How To Optimize Steep Running With Rodger Kram PhD | Koopcast Episode 69

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 is all about steep running and hiking and how to make the most out of your efforts out there on the trails every single week i have athletes ask me how do i become a better uphill runner and when do i switch between running and hiking and is one of the most common questions in trail and ultra running and one that we've also discussed on the podcast before but we can never learn enough about this subject so on the podcast today i have the esteemed roger crom PhD and professor emeritus at the university of colorado boulder professor crom's contributions to the biomechanics community would take a whole lifetime's worth of podcasts to actually discuss and i'm very honored that he would at least sit down with me for one single podcast to discuss some of these topics he has contributed immensely to our understanding of running biomechanics the oxygen and energy cost of running and how biomechanics affect human performance roger has built a legacy that will extend far beyond his teaching years by not only helping to pioneer the field of biomechanics itself even before that field existed but with the

university of colorado's biomechanics lab which is one of the most sought after laboratories in the entire world for biomechanics research roger is also a paid consultant to nike and contributed greatly to their breaking two project providing important research and counsel on the effort and in the show notes i will link to a few of the papers that roger was recently involved in that assisted in that particular effort however most importantly for trail and ultra running roger's biomechanics lab built a steep treadmill that goes up to a 100 grade which is kind of unfathomable for most runners and they did that in order to study uphill running after being inspired by none other than the incomparable killian journey as a personal note i took some undergraduate courses from roger and he provided some technical advisement to the first edition of my book which i am forever grateful for you'll appreciate roger's expertise his passion for the sport and his passion for performance as well as how he can communicate complex topics in an understandable way all right i'm gonna get right out of the way let's get right into it here's my conversation with the incredible roger crom how's a semi-retired or retired life been treating you before we get into it really good yeah i uh um i've been getting out on more skiing and uh uh uh but i took on another project of uh my wife and i bought a a new house so uh we're uh renovating

that and overseeing that so uh i guess but yeah life's good i i feel like i can keep up with things you know it's like oh well i can do that later this week and and then i actually get it done later this week instead of like just disappearing uh into oblivion so well you were busy throughout the course of your career i mean not only were you teaching but you already you had like a graduate you know student army it seemed like like pumping out publications and then the lab and then your consulting work with nike all on top of that i mean i can imagine how projects can get shoved to years down the years down the road with all that going on yeah actually i have a big one that uh i hope to take on uh is uh writing a book so uh you know some form of a book i don't know if it'll be a book book or a ebook or but uh yeah sign me up for the newsletter when it when it releases because i'll be first i'll be first on the list to buy it you're the second or third podcast guest that i've had in the last month that's work that has is it is working on a book or has it kind of like in the pipeline yeah yeah i i think i want to write to uh write it for my 18 year old self like some a kid who likes to run who likes science and like uh you know and then the whole world opens up it's like whoa i can do this for a career year wow this is pretty cool so i i like the fact that you have tracked your mile pr for how many years

now in the bio that you sent me that i read right before this how many years not to date yourself roger but i think we're past pretentiousness yeah well i'm i'm 59 so it's uh and i ran my fastest mile when i was 18 so yeah it's what 41 years so uh yeah i i don't track it every year i just was like i wonder how much i've slowed down and then i figured it out and it's it's kind of it's maybe a good lesson for your listeners actually and that is that you if you don't use something you do lose it and and it's it's inexorably slowly and small you know like like a hundredth of a second every day i slow down in a mile and and you know you're like well where did it go what did i do it's it's not what you did it's what you didn't do and that's maintain speed work and and you know turnover and and uh i think that's the main thing i mean you have this you have this like really long academic career that kind of started with running right i mean you're a runner in high school and you you know you've mentioned to me in class and also in your bio that you kind of take your you took your first lactate measurements you know as a teenager in your mom's laundry room and things like that so you've always been interested in locomotion i guess is what i'm saying and not just human locomotion but also animal locomotion of which you've researched a ton correct right yeah that was what uh really all i did before i uh well mostly what i did before i came to colorado so um yeah i've studied a wide variety of

animals say i i grew up in pittsburgh pennsylvania and uh saturdays was uh they had these classes sort of extra classes at the natural history museum and uh and we had a great zoo so uh yeah i've been fascinated with animals it was really hard for me to choose when i went to college which science to study because i love mechanics and i love biology and i did really well in chemistry and uh and biomechanics as a word and as a field really was just just barely beginning so it was it wasn't like i could major in biomechanics that wasn't a thing and uh but i i guess i tended tended more to the once we got out of physics mechanics once we got went into you know quantum and relativity and stuff i i kind of like lost interest it wasn't any it wasn't real for me i loved mechanics and then so then i drifted more to biology and physiology which is obviously pretty real and we all experience so and and more recently and more more recently for you is like the last 20 years i i'm uh by my calculations um there's been a really heavy run focus on things and you you had goes without saying you and your lab have have had your fingers in like a number of different pies in the running community from footwear to running economy to uh i mean i had alina grabowski on my podcast a few weeks

ago talking about prosthetics and and run performance and she's fantastic and and now most recently since this is primarily a trail and ultra running podcast you have this steep treadmill in your lab this one of a kind steep treadmill that if anybody were to have ever were to ever seen it they would look at it and go oh my gosh i cannot believe that this is like a training tool but it's something that you that you and you and your colleagues in your lab you guys built right you guys built this this steep treadmill specifically for the purposes of research and so i think to start to paint the picture like describe the treadmill for us okay uh yeah we we we uh the the cutting edge of science you often have to build your own tools like they just don't exist if you wanted to um you know at the crazy extreme if you want to study the atom you need to make a particle collider right and those are a little bigger scale than making a treadmill but um the steepest treadmill you can find is i think made by um nordic track yeah commercial one and uh and most of the gyms or or home home treadmills measure things in percent uh percent grade but uh that gets kind of it gets like a weird number so we go with degrees because 45 degrees is a hundred percent by the way grade is calculated and and that everybody's like what do you mean a hundred percent like straight up i'm like no no not have straight up so so anyhow uh there's a

little bit it may be an interesting story for your crowd and that is that um uh killian jornay was giving a lecture at the boulder running company and uh and alina grabowski and i went to to hear him and uh and it was very you know i don't know if you've heard him or met him but he's he's contagious you know he's he's he's a really intriguing guy and uh and i elbowed alina i said you know we really ought to study this trail running stuff because we she and i run together and and uh and we had uh we had never done anything specifically for really uh for trail or steep stuff so um and we hadn't we had an old treadmill that we had made ourselves um because we uh my lab but uh we made the first force measuring treadmill a treadmill that uh you can measure the ground reaction force underneath the feet with every step and uh we had to make this treadmill super light and pretty small so uh so we had that around and uh we have this stuff called 80 not 80 20 we have it uh it's unistrat it's the stuff that it's the metal metal tubing that holds up stop signs or no parking signs everybody's kind of familiar with it but it turns out it's a great um lego for for big kids and uh we use it all the time we can make things very quickly and bolt it together and make a frame so that's what we we made a frame that uh we could uh lift and then bolt in place at

whatever angle we wanted it it goes to well it could go to 90 if you wanted to um it could overhang but but we're not doing climbing locomotion right now um and uh oh i should give credit one of the students who worked on that was uh mandy ortiz who um was a university of colorado student but um more relevant she was on the uh united states mountain running team i think she was junior yeah she may have been world champion as a junior uh and her mom's a pretty famous uh ultra runner too she's won pike's peak like some crazy number of times and she's i don't want to guess her age but you know her daughter's in med school so she's she's uh she's a pretty impressive lady um anyhow mandy mandy and i put that together we we made this frame out of uh uh 80 20 of uh unistrat and uh we started to run into a couple of problems i i guess i'm start i started to realize why commercial treadmills only go to a certain degree and and that is uh first one was uh was friction uh so when it gets too steep your feet are slipping and so we had to put um uh adhesive sandpaper on it i had another student brand fam who's a longboarder and he said oh you want this stuff called vicious tape which is is really really sticky and really aggressive sandpaper and we put that on the treadmill so that

we wouldn't slip what you're describing is this people like literally their foot is slipping down off of the treadmill because of the incline exactly so you're basically putting grippy sandpaper on the bottom of it or on the belt yeah you couldn't you you couldn't go at the angle and and then then the second thing we noticed after we weren't slipping was that at at steeper angles the um your body weight is pulling the the belt backwards right as you as you step on this thing and the motor on a treadmill is designed to make it go it's not designed to slow it down and so um we realized we had to put a load on the treadmill on the motor and so we have a um an extra like belt pulley and we hang weights uh over the over the uh belt pulley so that uh the motor has something that to work against and it can maintain a constant speed so um before any of your listeners say oh i want to make a super steep treadmill um you yeah sure you can put sticky tape on it or sticky sandpaper that's safe but um if you take a regular treadmill and you incline it too steeply um the you'll ruin the motor the motor will uh will will it just won't work so uh you have to figure out a way to provide a resistance to the uh to the to the motor if you if you do want to try this so don't diy it unless you have a biomechanics team

behind you assisting you with the process is the is the is the end result yeah but i don't want to discourage diy uh uh um nicola giovanelli who was the second student to work on the project um who you should have on your podcast he'd be great um nicola um he bought a treadmill off of ebay in italy for like uh 50 euros and and he modified that one so uh you can you can get you know just don't take your brand new january 1st christmas present uh five thousand dollar treadmill and try it uh get a cheap treadmill and and uh and try to modify it sure i actually did have nicola on my uh on my podcast is episode 61 for the listeners okay he's he's fantastic we geeked out on polls as you can as you can imagine but what you're telling me i did not know the origin of this story um as many conversations as you and i have had uh killian being the the the origin of the steep treadmill you are literally going to a presentation by killian journey of course it's killian right in boulder out of all things yes and you decide that you're going to start studying trail running and one of the mechanisms you needed to study trail running was a treadmill that exceeded the the capacity or the capabilities of the current treadmills that were out there yeah exactly i i i really got got hooked on the vertical kilometer and and that um uh which which is really not well it's it's they seem to be held in conjunction with

ultra races but um it's a it's a totally different energy system and yeah but but it's you know i've been a scientist i guess i've always been a scientist really children are scientists too and uh um you know the idea that it's a kilometer like oh yeah a thousand meters every you know that right that's a nice uh nice metric for uh and uh um and that there are different places in the world where that are better or worse and and you know you said it was been about 20 years since i really focused on running and that's when i moved to boulder to the university of colorado and uh and it was certainly an attractive aspect of it that that i knew i'd have really good subjects and um and but more so that in my personal life i could be in the mountains and you can't you can't really live here and run without thinking about uphill i mean it's it's it's inevitable right you know it's the challenge it's the beauty and um so so we have done a whole series of studies on uphill running and i appreciate the way that you have approached the problem because when i first started working with trail and ultra runners a lot of the practice that we used a lot of what we were doing with trail and ultra runners was extrapolated from research that was done in the traditional endurance domains and particularly like

the 10 kilometer and in the marathon but the way that your your lab kind of approaches like let's just understand what the cost of transport is let's understand these very basic biomechanical concepts of uphill and downhill running and then see if we can translate and then and then i could take that as a coach i could take those things and try to translate it into training prescriptions and one of the things that you first kind of started out with was let's just find the most if i'm going to use the word efficient and it's probably a bastardized way to to to use it for bob talking to a biomechanist but what's the most efficient way to climb a certain distance like what grade is the best one to pick if you had a number of different choices and you guys use the steep treadmill in this uh in this research yeah absolutely so so uh this is something that everybody thinks about a well not if you're if you stick on the trails but if you run kind of off trail and and other animals think about they don't know if they think about it but they they act upon it is uh what's the best angle to go up this hill should i go straight up this hill should i uh and and it's it's probably a lot up here different personalities um initially your initial guest is like let's just get it over with and go straight up the fall line um and then other people are more methodical and say like no i'll zigzag up and um and uh and and

maintain a maybe i should maintain an angle that i can run at rather than taking it so steep that i have to climb or walk up it and um it was pretty abstract um but but a a scientist named alberto manetti had looked at uh and i think he had done it he looked at more uh the trails in europe for where people use donkeys and horses and so on and they have a certain incline they they they all kind of converged on hey this is the best incline for uh hauling stuff up to our mountain hut with a with a donkey um and other scientists biologists have looked at um i've been thinking about following up on this uh they looked at tracks uh on presumably in the snow uh that that animals take up a hill right did they uh did they go up does small animals go up a different angle do big animals go up straight up the hill anyway there's still plenty of questions to to pursue there in a more biological setting but but um yeah nicola and uh mandy ortiz and i uh we started looking at i said this vertical kilometer thing has got me i'm really curious about it you know and and uh and what's the record and and then you find the record is was at that time was just under 30 minutes right and um i'm like wow a thousand takes 30 30 minutes to go a kilometer you know i can do a kilometer and you know under four

minutes on the uh on a flat ground many many of your runners can do it and much faster but it takes half an hour so um and then we looked at the angle of uh that the records all seem to be set it uh at fully in switzerland and and it's an old uh what they call a funicular a cog railway uh line that was abandoned and it's at 30 degrees the average incline is 30 degrees i'm like 30 degrees i love 30 degrees it's you know the sine of 30 cosine of 30 everybody knows this triangle 30 60 90 triangle so it's like 30 degrees yeah and and at first 30 degrees doesn't seem like that steep when you draw it on a piece of paper but when you incline your treadmill to 30 degrees remember that's 50 percent that's not uh it's not 30 it's it's 50 it's 30 degrees so that's the that's where the record was and we looked at other vks um around the world and found that uh that they were slower if there weren't really any that there's maybe one i think in italy that's slightly steeper and the records are not set there and then there's a couple in the western u.s and canada that are more gradual so um yeah so that study that was really where we got our feet wet and and and we we had to make some we had to start somewhere right and

uh we knew we could vary the angle we could vary the angle and the speed or we decided we settled nicola was only here for six months so we had to settle on something that was doable uh because of his visa and uh and i said well let's set a vertical rate of ascent which you guys use all the time i'm sure and and we set a vertical rate of ascent that that mandy and and and nicola felt that we could have people sustain and uh and then we matched the vertical rate of ascent at different angles so of course it at five degrees you got to run pretty fast to do this vertical rate of ascent and at 30 degrees and 35 i think we went to 40 degrees in that study or close to it so steep yeah just to just to like a lot of people have forgotten high school geometry right now so the i'm gonna take a like a real a real world example that that a lot of listeners will will be familiar with and roger you probably are familiar with having uh lived in in the area for so long the back side of hope pass on the leadville trail 100 which is the hardest part of the course is about at a 10 degree angle and you are putting people not 30 degrees not 40 degrees 10 degrees and everybody thinks that's really steep and it is it absolutely is it absolutely is really steep and if you look at any other normal trail setting devil's thumb is probably like i'm gonna do the math

in my head right now probably about eight percent or something or sorry not eight percent eight degrees you're studying people on slopes that are far steeper than any normal north american i'm gonna caveat that any normal north american trail you go over to europe it's different because trails construction there is totally different but you're looking on things at this treadmill that it's it's almost hard to comprehend because especially for a north american trail runner because they just don't have that experience of actually actually how steep it is yeah yeah it if they're skiers that can help a little bit because uh i think a blue a blue run is sort of like 20 degrees ish and and a and a black diamond the double black diamond might be 30 degrees and and if you stand at the top of that on skis and you're not a really good skier it's like whoa it's it's yeah 30 30 degrees is tough okay so the the the origin from killian jornay starting or it's killing jornay having a uh having a lecture at the boulder running company and you attending it you guys started start to get into trail running the first question you answer is you want to study things that you want to stay locomotion at 30 degrees i'm going to fast forward a little bit through a few pieces of research and maybe we can kind of summarize it a little bit one of the things that has started to come out of the lab is this notion of running or locomotion economy is different at those steeper grades or steeper angles so we have

this like performance construct in in a marathon setting and this is why i mentioned this earlier where running economy is like this hero and you have published this uh most recently with a lot of the sub two hour research where one of the things that we are trying to optimize the most in a high performance setting is an athlete's running economy they're fairly tapped out on their vo2 max they're fairly tapped out on the fraction of their vo2 max that they can utilize throughout the course of the event we want to take all of these other different things that impact the cost of running or running economy and see if we can optimize performance in that in that way you can you can fill in the gaps of that piece because you're you're involved a lot in that pro in that project um but one of the things with that when we start to move onto the trails and steeper standards is this notion of running economy being like a hero metric to indicate performance is not quite as correlative and that's because the conditions are different so why don't we start to like go through that a little bit and what your lab has found out about running and or look and i'm using the word locomotion economy very carefully because i know that sometimes at the steep grades it's hard to say is the person actually running for sure so so yeah we we uh i was involved in the uh breaking two and and inios and and on a flat i mean almost exactly flat uh course uh running economy given those other physiological variables

are are pretty fixed uh running economy is something you can you can play with you can tweak you might be able to optimize get a little marginal gain on um and we assumed that that was the case for uh the vertical kilometer that that what we were trying to figure out was what what angle of the treadmill gives you this uh for a given vertical rate of ascent which requires the least amount of oxygen the least lowest slowest rate of oxygen consumption because um that means you could go a little faster if if that's an easy uh rate of oxygen consumption for you um and and that those data point towards 30 degrees being the the the the optimal angle if you want to maximize vertical ascent rate and that oxygen consumption is the limiting factor okay so that those are a couple of assumptions and and but i think it's pretty clear it's not an assumption in vk or everesting the goal is get the most vert uh in the shortest period of time and uh you know you have to sustain it you you can't be over your vo2 max can't be too far above threshold for too long right so um can i just stop you for one second yeah you just earned a whole lot of street cred with the listeners of this podcast by using the word vert uh right yeah so everybody now is like oh this guy he is a trail runner because he used the word

vert as opposed to some scientific jargon around it so i wanted to give you some kudos for that all right it's partly because i uh i talked to jackson brill uh uh maybe on a regular basis he's my uh he's my graduate student now okay continue roger that's fine so uh and i think jackson used this recently he he did in everest and he said uh he looked you know he had read our papers and and uh now he has his own papers but he said okay i should find the steepest steepest incline i can find if i want to uh get my everest in the shortest period of time so um but the the other the assumption is that oxygen is limiting in steep uphill bloke motion and then that's probably not true uh it's not the ultimate thing because or not the only thing i should say so um the the people who are hold the world record for the 10 000 meters on a track don't hold the world record for the vertical kilometer and vice versa the the the record holder for the vertical kilometer um is you know they're a fine runner uh but they're they're not running 26 minutes for for 10 000 meters on the flat they have specifically trained a pretty i i've um i'm trying to remember the swiss guy who's the uh he raises cows as well he milks cows uh he held the vk record for a while um as uh it's in my paper

uh anyhow maybe it'll come to me but but he trains specifically every day after he milks the cows he runs he lives in the mountains he runs up the mountain and then he runs down the mountain then he milks the cows you know at the middle of the day or whatever i think he milk cows twice a day and then he runs up the mountain again he doesn't do intervals he doesn't do uh he doesn't go to a you know a mondo track and do uh 200s he's very specifically training for for this and and that's because if you take a flat runner and you put them on a 30 degree incline they don't get out of breath first they say oh god my calves are killing me i i can't sustain this i i i'm i'm getting local fatigue and and that's what's going to make me stop or as we've done in a recent learned in a recent paper it may be the stimulus to switch to walking and that by walking you uh change the timing a little bit and you change this probably the uh the angles that the range of motion of the uh calf muscles um and so by our working hypothesis jackson's jackson burrell's working on this for for his master's thesis the the specific question of um whether we are whether we switch back and forth for walking and running in an optimal way but but anybody who experiences our treadmill or more fun out on a real trail that's super steep um is that you you're not necessarily out of breath when you switch to a

different gate it's it's not the oxygen uh delivery is not the only factor and um if the more the greater oxygen uptake you can sustain for sure that's going to improve your performance but if you know most of us it's hard to improve your maximal oxygen uptake but it is possible to improve your strength improve uh your flexibility uh and probably there's some evidence improving your connective tissue um through specific training for for uphills so uh i think that that's what these uh erv no it's urse zimmerman that was the guy who i saw the video of the cow the dairy farmer in uh in switzerland you know he he he's very specifically trained we when we did some of these 30 degrees studies we have contacts with a lot of uh people who can run under 30 for 30 minutes for a flat 10k and we'd bring them in and they they you know they were not it wasn't a piece of cake for them it was it was brand new and pretty hard for them to to do so they had there were but then we had mandy ortiz's mom i can't remember her name uh anita anita anita yeah she um she's she lives in outside of vale and and eagle county somewhere and and she runs a lot on steep uphills

and and she was doing much better on the uh on the super steep stuff than the the flat uh fast guys um you know some of them were from cu ncaa team um and and they could run some very good 10ks on the track but uh not up not up a steep thing so i think we talked earlier about how practical notes are important for your audience they're they're not going to go read not going to go write an article necessarily they do read articles but um uh boy the uphill stuff has emphasized to me how important specificity is it's it's it's such a weird activity that very few of us do on a regular basis um it it it's super important for a steep uphill yeah and so from a practical perspective as a coach here's what i took away when i saw that research if if i relate it to a marathon setting we think about specificity in terms of the bioenergetics and the speed so if you're going to go run a two-hour marathon two and a half hour marathon three-hour marathon you have to have the speed specificity to do that you have to train at those speeds and you have to have the bioenergetic specificity you have to train at those speeds and at that oxygen uptake essentially sure i think the what i took away from that is in the way that it influenced me in on the coaching side of it is the specificity

component of trail running running uphill and downhill and up different grades matters even more in that sport discipline and so when we shift training as we kind of go along the season as opposed to a marathoner who their training might not really even change all that much in the last eight or twelve weeks on the whole i mean you can you know okay we're doing 1200 meter repeats instead of 1000 meter repeats or something like that we think that that's a like a really marked change but from a trail running perspective i almost i'm going to use the word kind of double down to like make a gross comparison but almost double down on the specificity component where it actually becomes so big that you kind of you almost got your way from a training perspective to to get on those grades and to do everything that you can to train for the different uphills that you're going to encounter on race day yeah and and there are also some people make a big deal about running being a skill and and i can see different sides of that argument but um but for trail running there are absolutely specific skills that are not innate and uh so one of the things one of the limitations of our treadmill studies because we were measuring oxygen consumption is we couldn't we didn't people were unable to reach their knees with their hands um and still have the mouthpiece in because the mouthpiece was sort of fixed and uh that's something that that i do that's something

that lots of us do when you're on a steep hill is you you bring in accessory muscles your arms to push to extend your knees and and then i think you said nicola and you talked about the pole study and and that's that's just a more efficient tool to to use your to spread the effort out to your different arms but it's not easy right it's it's using using poles while running is is a is definitely a skill yeah and and that was a limitation of his study was finding enough people who were skilled at using poles on on uh uh i should say our study because we we we co i co-authored on that um my main contribution was correct converting uh italian english to american english but uh he's he's uh he's a great scientist and and uh and his english is excellent but uh not not it's not as easy for him to write as it is for me in english he was really he was really good and very gracious uh you should you should listen to it afterwards it just came out last last week as we're recording this um uh he was very nervous about his spoken english in in advance and it turned it turned out great but one of the things that we discussed in that that is that i think is really related to some of the things you're finding on the steep treadmill just in running in running uh scenarios and it's coupled with this notion that running economy or locomotion economy may not be as important in an uphill setting is there are conditions where it

is very steep and you're you're you're using poles where your economy is actually worse but you might actually perform better because of these other aspects that are going on yeah yeah that's that um i mean ideally and and on average nicola found that poles did improve the the economy but they were not running right they were they were walking so uh and and and it was really steep too it was he so i can't i can't remember uh so ours definitely our treadmill was for sure the steepest in the world for a while and then he built his and i think i think uh his is uh his definitely can go to 45 so i think we're we're sort of uh matched you know there's there's two that are equally steep uh and and and and you can't you really can't go you can't walk or run above 45 degrees it's it's just uh ridiculous so yeah even for us it's ridiculous well and that's one of the things i mean one of the blessings that you have in boulder there is you have a lot of really good athletes that can come in and they can actually try to run on these steeper grades whereas a mere mortal like myself or you it's like there's no chance even at the slowest of speeds or even yeah even at the slowest speeds we'd be we'd be walking yeah but let's get back to i i'm sorry i diverged it's fun talking with you but uh we want to convey some information to your listeners at least um

so optimizing economy is critical for a flat you know attempt at two hours or 2 15 for the marathon or whatever um absolutely critical um but and hold on hold on hold on let's like really quickly go over why that's so critical like why is optimizing economy in a road marathon because we hear about this all of the time like how important running economy is why is it so important in a road marathon setting okay so it's uh uh economy running economy is the rate of oxygen consumption that a person consumes at a specified running speed so let's make it iliad kipchoge it it for him to run at 21 kilometers an hour six meters a second um he let's say he uses uh 60 milliliters of oxygen per kilogram per minute right and that's the percent that's a percent of his vo2 max that he can sustain for two hours i'm a little off on my numbers because he's probably about 80 for max and 60s 80 but but you get the idea let's just use number 60 because it's a nice easy number so if um if we could do something for elliad so that he only required 59 milliliters of oxygen per kilogram per minute to run at that speed then he wouldn't still run at that speed he'd say oh i can go a little bit faster a certain you know 0.1 meters

per second faster and be at that sustainable 60 milliliters of oxygen per kilogram per minute so if you become more economical it allows you to run at the same effort but at a faster speed so that's why it's uh that's why it's so critical and in addition to that in a high performance setting especially at the marathon they're running at such a high percentage of their vo2 max there's nothing there's like you can only you know it's the estimates are anywhere between 85 and 90 percent of their vo2 max yeah there's nowhere else to go oxygen oxygen is at such a premium if you can reduce the cost of locomotion and like you said they're still going to run it 87 or 89 you just reduce the cost so right you or you maintain the cost but it allows you to go at a faster speed yeah exactly if that's your performance metric which it is in a flat marathon is how fast you can do it um then that's absolutely uh the the critical variable okay and i wanted to go over that because not once again not not a lot of uh of the lay audience will be very familiar with it but i i think that because it's become so important in marathon running we've automatically correlated it to ultra marathon and trail running and i don't think that correlation correlation and the data shows this is quite as tight and so that was going to be your next step so now you got the floor again

okay sure so i can't think of any situation for flat uh level marathon level marathoning where you would there's any advantage to doing something that worsens your running economy i just there's there just isn't anything uh the only extreme might be in temperature no even temperature it's going to be better to uh to be more economical because you'll produce less heat so um it's but let's there are situations on steep terrain or longer distances where you want it you could you you should probably sacrifice uh the running economy uh because it's not the limiting factor so if uh in a 800 meters after an 800 meters most of the runners are are bent over they're holding their knees they got their hands on their knees they're just like they're completely out of breath it's very clear that entered that the the rapid delivery of oxygen and and they're maxed out their uh their glycolytic uh and and uh uh so-called anaerobic system not so-called anaerobic systems are maxed out right um that's not the case when you get to the top of a of a really steep uh mountain uh if it's not at extreme elevation uh it's that's not that's not why you are are slowing down it's not that you're completely out of breath in every situation sometimes it's that your calves are

burning sometimes it's uh uh that your quads are burning it's it's it's not always the case um that that you're so much out of breath but you just don't have the the local uh the localized endurance of the muscles to do it and so that gets back to the pulse one of the ways to get around the local calf limitation or quad limitation is to use accessory muscles and it may take a little bit more oxygen it almost in many situations it does take more oxygen to use use your arms rather than your legs um but uh your legs are not burning out if you can if you can spread the effort out to a greater muscle mass uh that can that can enhance performance um and and we actually know from really kind of not boring but uh not at all athletic events in the laboratory is if we have a person ride a stationary bicycle that they pedal with their legs at 50 watts and then we give them a hand ergometer they use a lot more energy to to move the hand ergometer at the same power output so our arms are not as efficient at at doing uh doing work but um it it's a it's a it's been it can be beneficial to use poles because you spread the effort out uh to different muscles and it and it may be also what we know that it is um on steep terrain people

switch between a walk and a run at a certain speed and we know that one gate except for where they they cross over many times people are choosing to alternate between a walk and a run even though running uses more energy um on a steep incline up and for almost everybody who's listening to your podcast um up a really steep incline beyond about 15 degrees walking is going to use less oxygen okay but at the same at the same speed so um but we don't always and and if you watch a race watch a video of a race it's it's not that everybody is walking continuously but they're alternating between walking and running and uh that's because that that's a really nice uh magnifying glass on this question that you raised do you always optimize economy the answer is no in in situations like steep trail running steep probably it probably is true for running up the empire state building too uh steep uh steep locomotion you can you alternate gates triggered by local fatigue factors by by calf muscles is where our focus has been lately we think that it's the uh the calf muscles and so this question is going to be fascinating to a number of to aid the listeners but anybody who's just picking up this podcast for the

first time because they all have the experience of being in a race or being in their local training run and everybody's going uphill and half the people around them are walking and half are running but they're all going the same speed and they all have different respiration rates right so the heart rates are different the rate of respiration is different and i'm sure if we could take you know a magic magnifying glass and look at this localized fatigue that you were just mentioning especially at the calf that would look markedly different as well yeah yeah we've we've looked at it in the lab where we have people we set the speed we set the incline we put um uh electrodes on the skin surface above their muscles we measure what's called electromyography and uh and we can see that um there's a lot there are really some important differences between walking and running on steep incline and and one is that it's uh uh even though you don't leave the ground uh during steep uphill running it's still running it's bounce it's a bouncing movement okay and um i think everybody many of your listeners will know that when you run your step frequency is is faster and that's a pretty clear uh uh discreet change you know you're walk walk walk walk run run run run run run walk walk it it's it's not a gradual you don't gradually change your frequency when you change gates and and humans don't don't blur the gate they it's you you if you if we ask our subjects are you walk we say

would you please walk or would you please run they they they don't have any hesitation they they quickly switch they you know to a faster frequency when we ask them to run and um so so there are important differences and what that may do at the local fatigue level we don't have super good evidence or of this but um we'd like to um is it may affect blood flow so if you are uh running there's less time uh in between contractions of your calf muscles all right um and in uh and in walking there's a longer swing phase there's a longer time where your your your muscles are not active and that may be important for reducing uh or minimizing the fatigue the local fatigue is allowing the blood to uh reperfuse the muscle because when you're when you're sorry i used one of those uh twenty dollar words uh perfused means allow blood flow so if you are contracting your calf muscles in in your foot's on the ground in a run uh the blood's not getting to your muscle for that time when the muscle is contracted it's just not able to overcome the the physical pressure of the muscle contraction so the blood is kind of surging into your muscles when your foot's not on the ground and um

we uh i say we this is probably just me i think that uh an active a good area of research would be to look at blood flow the pulsatile nature of blood flow in in walking versus running um i don't really even know how to do that but there are things called doppler flow uh there there are devices that can measure blood flow in from the outside so let's hypothesize this for just one second okay so if part of the advantage of switching from a run to a walk is that the way that you're using the muscles is so markedly different and part of the way that that shows up as you mentioned your is your cadence so some of the practice that i see i don't necessarily agree with this but some of the practice that i see out with trail runners is they want to increase their walking step frequency to the extent that they're trying to match or get as close to their run step frequency as possible because that's the form of locomotion that they're the most used to and when i look at that and knowing this this localized fatigue phenomenon that's happening that might be alleviated by switching between those two modalities i say no i actually want it to be different i don't want to try to contrive the walking modality to be close to the running modality because there's something within switching between walking and

running that is beneficial to performance that's a total hypothesis that i've had just coming up with the research but what so what do you think about it having been a part of all this yeah that's uh we have not done that experiment it would uh uh well maybe i can't say we but uh she she turned out to be my PhD student but a woman named uh chris christine snyder was a master student uh here at colorado with my uh my wife claire farley and they did a study of uh uphill running uh really modest inclines by the standards we've been talking about today um but they had people run at different frequencies on an incline and just like we do on the level people chose and found their uh energetically optimal stride frequency in running um i don't know of anybody who's done that it's been done for walking as well on the level um and on the level people choose uh they find their optimal step frequency for walking and so i don't think it's a pretty small uh uh logical step to think that that's also going to be the case for uphill walking and that um i think that may be a that may be a not a good good way to spend your training time uh that would be my guess you may be able to switch the optimum right to a faster frequency the body may adapt to that but i don't think that it's going to be a lower

optimum it's not going to be a it's not going to save energy um that i said i mentioned earlier well you mentioned earlier that i've studied a lot of animals and um and i just recently i said that in i specified in humans and and that is that humans use discrete gates and don't blur them very much um and and that's true of in most situations for animals but we we found uh my wife uh claire farley was a scientist uh we we met in the lab and so on anyhow she's done a lot of locomotion experiments back in the you know but not for the last 15 years because she had health problems but anyhow claire um we were interested in why horses and why and dogs why four-legged animals switch between gates and the first thing we did was we put a little weight vest on the on the dogs and um what the dogs did was they we used the word slur they kind of they blurred the gate distinction they they they they continued to trot but it was not like the way they were trotting without the weights yeah the horses the ponies when we put weights on them they immediately uh switched to a gallop and spread the force out over uh more legs uh at a time um but uh but the horses i don't know i don't know whether it's all training and selection or what but horses are very discrete they choose it's either

this gate or that gate this gate or that gate there's no in between but dogs and i suspect some other four-legged animals perhaps smaller four-legged animals um blur that gate distinction and it and it may be for a good reason um i don't know um and it may be trainable you know if if you take your dog backpacking sometimes people can't have the dog carry uh some extra load um and they may adapt to it um but boy i don't think i don't i can't see the advantage of uh i can see a disadvantage of using a high step frequency in walking and that is that um when you're when you're walking your leg is relatively straight and advancing it swinging that leg forward um that internal work to swing your leg forward is going to go up dramatically if you increase the the frequency so uh boy i'd be very surprised if that was advantageous yeah i keep coming back to this strategy uh and i used to be a form wonk you know in my early coaching days where we'd look at you know slow motion you know tapes and try to yeah you know okay let's try to optimize your foot placement and all this other stuff and a lot of that is my track and field background like working with sprints and jumps and hurdles and stuff like that where that type of technique is actually really really valuable but i keep coming back to you in a in a running situation i don't try to change much unless it's really egregious um i just don't i don't even mess with it because you know there's always that there's always that

period that they're worse we know that much whether or not they can get better i it just don't it's it's not consistent i guess is what i'm saying it's like sometimes they get worse and they stay worse sometimes they get worse and they might get a little bit better yeah i i have a very well-equipped laboratory still and and yet the sensors that uh we have in our body are are substantially better than the and the processing power that we have for those sensors are is still substantially better than than uh what we have technologically but but let's go back to this person or or this uh these people who are training for uh high step frequency and walking i think they may be on something and that is that runners don't train for walking very much yeah and and uh that's makes a lot of sense if you're uh iliad kipchoge or uh galen rupp or somebody who wants to run a 10 000 meters or a marathon at which is at a crazy fast pace but um but if you know that you're going to do a 100k or 100 mile or or whatever or a very steep even a you know a 15k that's got a lot of steep terrain um it seems like we should be going out for a walk rather than going out say we're going out for a run i mean you could still say to your friend oh yeah i'm going running but don't run right go go to a steep uh a steep hill

and and and train that walking it comes back um you know i i can't help but be a professor even though i'm retired right and and the biggest thing i did the same thing when i was a student but the biggest mistake that students do is they study what they already know they have a test coming up and they're like oh well this is i like this stuff i'm going to study this stuff and it's like you already know that stuff what you should be studying and working on is your weakness and athletes don't we're we we do the same thing right we say like oh i really like long gradual runs in the forest i i hate going and doing intervals and and yet that may be that working on your weakness is um is probably the smartest use of your training time uh it's where there's the there's the most potential for gains and uh and yet very few people train for for uphill walking for steep uphill walking and yet that's that's you get the time that you can gain on the uphills uh is is huge compared to the time that you can gain on the on the level or even even more so the downhill but i i think downhill training is is a specificity of downhill training is uh is super important we haven't we haven't done much on downhill running in my lab i have to admit well and the the uphill uh component of it or the walking component of it i always have a hard time uh getting getting

buy-in with athletes on that because they think it's too easy but what i what i do is i just show them how much they're going to be walking during a particular race and most of the time they're absolutely flabbergasted it's on the order of five or even 20 fold what they thought and the exercise that i take them through i'm like okay how much you think you're going to be walking during whatever leadville trail 100 western states whatever and they say uh maybe an hour or something like that and then it ends up being like 8 or 10 or 12 depending upon the speed hours they're they're completely wrong and so that's the first step that i take in fact one of the things that i'm trying to organize right now maybe i can cajole some enterprising master student out there to help me out with this is to see how much running and walking there is across different finisher times for some of these major ultra marathoners i have that data set in my you know in my wheelhouse because it's something that i that i track a lot but i don't have it outside so i can't you know i can it's my own n of one yeah but most people when i go through that exercise with them are just absolutely stunned at how much walking they're actually doing particularly at the at the hundred mile distance and then we translate it into training because i you know you and i've gone through this before with the previous edition of the book i view it as different almost different sports right they're connected by the cardiovascular system but the way that the human moves through the trail is markedly different yeah it it's you

monitor the gate with uh from cadence so you can you can yeah i just take it no i think that's a perfectly good uh in fact it it may be yeah that's what uh jackson and i are using for his master's thesis where we're not using a a wrist we're using a uh an inertial measurement unit at the at the hip um at the waist and i think that might be a little bit better but it gets it close enough like of course you don't have all the data but if you just draw a line you know like okay everything above here is right and i actually have a piece of software that'll do that for me i can say everything above here is running and everything below here is walking and in all i cannot i can't throughout my entire coaching career i've never had one situation where an athlete walked too much in training we'll use the word power hike because that's what trail runners like as opposed to walking where they have done that too much in training and yet everybody does it does running too much in training yeah yeah it's it's uh yeah if i think the math is a good way to do it because if you could improve uh if you could reduce their walking time uh their their speed during the walking phase by 10 or five percent it's it's a huge number of minutes right and and yet uh you know imagine a triathlete it's it's almost it's almost like a triathlon right you could you imagine a triathlete who didn't train for swimming uh would be would do

terribly yeah right they'd give up so much time in the swim um and and an ultra an ultra see we can't call it an ultra power hike but an ultra marathon an ultra an ultra locomotion uh is is the same thing if you don't train for the walking part it's as dumb as not training for swimming in a triathlon yeah 100 okay we we we digress there a whole heck of a lot which is which is totally fine and really and really fun okay so you've now passed on the lab and the tools contained within the lab to another fine group of individuals and kind of with your the legacy that you have largely uh created there they're they're in very good hands i know there's a zillion things in your head of problems that you want to solve and you only have we all only have a limited amount of time on this earth what do you think the the steep treadmill where do you want it to go in the next few years like what problems can we solve that are specific to trail and ultra runners there uh literally it's going to go to the university of massachusetts so uh i'm going to give it to my former postdoc valter hoekhammer who has done a lot of we've collaborated on a lot of running studies in recent years and he's just starting as an assistant professor so uh that's where it's uh physically going to go i think that we have some other i was talking earlier about how tools are important and um and we have emerging better and better tools for studying local fatigue so um one of these your

you you and your readers or your listeners may be familiar with is uh is uh infrared uh uh mers uh infrared spectrum intra infrared spectrum spectrum spectrometry uh anyhow i'm glad you got tied up at least once because i do that a dozen times on these things so um uh i think these mirror sensors are i know they're getting better i just saw a paper by a physiologist uh uh who i really respect michael joiner his group um is using these to uh to estimate blood flow and and to measure oxygenation of uh local uh in local muscles and um we've also so that's a that's a really important tool that that is going to expand the other tool that um i saw i saw probably in uh like 1995 was uh ultrasound uh small sensors that can go on the muscles and measure the actual length change of the muscle fibers during an activity and um those work remarkably well for superficial muscles like the ones that are most critical here the the gastrocnemius and the soleus is the are the key muscles and where this this technique works really well um so understanding what the muscle fibers are doing in the different gates um those are two tools a third tool we've used conventional electromyography emg which involves putting two relatively big electrodes kind of like

heart rate electrodes on the muscle on the skin over the top of the muscle and that's probably um equivalent to going out uh you know in a shopping mall and saying asking two people who they're going to vote for and and can conclude that uh there that's that's a good survey right and it's it's and so we know this we know that electromycom conventional electromyography has not been it doesn't tell us everything that we want to know and um there are grid electrodes now my colleague roger anoka has adopted these uh wholeheartedly and it and it instead of just having two electrodes over the skin over a muscle he'll have a you know a hundred electrodes and be able to uh to get a much more representative picture of what the muscle fibers are what the activity of the muscle fibers are so so i think those are new tools that will be uh will be really helpful but what you i think that the common thing the common theme between all of those is is it's a more intimate view of what's going on at the neuromuscular level muscular and or neuromuscular level right and and and it's localized yeah because uh that that's the um that's that's i think that's where there's a lot of action um but the second thing that we haven't done uh that i'd like to i would have liked to i don't know maybe i'll get to collaborate with some with valter on this is um is the trainability of uphill economy

so we there is not very there's weak evidence and and mostly evidence to the counter that you can a person can improve their running economy on level ground by a substantial amount okay there the best counter example is paula radcliffe and and andrew jones in the uk studied paula radcliffe from uh i believe she was like 16 until 35 or something like that and she did improve her running economy over that long period of time and and i think that's probably true um based on our we've studied really older people people over 65 and their running economy is not is not worse if they've been lifelong runners they're running economy uh and there's every reason to think that it should be worse but it's not so i think that it's probably it is getting worse but it's getting better at the same time so it looks the same right it's it's the aging process is not pretty but um but running economy stays about constant so so that's what i was saying about level i don't think there's a it's not easy to change your running economy on the level by a substantial amount there's some marginal gains but we know that these people like urs zimmerman and other vertical kilometer specialists uh it's not that they have the highest vo2 max in the world and it it certainly is something that they have very specifically trained

their their muscles for uphill locomotion but their end result may be that they are more economical uh at the specific skill of of running up steep hills um we didn't find that at more uh my uh grad school roommate tim briner and i and i published a paper 25 i think it was 25 i remember 30 30 years after the data were collected and we had both retired uh and we published his his master's thesis data and that showed that uh if you take an average uh you know recreational runner who runs uphill downhill level just without specifically thinking about it um it's not that there are people who are specifically economical downhill runners or specifically economical uphill runners but i think that if you take if you if we looked at some people either it'd be easier to do as a cross-sectional just to look at first and that is to get some really elite vertical kilometer athletes and see what their running economy is on steep inclines and i bet that it's i bet that it's better um and uh and then the follow-up study would be to uh take someone who's who you're converting from a level runner to a mountain runner and and monitor their uh their uphill economy over over a training year uh at least a year and see if uh

maybe maybe you could do it more intensively you might be able to do it in in eight weeks just if they were focused on improving their uh uphill running economy so what would your hypothesis be that it's more trained well i mean probably be more trainable in the flat condition if you're saying the flat condition isn't trainable at all or it could go down i guess yeah um i don't think we have a great explanation for it but there's pretty strong evidence from a number of groups now that plyometric training can improve run a level running economy and um i would say that although we typically think plyometric is jumping off of a box and uh down and back up um i think that probably uphill running is is a pretty similar to a plyometric uh kind of training um because you are still bouncing um and and that so i think that the strength um the the muscle fibers are adapting to uh operating at the at an optimal length um and the connective tissue may be adapting as well um i i i can't really it's hard to get too far along speculating on the mechanism but i think i think it's worth i think that would be i would pursue that that would be if i was a master student out there listening to this uh podcast um that that's that's a worthwhile uh endeavor looking at the trainability of a very specific locomotor task a novel right uh locomotor task the the hard thing you always have

with those types of studies is the novelty of it right because you have to find enough subjects where that locomotor task is not novel such that the trainability kind of fuddles with whatever else you're measuring so maybe maybe uh i shouldn't i'm sure i suspect that valter hoekammer will listen to this at some point and uh valter uh valter's from he was born in the netherlands and i think that might be what you should do is is uh take a group of people who train in the netherlands where there's zero hills except for the bridges over the canals and and take them to the uh french alps for eight weeks and and and run hills uh or maybe even in belgium you could go to the arden there are some hills there but um i think and you may even be able to train them on a treadmill i mean i don't think that's uh that that that would be quite reasonable the the advantage of a treadmill for steep uphill running is that you don't have to run downhill yeah and so if you're trying to not injure someone um you know but but then again you can't if you're going to run downhill in a race you have to train downhill or else you're going to get hurt in the as in the course of the race so yeah but um yeah i think you would want to i think you're right to stack the deck you want to get people who hardly ever run up a hill and uh the the study that tim briner and i did that tim did that i helped him right up uh

uh was in central pennsylvania which is is about as mixed as you can get there's there's it's not up it's not really mountainous yeah but it's not flat it's it's just rolling hills basically yeah and so people those people were uh perhaps the most generalist you know they they they were used to some uphill running but not extremes and and but they weren't solo flat runners solely flat runners yeah my my speculation on that is and this is pure speculation i can make pure speculation because i'm not a scientist and i can be wrong and i can be like you know we're wrong all the time but uh my my speculation on the adaptation part of that is that it's very rapid meaning if you took a runner from the netherlands and you brought them over the alps and you saw how their economy and or their performance and uphill conditions changed my my hypothesis would be it would be kind of like an asymptotic curve right where where it improved very quickly early on and then sort of leveled off the what where i'm coming to that from or the rationale the mechanistic rationale behind that is that the initial uh the the the initial driving force behind those adaptations are neuromuscular and we know that those adaptations are relatively quick to happen as opposed to the cardiovascular ones like all the stuff that we talk about in typical endurance physiology those take months and

sometimes years to to to pull off and we see it a little bit in practice where we take runners that are from like the midwest or they don't have a lot of elevation gain or elevation loss and then we do a training camp with them in the sierras or in the rockies or whatever and they get markedly better after just one or two weeks and they're able to handle the elevation gain and elevation loss of whatever particular race yeah you're probably right uh everything is uh diminishing returns in training right you get you get the big bang right away 100 100 all right this is fun i really appreciate it we're gonna let you go um i don't have any normally ask people like where can they follow you but i feel like you just want to go off into the mountains and go run and hike and things like that oh uh well i yeah they they uh i'm on twitter um but it's uh not a tremendously high percentage of science on twitter it's more uh sarcastic comments about uh world events and uh things but uh uh whenever we publish a paper a new paper i always put it up on twitter so maybe that's worthwhile they people would have to put up with my uh other comments so yeah people are used to that now you did have a few good zingers though uh during nike's breaking two project and the inos 159 project i give you total credit for

for those code out because that did not come without controversy that's not something that we talked about in this podcast but i know that it was something that caused any gray hairs that you had left to become great yeah yeah i i have uh stuck my finger in the electrical socket on a couple of issues in in recent decades so the oscar pastorius was uh was one of those and uh and the the vaporfly shoes was the second and and then two hour marathon was a was a third but uh um i've been lucky enough to to be at the right place on those and and uh you know they're they they are in my opinion historic uh points in the in the history of running so uh and and certainly history of running science so i've been lucky to be at those those uh crossroads that's a perfect way to bring it full circle roger because one of the more influential uh pieces of impact that you've had on me is when you brought a lot of the stuff from the oscar pastorius trial into the undergraduate class of yours that i attended and i knew at the time because i was an older undergraduate student that that would not that that could have come with a little bit of controversy because of where it was at the state but i appreciated it as a student and as a lover of history of track and field sports that you were able to do that and so i would encourage you and other scientists out there to keep sticking your fingers in electrical

sockets because it's entertaining it brings people to the table and ultimately if it makes people think it's going to make our understanding of everything better yeah it it really sometimes these things really focus our thinking absolutely all right that's a good place to leave it thanks roger appreciate it bye jason all right folks there you have it there you go much thanks to roger for coming on the podcast today hope everybody got something out of that particular podcast to better meter your uphill efforts thank you to all the listeners out there i appreciate the heck out of each and every one of you and if you think that you are a good candidate for coaching you want to raise your game up another level for any of your summer endeavors go ahead hit me up on social media i would love to connect you with one of our coaches or maybe i'm the right coach for you and i'll coach you myself information on all of that is in the show notes as well as information on some of the more recent research that roger roger has recently produced that's it for today folks as always we will see you out on the trails you