize what kind of what what the results were and then what the actual meaning to the athletes are sure so i'm gonna um just because it kind of pertains to you know the results we just talked about i'm gonna start more complicated and we're gonna go more simple so um maybe maybe that's not the right order to go in general but but we're gonna try it out so if we think about um and i guess i'll just quickly step back to the undergrad findings so um just like the the master's findings that the breathing rate carbohydrate oxidation rate um transition speeds only were the same as the preferred transition speed at 15 degrees that was the same for the overall energetic cost um transition speed and that was the undergraduate finding so it was all the same data set but what appears to be happening is that um you know at 0 5 and 10 degrees at these uh less steep inclines bioenergetics aren't serving as the trigger for preferred transition there's some other variable that's likely more biomechanical or neuromuscular in nature that's triggering the preferred transition speed so if we look at just the research for flat zero degrees um there's some good evidence that the um what's triggering the

preferred transition on flat terrain is uh just one single small muscle the um tibios interior muscle at the front of the shin so this isn't a muscle that's taking up a ton of oxygen it's not going to have a very large influence on energetic cost which is why likely you see a large difference between the energetically optimal and the preferred transition speed on flat terrain but um there's there's been i'd say five or six papers that have found that that tibios interior muscle getting fatigued or getting tired at these faster walking speeds that's what's triggering the switch to running so um likely um at least in my view a similar um something similar is happening at five and ten degrees where you know again there's not a ton of research at these moderate inclines but likely there's something more um neuromuscular biomechanical at play that's serving as the primary trigger versus energetics now if we think about the 15 degree finding which that's kind of uh different than these than these uh more moderate or more gradual inclines all of those uh cardiometabolic cardiorespiratory values uh there there is evidence that they um are serving as more of a primary trigger for preferred transition speed because all of those calculated optimal transition speeds for energetic cost for um breathing rate for carbohydrate oxidation rate because those are all occurring at the same speed as the

preferred transition speed that's some evidence that um those um energetic values could be triggering preferred transition speed so um again there's this is one finding you know there hasn't been another um paper looking at preferred transition on such such steep inclines so um i'm kind of pumping the brakes before you know running too far you know alert the medias with this amazing finding but um um in theory what's going on uh at 15 degrees uh if these results you know were replicated um in other studies um perhaps what's happening is that um as you increase the incline um the entered the overall energetic cost increase so humans don't need to work very hard uh on flat terrain you know to work at their preferred transition speed but humans have to work really freaking hard at 15 degrees to um you know be at their preferred transition speed which is why you see most people walking at such a steep incline because they can't maintain a speed um where it would make sense to run there they're far below their preferred transition speed so um so because subjects because people are working at a very high exercise intensity a very high level of you know cardiometabolic stress at that super steep incline um um perhaps then because those bioenergetic variables are close to maximal um perhaps that's that that would be a plausible theory as to why those cardiorespiratory variables are playing more of a

role in gate transition you know and if um we boil it down simply we can just say oxygen's at a premium because at that 15 degree slope you're kind of running out of oxygen to maintain that exercise intensity all of a sudden it makes a heck of a lot more sense to optimize you know just for the sake of simplicity you know oxygen at zero degrees you know you can everyone can pretty much breathe through their nose that um the preferred transition speed oxygen is nowhere near a premium that right there jackson i think summarizes it very well because i kind of look at it through the lens of we've we always like use this phrase this just came to my this just came to mind we always use this phrase like humans are smart you know we always kind of like figure out the path of least resistance and things like that but here is an example we're talking specifically about the preferred transition transition speed and i'm emphasizing preferred intentionally here's an example where the cost of transport i'm using my correct biomechanics terms here the cost of transport is actually higher when you go to that transition than it is the other way around so if you go from walking to running initially at that transition speed it's going to cost you more oxygen to go a mile than it would be if you just walked and going back to my previous example of everybody's been in the same situation where they're you know running up a climb they look to the left and somebody's walking they're looking to the right and there's there's somebody running that person to the that person to the right is preferring

a form of locomotion that is more oxygen intensive it's more expensive and it's it's always been fascinating to me because this is one of those areas where economy although it might be a small range of speed where economy isn't the biggest driving factor it might it might be and it looks like it's likely some sort of biomechanical factor like you like you mentioned earlier yeah at zero five and ten degrees um yeah i got that right um i guess i guess one thing i'll say you know just because it's the second time you've brought it up with regard oh i look to my left look to my right you know i'm running there walking um and again this research but actually i'll take that back um there's research on both on flat terrain for this um leg length actually um predicts individual differences in preferred transition speed um quite well so the longer your legs are um the more likely it is that you will feel comfortable walking at faster speeds um versus you know the small the shorter your legs are you know you might want to switch to running at a um a slower speed so just because so you know so this is for all the people out there who um get worried because the person next to them is doing different gait and then they and then they switch um you know it's i would i would advise that person to trust their gut um particularly if that person next to them is way taller or way shorter than them so you should be looking to your right at somebody the same height exactly yeah that would that would be better that would be better at least than uh um yeah than if they were a different

height but um yeah i mean it's one of those things where sure we've collected this data for the speed that you know people prefer to do it at you know and then the speed that optimizes you know some of these bioenergetic values but at the end of the day we don't have performance data um so uh and you know is it that is it better to switch at the preferred transition speed if your goal is to get up that hill quicker or is it better to switch at the speed that optimizes economy you know optimizes energetic cost and um it's it's interesting because dr crom and i my advisor have had discussions and my intuition is that humans especially you know pretty good athletes are pretty good at doing what's gonna you know just naturally do what um you know gets them to the finish line first so my kind of opinion is that preferred the preferred transition speed would optimize performance well you know roger dr crom thinks that if subjects switched at the energetically optimal transition speed so kind of changing what they naturally did to minimize their economy his view is that that would be the correct speed to switch out to optimize performance so um that's probably another research study to do um you know to to see uh yeah to kind of put a performance realm into this research um but yeah at this point we don't have any performance oriented data for you know what's the correct speed to switch at here here's what i mean you and i have talked about this a little bit i actually think it's different depending upon the event duration or depending upon the task duration so if you have a task duration like

you get you're going to have people go up green right so for a task duration like that yeah economy is super important right because you're pinning yourself the entire climb you're doing a climb that's you know if everybody's out there you you want to do like an hour time trial or a 30 minute time trial or something like that running economy and locomotion economy becomes very important and so yeah oxygen is at a premium oxygen oxygen is at a premium and so the energetically preferred transition speed as a strategy to run and walk is probably the better one but then when oxygen is not at a premium let's just say hard rock i got into hard rock today right this is at the top of my mind just like two hours ago literally before we started recording this let's go it's congrats yeah even even though yeah even though you're at 11 and 14 000 feet the entire time it seems like oxygen would be at a premium but you're going so slow right that's not the limiting factor for performance there's likely more of a musculoskeletal limiting factor for performance and then therefore switching my opinion is i've talked to roger about this too switching gates more frequently during those long duration tasks in order to you're essentially like spreading the neuromuscular fatigue around you know because you're using everything in a slightly different pattern that i think is the winning strategy in those situations and so i'm presenting them as like the polar opposites because there's this like really messy metal that everybody has to deal with but if you do but for shorter task durations i i think energy the energetically um optimal transition speed is the better strategy but

in the longer ones you got to kind of like turn that on his head and just switch things around so that the so that the biomechanics and the local the localized muscular fatigue is different yeah i don't think that's a bad coaching strategy um kind of like you mentioned we're totally within the realm of theory right now because we don't have any of that performance data so um you know that's that's why that's why researchers exist to you know provide data for um stuff that coaches already know or at the very least already think they know um but um yeah i i think you know again if we take this to the practical realm um i i think there's a lot of plausibility to what you just said and um yeah particularly if we think about 100 milers and stuff where um you know the the speed is so low there might even be an argument to um and again i'm i'm well within the realm of theory right now not uh data um i love that you have to catch that so often well i i'd want to because everyone you know in the in these day and age alternative facts blah blah blah i'm i'm purely speculating right now um but uh but like you know in hard rock there might even be an argument to um to only run on the downhills or flat terrain um because you know it's it's unlikely you know i'm excluding like some technicality or i'm trying to eat or whatever you know you can run the downhills you can run the flats but you know maybe you'll lose a little bit of time on a couple uphills by not um you know by by walking the whole thing let's say and not even trying to run some of the more gradual trains but

because you're running all those other sections kind of like you said spreading that fatigue around um and you know just kind of mixing it up all and and kind of providing more alteration um might be more of the winning strategy because yeah at the end of these super long races it oftentimes seems that some local muscular factor is um the limiting factor for for going faster so um yeah i i think uh i think yeah basically i think uh there's a there's a lot of uh um there's what you just said uh might might be it might be great but might be might be we'll hold out for it we'll see maybe 10 years from now when somebody does that research yeah 10 or five or 10 years from now when somebody does that research i'm either gonna have to eat crow or i can say i called it okay so what else what else can athletes like practically take away from this from this type of research jackson like okay we know that we we know that these things are not the triggers for the preferred transition speed how does that practically like play out though right so um i would say at this point just try to minimize perceived exertion when you're um you know climbing up the hill um you know with regards to gate transition again there might be research in the future that says oh no because we know this triggers it let's try to optimize that instead um but again that's this more speculation so i'd say kind of the big takeaways with regards to the gate transition research um so this is the part where everyone should kind of tune back in you know bringing you back to planet earth

um the for the first kind of big picture finding is that we know we know well at this point that gate transition speeds slow down with incline so um you know whether whether we're looking at preferred transition or you know more of these bioenergetic variables in all cases you know very obviously that transition speed slows down with incline so for example if we're talking about preferred transition speed um or energetically optimal transition speed on flat train um that occurs you know at about a 12 or a 13 minute mile but if we look at 15 degrees that speeds more of an 18 and a half minute mile so you know and then and then for five and ten degrees would be somewhere in there so i think it's more on flat train that transitions you know preferred transition speed occurs at about five miles per hour yet as we get up towards 15 degrees it's closer to three miles per hour so what that means is that you know it's not good to kind of anchor in your mind as to you know what it wouldn't be smart to say at this speed is when i switch gates at this incline is when i switch gates because it's a function of both you know so if i'd say oh it's 14 minutes a mile for me that might work great on one incline but it shouldn't be the same on a different incline or again let's say oh at eight percent grade that's when i switch again it's it's going to um you know depend on your speed so um just record just kind of

adding more nuance to it recognize that kind of in your mind thinking oh i'm going to switch at a certain speed or i'm going to switch at a certain incline is not the right way to go about it so my advice is what not to do again we we don't have enough to tell you what to do well a lot of i mean a lot of ultra marathon running is is i always say it's success by lack of failure right so if you're like constantly identifying all these multiple different kind of failure points and one of them would be i'm gonna i'm gonna i'm gonna walk whenever the speed gets whatever i don't think that that's a bad i don't think that's a bad framework in a lot of uh in a lot of cases let me ask you this i'm gonna put you on the spot a little bit it so everybody has yeah get ready get ready put your put your brain cap on everybody uses gps right pretty much everybody will use gps watch your gps watch knows or has the capability of knowing almost instantaneously the grade you're on and the speed that you're running you can also tell your gps watch something about you bioenergetically you can tell your vo2 max you can tell your threshold your speed at threshold and all those other things how difficult would it be to program an alarm through garmin iq right normal people can kind of do this now through garmin iq where based on a certain set of conditions for each individual for jackson brill for jason koob for you know one of my

athletes or something like that because they're all they all have different threshold speeds right for each person you're going on this grade at this speed i'm going to give you an alarm to tell you when your economically preferred transition speed is it would be really freaking hard and i guess the simple reason is twice because that was the goal of you know the original goal of the masters of research you know by by having people do these time trails of green mountains so the fact that i uh failed miserably and uh in writing that paper and collecting that data and you know maybe more importantly writing you know super complex python code to do that for me uh shows uh you know provides evidence that it would be really hard to to at this point you know engineer your watch to uh um you know kind of tell you when to switch for you somebody's gonna do that though before the research i guarantee you like there there's gonna be a you know one of the the more outdoors kind of oriented uh watches whether it's like the phoenix six when it comes out or coros is kind of trail version or whatever i i could see that coming down the pipeline and i don't know what they're going to base it on but it's kind of good to hear you say that yeah we need to like pump the brakes on this a little bit because we really we really can't put all those variables together in a formula so to speak and have it be all that applicable yeah it'll be like a whoop strap where you know it's telling us to do stuff but it's not really uh basing it off of anything

uh valuable calling out right now man it is oh god i recorded yesterday this is neither here nor there i recorded yesterday with corinne and uh and marco altini from uh hrv uh for athletes and we talked a lot about the whoop strap so the listener this that podcast will come out the week before this one i think so listeners can go check that one out and then you'll get the reference yeah and i'll uh you know you're you're very good about not letting yourself become biased with sponsors and stuff but if uh these companies come out and pay me you know uh i'd say my price would be five million dollars i'll uh i'll endorse them in full but uh we have a really high price my i will sell out but it'll be a very high number okay fair enough okay so what what else are some practical take-homes from from this research we've kind of pointed out like what not to do let's not pigeonhole ourselves into a particular speed and or combination of speed and grade to determine this run to walk transition and walk to run transition we need to trust our gut right and and and and try to minimize uh rpe to help drive that decision back and forth maybe there's a consideration in longer races where you're intentionally switching up the modes between running and walking more than you would normally do so in order to kind of minimize the localized fatigue what else can you kind of draw from from the research that athletes can kind of take

home and either work on in training or apply to a race yeah i guess the first thing i'll say is you know if we think about that trust in your gut minimizing rpe that that's more my theory you know that's that's that would be my advice in like a coaching context i don't think because we don't have that evidence that says performance is optimized by the preferred transition speed i i wouldn't feel comfortable saying that as a researcher although again that might be my coaching advice um but yeah i guess um i think we've kind of covered a lot of the the take-homes at least in my view you know you might have have one or two more things i guess um thinking again about the difference between the energetically optimal and preferred transition speed and again those other uh bioenergetic variables kind of fall within close close values to the energetically optimal transition um because because those bioenergetic transition speeds occur at zero through 10 degrees faster at a faster speed than the preferred transition speed you could make an argument for um at the very least um practicing and training switching out of speed slightly quicker you know maybe 10 quicker than you naturally would and um you know that if you kind of got more comfortable doing that that would kind of bring that difference between the preferred and the bioenergetic um optimization closer together um so there's

perhaps an argument for doing that um but i'd say you know the biggest thing to do in training is just get comfortable switching gates you know if you if kind of uh kind of like you say as a coach you know if you can do something in training it's a lot easier to replicate in a race so if you feel comfortable you know even if it's not based on any large scientific principle if you feel comfortable switching back and forth on a climb between running and walking and training and you feel comfortable doing it um you know at the speed that you kind of find yourself doing it at it's going to be a lot easier in a race to be confident and you know not feel the need to turn to the person next to you and see which gate they're doing well and you you started to bring this up and i want to peel peel it apart just a little bit more there is this concept that running and walking are skills right and we see this play out in the in the context of uh in the context of the competitive arena where races that have a lot of hiking have kind of like almost different not different winners but you see people perform differently i guess as opposed to races that have a lot of like flat level terrain right you've got the athletes that are good on mountainous train you've got the athletes that are really good on on flat terrain you had this brilliant uh slide uh in in in one of the parts of your presentation where it's a picture of elliott kipchoge and a not equal sign in the picture of killian jornay they're both fantastic athletes and they

might be very similar from a cardiovascular standpoint right you put them on treadmill they if you're blind at the speed but they might be very similar in terms of their cardiac output and their vo2 max and things like that but then you put them on the marathon race course and they're way different you put them on a mountainous race course and they would be way different so why don't you talk about that aspect a little bit the skill aspect that kind of that that really gets uncovered when we're testing people on flat level terrain and on inclines sure and yeah no the uh i didn't want to interrupt you but uh when you started out saying oh the the people who do well in these steep mountainous races where there's walking are you know different than when there's these more flatter or buffed out train i'm like yeah that's the reason why i'm sponsored you know because there's not they're not all just these flat level races because i man i would be in trouble if uh if everything was you know beautiful buffed out smooth not too steep terrain so thank goodness i would say that um that the winners of these steeper races are different um but yeah this um you know that was a brilliant segue kind of into the second part of uh my my research um which was looking um not at gate transition specifically but looking at locomotor economy so looking at running economy and looking at walking economy and using um economy as a proxy or a measurement that in part um kind of is looking at um this idea

that these different modalities are different skills so obviously from a performance perspective you know it's it's easier it's maybe easier to recognize the different skills kind of like we just said you know killian killian is a you know a great steep runner but he's you know not going to win the olympic five can anytime soon likewise kipchoge hasn't um you know uh hasn't won UTMB and and likely will never in his life um notice how i said it's a great statement but nothing's possible right ellen kipchoge nothing is impossible um uh but but at the very least yeah the the skills are very different and you know a lot and maybe maybe to bring it a little closer to home um i mean you see really good ncaa cross country and track athletes jump into the trail world and um they don't have immediate success and some of them ever have success so um for sure i'd say it's pretty well established on the performance side of things that um that that the ability to succeed in in these flatter races doesn't always correspond to the ability to succeed in these more mountainous races so um yeah uh we we measured locomotor economy you know for walking and so walking economy and running economy um and kind of use that to kind of unpiece this question and then look at this idea of skill a little bit more you know and i've always the way that i've always explained that is is in the in the running world and this has been particularly accentuated in the last few years with the shoe

revolution and all the carbon fiber plates that are getting put in the road shoes is that running economy is kind of the the king and queen maker you know in the in the road running world you have athletes that are very very similar from a vo2 max perspective their running economy essentially separates them from a from a performance perspective you don't see that correlation as strong in trail running meaning if you lined up the top 10 people at UTMB and you gave them all uh uh that you gave them all a stress test and determine what their threshold was and what their running economy threshold is and things like that those numbers that the bubble of those numbers would be fairly large as compared to if you look at the top 10 for international road racer or or something like that so it goes back to there's a skill component that is at play that absolutely has a big thing to do with performance yeah and you might want to lick link to a former uh podcast guest uh guia means uh paper that um i think it's titled something like um you know how running economy isn't as big of a player in the you know in the ultra world uh you know as compared to the road running world um yeah you know there's there's a um a lot a lot of variables at play you know in these mountain races that um kind of make any one variable in this case locomotor economy um not kind of the the kingpin and and even if we make it a little more complex you know it's at the very least in the road running world you know it

seems like it's all about three variables at least vo2 max lactate threshold and running economy from those three um variables um you know and we can look at uh joiners michael joiners paper on this um we we we can pretty well predict um you know performance from those three variables and it's all about optimizing those three variables here's the take-home lesson though from that right it's this one thing to say okay running walking or skill and running economy might not be as important in trail running as as in road running from a coach here's the actionable piece that all the listeners can kind of take home you you if you're training for a road marathon you will absolutely absolutely want to introduce training interventions to help improve running economy specifically think of strength training think of doing like bounding drills and things like that those interventions are very specifically aimed at improving running economy just like the super shoes right same proposition get a carbon fiber plate in your shoes you're going to improve your running economy your performance will therefore improve there's not as compelling of an argument to do those specific running economy types of interventions in trail running because improving running economy is not as linked there's the caveat is not as linked to performance from a trail perspective particularly when i would say the trail trail that the athlete is competing on is is very technical so the way that

i've always approached it as a coach is i'm just going to get the running economy gains through training right just normal run training normal doing intervals we're kind of do and then leave all of the other specialty interventions i don't i don't ever look at those as a thing to go to kind of chase around from a from a from a trail running perspective i would rather get the 95 improvement in running economy just through the normal normal training process and not chase around the other stuff yeah and i'm answering this question i'm responding now as as an athlete you know not as a as a researcher but um i i i feel similarly you know i um some of it's that i don't like to you know do heavy strength training or bound and drill stuff like that but um but yeah i don't even think it's probably that helpful in the context of of race performance you know considering the events that um you know the mountain races these you know ultras that um are kind of my specialty um and if anything you know the closest i'm kind of coming to specifically doing workouts to improve my running economy are more just pretty high intense um running workouts so vo2 max you know you're you're just from vo2 max workouts or let's even say you're hopping on the track and doing like hard 200s and 400s you know that's you know maybe even faster than vo2 max even from just just these really high intensity running workouts you're likely as a trail runner going to get a slight boost in running economy just because of those high force outputs and kind of the response then that you know maybe has on your tendons and stuff

you know for us for us slow pokes just running through the woods that might you know just by doing vo2 max intervals that might even be enough to give you a um significant boost in running economy without even having to mess around with any you know fancy uh um gym exercises or whatnot well i was at the i was at the running event uh this past weekend's big trade big huge running trade show in austin texas that happens every year for the listeners that that aren't aware of it so all the all the shoe companies go there all the specialty retailers all the device manufacturers and things like that and you're so you're starting to see you know one of the big themes this year was the carbon fiber plates everybody's kind of got them there's even companies that uh will put them in insoles and uh there are even companies that are now targeting the shoe manufacturers with hey we've got the best carbon right just like they do in the kind of in the cycling world and it's starting to pop up in the trail running space as well and you know how the shoe manufacturers work they've got a platform and they just kind of plug and play that platform and make slight you know design modifications and and i look at that and go if you're putting a carbon fiber plate in there to improve running economy and it doesn't matter in this sport like i don't understand i don't understand i kind of don't understand the purpose and i asked a couple reps about that and they were just totally freaking clueless you want to have a carbon fiber plate in there for another reason great but don't do it for the running economy reason i guess that's what i was saying i mean i think if we're thinking about other

reasons the carbon fiber plates more likely to have a detriment you know because uh like yeah i mean i would be absolutely terrified if i took my uh alpha flies you know my nike you know alpha flies out on the trail you know i'd probably break my ankle with you know the first time i had to make a like 30 degree turn in the trail so um yeah i'd be i'd be more worried i'd be more worried um i'd be more worried than excited about a carbon fiber plate in a trail shoe personally but um i'm not sponsored by north face so it's okay for me to say that it's poor north face shoes like i said if you put a if you put a carbon fiber plate in a trail shoe for another reason besides running an economy great if it's if it's fit for purpose great but if you're telling me that you're putting this in there for running economy gain on the trail i'm just going to look at you i'm going to look at you sideways so don't start doing that shoe manufacturers um okay so we we've got we've kind of got to the part where we're we're looking at these different performance outcomes as not being driven by running economy in this or not predominantly being driven by running economy and the take-home message just to encapsulate that for the athletes is from a training perspective it's probably unwise to go around and chase that specific gain because it's not material to the outcome take the gains from the normal training process and have that be it and this is a i just thought of this this is an area jackson where like the research and

the things that you're uncovering it has impact far outside of what you're intentionally studying right because i can look at this as a coach and i'm like okay that tells me what not to do and that actually is just as good of a directional arrow in a lot of cases as what to do because i know a lot of the right things to do and if you're saying okay don't go chase don't go down this path don't go chase this direction from some you know like casually related research that's great for me as a coach yeah and i guess if you ever intended it that way though yeah i mean we uh i mean ultimately you know i'm i am an athlete and um you know have a bit of a have some coaching experience and whatnot so i think when it comes to questions that i'm interested in looking at certainly you know i'm i'm thinking about this within the context of exercise performance so um maybe it wasn't intentional but at the very least uh uh likely you know doing research that's applicable to coaches and athletes is subconsciously something that i'm uh you know probably probably gearing things towards but um yeah i mean now that we've uh kind of bad-mouthed economy or at the very least said what it's um kind of kind of what it's not you know maybe uh well what maybe we shouldn't do with respect to locomotor economy um the reason why we collected this data and analyzed this data was more for using it as a measurement of skill and there is going to be some limitations of that um because you know economy doesn't completely equal skill you know particularly if we think about

skill being performance we just talked about how particularly in ultras economy isn't the number one driver of performance that being said though if we collected running economy data for all our subjects for running all our subjects for walking at zero five ten and fifteen degrees and i'd say because we had enough data um and could run enough comparisons i think there are some useful findings with respect to um you know seeing how comparing running economy on flat to running economy on uphill train comparing walking economy on flat to walking economy on uphill train comparing running economy on flat versus walking economy on flat or comparing running economy on uphill versus walking economy on uphill i think i got all all four kind of big comparisons and um i think the usefulness there is it tells us so so we looked at correlations and we looked to see how well locomotor economy and kind of these four different um these four different modes you know flat running and walking versus steep running and walking how well they translated from one mode to the other because if we found a strong correlation that would make an argument that they're similar skills and if we found a weak or um no correlation that would provide evidence that um they are it um that they that they're different skills and from that you know or getting back to the coaches athletes um yeah if something's different

skill if if if we find based off the if we find two modes didn't correlate strongly thus meaning that that's evidence that they're different skills then you likely should train both skills and you couldn't utilize training to train both skills at the same time um you know if your races had had both of them had two different modes of it that didn't correlate yeah so you're screwed if you're not you're not screwed but you're not going to perform it as well at hard rock if you spend all your time running up and down hills you'll do okay but you'll do a lot better if you spend some of your time walking uphill right so yeah i'll get into the results which which support what you just said so um so like i said there are kind of these four different comparisons you know we can think about running on flat or gradual to to running on steep you know and then walking on steep versus you know walking on flat and gradual and then kind of mix and match do all these comparisons so what we found was that uh or i guess i said that slightly differently i'll just jump into our findings um we found that um yeah at um for running economy we found that at the small incline differences so at five degree incline differences so zero versus five degrees five versus ten degrees ten versus fifteen degrees we found quite strong correlations so in effect that um when we compared running at two different inclines when that incline difference was only five degrees small incline difference that they were similar skills same findings for walking

economy the walking economy for zero versus five five versus ten ten versus fifteen also correlated strong so these small incline difference strong correlation within the same gate so in effect similar skills within the same gate uh at the small incline differences now we also looked at the incline we also looked at the economy comparisons of the larger incline differences so think zero versus ten degrees five versus fifteen degrees and zero versus fifteen degrees and then we find that um those strong correlations um or then we find that the correlations get worse so um at those 10 and 15 degree incline differences for both you know comparing running economy to itself and comparing walking economy itself we found that those correlations weren't that good so in one or two instances maybe they were moderate in a couple instances they were you know it was absolutely no um you know no no obvious correlation um so yeah it appears that um once you get to um you know a 10 degree incline difference that all of a sudden even within the same gate those are different skills so you know it makes sense that killian and kipchoge are uh are different athletes with with a different skill set could you uh i'm gonna ask that question later because that's gonna really put you on the spot let's cut let's let's once again let's take that and move it to practically what athletes should do so what i hear from that as a coach is that the specificity matters

right if if they are truly different skills and they're truly different skills across the different grades and they're only they're only correlated within a small with within very small differences if you have an athlete that is competing with a in a race that has all of these variety of of grades they're best served to do that in training as well exactly yeah so it sounds so super simple but this research actually says yeah you should actually be doing that right principle principle of specificity so um if we think about kind of the research that's been done prior to this that's been pretty well established for running economy it's well known that at the smaller inclined or i'd say there's good evidence at this point that and even prior to my research that at the small inclined differences running economy correlated strongly but at the larger inclined differences those correlations diminished um so basically my research filled in the gaps a little bit for walking economy finding that those the walking economy correlations parallel the running economy um findings um but yeah again getting back to practical stuff training with specificity with regard to steepness of incline yeah but then also just think about it if you're reconning a course right if you're reconning a course you should be running and walking when you think you're going to be running and walking during the race and we see this at the western states camp

we see people who do soft rock you know and they try to run everything that's probably not the best way to get the most physiological adaptation and skill acquisition to since we're focusing on that word out of that recon because you're going to use a different skill during the race because the race duration is going to dictate that you can't run everything right and uh you know i'm kind of outing myself right now as a frequent podcast listener of yours but um yeah it's it's it's one of those things where in training it's really easy to run a crap a shit ton more than um you're going to in a hundred mile race you know come mile 30 40 50 whatever but um yeah i would say that um my findings um support this idea that particularly when you're doing these longer ultras where you are going to be walking a lot more slow down and practice walking um because you know that walking those walking economy uh correlations are going to are because walking economy well i guess i didn't mention this earlier but um my findings for comparing running and walking economy at the same incline so comparing running and walking economy at zero comparing the running and walking economy at five comparing the two at 10 comparing that at 15 also didn't find strong correlations they were more moderate so they were so comparing running and walking economy at the same incline um had worse correlations than within the same gate at the small incline differences but generally better correlations within the same

um gate at the larger incline differences so comparing the two gates of the same incline moderate you know moderate um correlations but those that's not a strong correlation so i would say yeah you know it's one of those things in training where um force yourself to walk um more in training or at least uh you know if you're going to be walking more in the race because based off these economy findings running and walking are different skills with um economy not translating um particularly well from one to the other yeah here here's how i do it for athletes and this this research i i i i'm not going to say i developed this because it's something's probably done it way before i did but when i have an athlete i try when i have an athlete that's that's training for a mountainous event i know they're going to be hiking a lot i try to forecast what percentage of time during the race and this is really important it's a percentage of time not percentage of miles but what percentage of time they are going to be walking during the race and if you look if you know the the the capability of the athlete the fitness of the athlete and you can look at the race profile you can get that close you're not going to like freaking dial it in but you can get it close if you have gps data and you have cadence data from your watch you can you can and they've done the race before you can get that super super precise or you can look at somebody else's data that has done it before and you can get that and you can peel apart the cadence data that way you can get it super precise but you can get it close and then what i try to have the athlete do in training

is match that run and walk percentage that's the first thing and i almost always find that the percentage of walking or power hiking what are we calling it now to make it not sound like everybody's going slow power hiking right that's the that's i don't mind i don't mind sounding slow i'm just going to keep using walking okay we're going to use walking the amount of time that they need to that they need to bump up is double usually it's and sometimes it's triple you know they're spending 10 of their time uh walking during training and they need to spend 30 of it during training because that's what they're going to do in the race i mean it really is a it's it really is a one to three or sometimes even four x and sometimes that's hard to do because they don't have the training but i guess my point is is the one of the ways that i unfold that skill component as a coach is making sure that the just simple percentage of walking is roughly matched in training as compared to what the race forecast is and the second one and this goes back to the grip the specificity of the grade is if you have a perfect situation you try to get them on the grades that they're going to that they're going to experience during the race which is usually kind of all over the map but to but to simplify it i just say listen if the race has 400 feet of elevation change per mile that's what we're going to target in training and then that way there's enough it kind of forces the

variety i guess is what i'm saying you try to get enough variety in there to induce the biomechanical adaptations what we're not doing and we always kind of have to go back to what we're not doing as well or this is what i what i what i don't do is say i want to see x vertical feet this week or why and i get this question on instagram a lot how many vertical feet do i need or whatever i've never related it like that i've always looked at it as what is the rate of change compared to the rate of change during the race because you want the biomechanical you want the biomechanical specificity and i guess in that case there's what i'm trying to say is there's no overload that's specifically associated with a number of vertical feet like we think of a mileage overload or a volume overload i need 10 hours per week to get an adaptation or whatever like that doesn't exist or i don't think it exists in the vertical world because it's all related to the biomechanical specificity in terms of feet change per mile that that's the way i've done it as a coach i don't know if you think about it any differently as an athlete though yeah no it's uh what i'm hearing you say is you know earlier i mentioned with the gait transition stuff you know so i guess throwing it back to a few minutes ago like oh you know it's it the gait transition is a function of both incline and speed don't don't narrow in on just using one of them as the change so i hear you say what i hear you saying is you know don't worry about just miles don't worry about just vertical feet worry about the rate of them you worry about the combination of them um because you know ultimately what we're targeting is within

the time we have for training um you know being specific with regards to the incline is that do i have that right yeah 100 yep cool and then i guess another quick clarifying question at the beginning of what you just last said you said um oh i find three or four times is they need to walk three or four times as much is that referring to what they were naturally doing so maybe naturally someone like dylan bowman's doing 10 walking and training but when he's training for hard rock maybe you need him doing more like 30 or 40 percent yeah exactly exactly and i i use that i use that one to five x just to illustrate how big the discrepancy is for most athletes and so for everybody there listening right now like think about that i'm doing x race and i'm going to and let's just say the race is a 10 hour race because i'm going to make the math easy for me right 10 hour race and three out of those 10 hours i'm going to be walking if you're training 10 hours a week three hours during that 10 hours of week training should be walking to match the race specificity and most people when they think about that they're like i don't walk at all or i might walk to the grocery store you know or something like you know that doesn't count as training at that point but i guess my point is is it's it's most people grossly underestimate the percentage of hiking that they are either going to be doing during the race and or the percentage of hiking that they need to do in training it's interesting what

uh talking through this has made me realize a training error that i've done myself with regards to running and walking so uh so so i've i've kind of always agreed and understood that it's important to walk you know a proportion of you know a ideally a um similar proportion in training as you'll do in race day so the way i've kind of done it in the past is oh i'm just gonna perform um i'm just gonna spend a couple days hiking up super steep um you know inclines in boulder where i'm gonna have to walk and even though it's steeper than i'm going to be racing on it's going to force me to walk and you know i'll get that proportion walking you know this is perfect great and i don't have to sacrifice you know any uh cardiovascular fitness because of maintaining a high output because i'm on steep terrain but what i'm realizing right now is that because you know i i'm hiking at a much steeper incline than i might in let's say a 50 miler and because that's maybe a large enough incline difference that the walking economy on the steep terrain that i'm training likely won't translate to the walking economy on the more gradual terrain that i'm going to have to walk in training so what i'm now realizing is oh okay what i thought was great oh i'm going to hike up fern canyon and that's going to help me when i have to hike you know during the quadro 50 miler probably not because those incline differences are probably more on the range of 10 degrees so the walking economy won't correlate as well so i probably should actually have been um walking more gradual um more gradual train because

those appear to be different skills so um yeah thanks thanks for uh thanks for helping me train better well i was going to ask you that's why that's why we were stumbling all over each other because i was going to ask you that very question what are you going to do differently now that you know that so you already you already answered that and i will tell you as a coach this is not something that i would do differently but it's definitely something that i have realized i need to emphasize more with athletes is this one walking more to walking and running specifically on the grades and the terrain that they're going to be experiencing during the race just emphasizing that more that much more during the during the training process as much as the athlete can do you know i mean some people they just don't have access to you know different types of train but i i've kind of viewed it i think a lot of athletes get a little over prideful with having to run every single step you're laughing because this is probably you as well because they don't want their intensity they think that that their intensity is going to go down and therefore the effectiveness of the workout goes down when they switch from a run to a walk but a they need this is really important by the way i think all the coaches and athletes that are listening to this need to take this into consideration the more effective um the more effective training activity or training run is going to be the one that is the most biomechanically specific in this versus the one that's the boat that's the most intense so let's just say

that you're doing a normal training run right and you need to walk more right walking more at a lower intensity is a good trade-off versus running more at a higher intensity and in most people's psychology is reversed right because they're so intensity focused and they think that the higher intensity is going to elicit a superior adaptation but the way that i look at it is it doesn't matter during an endurance run if you're at like 60 of your vo2 max or you slow down to a walk at in in locomotive 50 of your vo2 max the adaptation of between those two intensities is virtually identical so since the cardiovascular adaptation between those between those uh intensities are virtually identical i would rather take the advantage of getting the biomechanical specificity along the way and plus then it's easier so you can do more volume you can recover faster and stuff like that and i guarantee you there are a ton of athletes and coaches out there that don't really think about that they think about going a little bit harder on the climbs in order to maintain a run and they think that that is more effective because of the increase in intensity and there might be there might be cases where yeah if you're not doing any intensity that might be the more effective workout but as long as you have other organized intensity outside of that slow down till walk you get the biomechanical specificity and the cardiovascular implications are almost identical between those two intensities

right yeah maybe a succinct way to say it is you lose one percent you know in terms of you know a cardiovascular stimulus for the sake of a 10 to 25 percent increase in you know specificity and and you know the performance implications of that yep bingo yeah nail on the head right there all right man we're gonna let you go we already went through all the things that we wouldn't do and that we're gonna do differently uh links to everything will be on the show notes jackson do you want people to reach out to you and heckle you on social media you can give your handles now yeah i'm fine with that um i i actively use strava and instagram so i'm happy to happy to um see people over there and what's your instagram handle oh my name maybe there's a maybe there's a dot in between the first and last i know i'm not sure all right i'll link it up in the show notes man thanks for coming on the uh podcast today man thanks for doing the research like i said links to the show notes will or there'll be links in the show notes to everything that we talked about man this is fun yeah no it's uh doing doing the research sometimes you know it can get a little lonely in there so when i have a chance to kind of present whether it's you know at a research conference or even just more informally on something like this it's uh kind of kind of makes it all worth it in a way so yeah i appreciate you giving me this platform all right folks there you have it there you go much thanks to jackson for coming on the podcast today there will be links in the show notes to jackson's presentation i hope everybody goes and

checks those out and geeks out a little bit further and i also hope everybody takes to heart this extremely important concept that running and walking are fundamentally different and that we need to train for them as specific modalities when we're thinking about training for particularly mountainous trail and ultra marathon types of events in fact this is one of the areas that i have changed in my coaching the most since first working with ultra runners and that is to emphasize walking and power hiking more throughout the training process than i did when i first started working with trail and ultra runners thank you to all the listeners that are out there if you had feedback for this particular episode you can hit me up on social media i always appreciate those comments you can share this podcast with your friends and training partners and you can give it a rating on apple podcast that really helps the podcast out a lot i appreciate the heck out of each and every one of the listeners out there and as always we will see you out on the trails you