#85- Training load and running-related injuries with Dr Rasmus Østergaard Nielsen

hello and welcome to inside exercise I'm Emeritus Professor Glenn McConnell from Victoria University in Australia the idea behind inside exercise is to bring to you the absolute who's who of exercise research so exercise physiology exercise metabolism and exercise in health and one I'm really wanting is for you to get your exercise information from the research experts rather than from influencers and indeed today I'll BR to associate professor Rasmus Tigo neelson from arus University in Denmark he's an expert on running related injuries he really focuses on the importance of training load in terms of running injuries

so Runners tend to think about their training load and how many kilometers per week they do but what about the distribution of that training load so if you're doing 50 kilometers a week it makes a difference if you're doing you know 10 kilometers 5 days a week versus 25 kilometers twice a week and what about the intensity so the training uh intensity the training distance but also we discussed a lot about what about the training surface what about the shoes so the importance of making very gradual changes we even talked about you know the non-training

related um stresses so you know he talked about if you've just spent a week painting the house but you're still running the same you might say well I just got injured and I didn't change anything but you did you would just spent a week up a ladder uh and then you were still running the same so I found that really interesting and it made a lot of sense to me we also talked a bit about running shoes and it's interesting to sort of compare and contrast what we discussed in the previous podcast with um Professor

Irene Davis and what I discussed with rasmas I think it's important to watch both podcasts to get a bit a more complete understanding of running injuries and the factors that play a role in them and also I'll have a third podcast coming up talking about running injuries I found it really interesting I think you will too so stick around now if you'd like to do me a favor and also increase the awareness of inside exercise please like subscribe leave comments Etc because then when people do a search they'll be more likely to be suggested that

they watch inside exercise also you will see down in the notes that there are time stamps so if you're on YouTube you can go down there and click on the times it'll move to that section or on the other platforms you can just look at the time and move there there yourself but as I always say you'll get a lot more from watching the whole uh podcast episode you'll get more context Etc okay so enjoy the podcast with Rosas hi Rosas welcome to inside exercise thanks for coming on how are you doing right Glen thank

you for having me yeah my pleasure so people will see hopefully that the last uh podcast I put up was also on running injuries so having a bit of a series here so your number two out of three well who knows there might be another one but there's going to be a few at least on running injuries uh talking about shoes and effective load and and all sorts of things what I thought we could do before we talk about how you got under research and things is maybe just to say how yours is maybe a

bit maybe different Focus for example to Irene Davis who people might might have a look at which is the one prior to yours yeah yeah certainly and and my acknowledgement for inviting different uh persons with different viewpoints on running IND into these podcast series uh and I really with with enthusiasm listen to the podcast you had with Irene uh and and and Irene really at least in the clinic works really much with the really injured Runners maybe those that have been injured for for many years uh and should be treated as such uh where where

they they may need some gate retraining or or alignment uh adaptations in order to successfully return to running uh whereas uh this podcast from from my perspective will be much more focused on injury prevention so how we try to keep the uh Runners running without any injuries uh so so that that's a slightly different perspective I think I'll I'll put into this uh so so I like the theories put into perspective for byin uh on on the the really injured uh group and how to treat them uh appropriately and and now we we switch the

focus in this podcast towards uh ethology courses uh and and prevention uh in a train load and shoes perspective yes yes so it's good to point that out and to be honest I didn't actually pick up on that with when I was talking to Irene because I was I guess we never already talked about some of the things I want to talk to you about which is you know are we talking about uh people that just run casually here and there or recreationally trained or serious or Elite or whatever I guess we didn't really go

into that with Irene so your feeling is the there sort of gate retraining and and um thinking about know trying Minimalist Shoes and things like that you think that's more appropriate for people that have had years of of injuries or or or do you or would you suggest that even for people starting out maybe you could be there I would say for the majority I would say training load is is for me the most important uh Focus area uh amongst those novices recreationals and also Elite Runners um in order to appropriately uh adapt to the

load that you're exposing your body to you must really pay attention to what you do uh in the training scheduling uh and and the changes you make over time uh because for me uh many courses are based on a training load error uh so you you do something differently uh in your training uh and if you do too much uh then the body will will react and and maybe you have have an injury uh whereas if you run the same as you been used to to uh over and over the years then the the I

believe at least the uh chances of having an injury because of doing the same again again again is really Slim uh so I think you need to do something differently in order to sustain an injury uh and and and that's the different perspective here uh that it's not you know the alignment and and um gate retraining theories it's more like focused on the load how much do you different structures in the body uh at times okay well that makes sense so if you change something you haven't had time to adapt to it you're more likely

to get injured for example yeah okay so so we we talk us as an example Glenn when we sit here and maybe the listeners out there sit sitting on a bike or they they they know sit on in the couch or in the car listening to this uh May reflect I am I able to sustain a running injury while sitting in a chair of course not you need to run in order to sustain an injury uh so it's a matter of how much you able to run before you sustain an injury uh under given circumstances

of course uh so so the the underlying fundament at least for me is is uh with the overuse related injuries are that that we need really to consider the training load as a necessary component in the Cal puzzle underneath uh injury development uh because if you don't consider the training load then then we are not dealing with the cses necessarily yep yep all right so we'll talk about that which which is which is it was quite interesting because when I started talking with Irene I was going to talk about all these sorts of things but

then it became more um how we haven't evolved to wearing shoes and and um you know things like that so it became uh focused on shoes I found it really interesting think it's you know really uh worthwhile people listening to that in in you know alongside yours but U maybe we'll get to that later you know so we're talk about you know should people have Minimalist Shoes and and fat shoes and what differences are make and things like that but we we'll start off as say sort of talking about what causes injuries the effect of

load and you know incidents of injuries and all things like that but I wonder if I could get into I I kind of looking at you and thinking maybe you're a runner so I'm wondering wondering how did you get into were you like an athlete first and then you decided to research or you a researcher or I think you maybe you're a runner first uh first I was uh a gamer as a teenager I didn't I didn't do any running any physical activity at all uh so so from I know 13 to 18 I I

didn't do anything at all I ate pizzas and drank a lot of cola and and became really huge um and and then I was forced to go to the Army in Denmark you need to to pick a number and I drew a really low number and I was forced to go and of course that that's I need to change my lifestyle to be become more physically active but then I was completed with the Army and then I I took up the old lifestyle with all the gaming in and the pizzas uh but then suddenly a

friend of mine asked me to go to a road race a local road race and and I actually finished last in that road race last wow I don't really mind how I look but but uh finishing last that that that really wasn't too good so so from that time I decided I I need to change my life now and and I did and I love running uh and I did ever since so I decided when I finished last that someday I I will win this race and I did seven years later no last first so

yes and that was a good feeling so so now I'm still a runner I run nearly every day uh still love to compete uh I'm not good I've never been an elite Runner just for creational purposes but but still I compete against won that race though you won that race how did you that race course but that was to to compete against others it was to compete against myself basically and I think find that very fun and and and motivating driver and I also love to go out having a long run and and a conversation

with uh friends and colleagues uh running mates uh so so I do that a lot actually great I'm glad glad I asked because I had that totally wrong I was assuming you got into running injuries because you're run out forever and all that so it's it's a really good it's actually more interesting story right that you've you turned yourself around and uh and the people can do that I also got all the injuries and then I thought okay this is annoying and this is uh inappropriate and and demotivating and then I thought okay I want

to study these injuries so so I I signed up for physiotherapy uh bachelors in in Physiotherapy and and I from the start knew I was going to work with running um and I thought really now I'm the right place I'm going to learn a lot about running during these next three and a half years uh but I really didn't and I want to do my bachelor's uh in in courses of running um and I was told you not allowed to because that's not within the scope of Physiotherapy and I said what that that's that doesn't

seem to to to match uh physiotherapy is also about running and sports injuries so I was allowed to do that uh and and it was it was good because then I was allowed afterwards to to to jump into some some some research uh in a my spare time so I worked uh in a orthopedic clinic dealing with sports injuries on a diagnostic level and then I had a company of my own where I looked at indu Runners for for a number of years so I worked in clinical practice after graduating as as pisio for five

years um and then I saw all these stories and all these these you know I think I could put things into certain boxes uh based on their their stories uh and then that that made me go into research uh because I also worked in a running shoe store for for seven years selling shoes oh wow with with with all these you know uh recommendations that we needed to give uh and I challenged them a little bit uh and that was also a driver for my research that that uh can this be true the way that

we actually recommend Runners to to pick certain shoes based on their alignment and uh shouldn't it be more based on training loads but I was very very much in the beginning focused on alignment my my bachelor dissertation was about coures of running with a focus on pronation because I believed at that time that pration was the most important thing because that was what I was told um both in in in this the literature but also in in the the clinical and and running shoe shop setting studing and say see you have you had you have

got a roundabout way and a very interesting way of getting there so you were actually interested in running and then you got into research but you weren't by and you work in a few shop so it's very interesting how you got there yeah I I became a runner and then I worked in a sh shop uh so it was in my teenage years that I I I was a gamer and and nonactive person um but but after that I was really engaged into running because I I loved it um and uh then I did my

masters also about running um and then I was lucky enough to get a fully financed scholarship for PhD also in running uh and after that a post dog in running so yeah all my career has been focused on running uh but it was a a decision from the start that this is a cool uh uh way to be and and I would like to make running my career and and I did and I'm still working on it and and I fully enjoy it every day think it's fun and it sounds good that it sounds like

even not even but when you're working in the Running Shop you were questioning things so you had that sort of researchers mindset kind of from the start I'm annoying type I asked question I'm think I'm a person are very you know I I want to do things properly and I I really want to do things uh correctly uh and I if if I can't make things match as as i' believe they should be matched then then I start asking questions uh it can be good or bad I close some doors at times for myself uh

but but also I I I think it's fun to uh you know getting into a dialogue and and having a debate about things uh and that's also why now I've decided I'm I'm 100% employed based on uh public money uh as a researcher an associate professor so I do not have any company uh besides that I do not have any conflict of interest I do not receive any gift or royalties or all these things so I really try to to be as as you know uh transparent uh and and trustworthy as I can as a

researcher uh because I'm I'm receiving public money to do you know trustworthy research so I I really take that task seriously ex all right so what I was going to talk about pronation and things later but seeing is you um Irene bought it up and you bought it up that that and I saw uh some of a paper or two of yours that you find that the neutral shoes you have you know no greater or lesser injury rate than these shoes that try and reduce pration so do you want to just talk about about that

a little bit and and you said the literature did did suggest that um you know excessive pronation was a problem but did you want to just flish that out maybe even just remind people what pronation is and superation and all that yeah yeah pronation is the F rolling inwards uh and and um like 15 20 years ago it it was really a strong argument in the shoe shops that that pronation was was bad and and you would sustain an injury if you have had excessive pronation uh so all those that were pronators were recommended to

have motion control shoes uh and uh and and at that time it was said that it was evidence-based um and and a lot of uh legure was based on Expert opinions where orthopedic surgeons and others uh recommended everyone not to have excessive pronation but um there was no prospective Court studies showing that it was actually more injurious uh to run in a neutral shoe as a pronator compared to uh running in a motion control shoe as a pronator and I found that that interesting that that it the claims were really not supported uh so so

I did a study where I took novice Runners and put them into um neutral shoes uh and and investigated if there were injury uh differen in in the injury rates between those that were pronators and and those that were neutral feeds uh and it turned out that that the IND rate were were similar and and and that was as expected I actually expected to find that but it was really blown out heavily in in in the mass media at that time it was in in 2014 um and since that time uh especially the the group

from Luxemburg has has done a lot of studies on on running shoes and and running injuries uh with with different findings and and from my perspective at least what they find uh um may show that actually changes in shoe type may lead to to an an increased risk of injury because they actually find that that those uh Runners that pronate uh and they they they recruited recreational Runners so the recreational Runners that were assigned randomly to a neutral shoe had more injuries than the pro the prona runners that were assigned to the motion control shoe

so that really confirmed the shoe sh Fury that we should you know recommend pronators to have this motion control shoe but but what I believe may have happened in that study was that the the recreational Runners that were pronators already had the motion control shoe from the start so they were running in that and then they suddenly switch to the neutral and then then change their their load distribution and and by that I think it's it's a shoe change issue rather than it's you know a shoe type issue here so so I think the literature

currently and we also did a study where we saw if people suddenly changed their shoe the injury risk was higher just immediately after they did you change the transition is is is the key here so it's not you know protion is dangerous it's not that super Nation that's going outwards is dangerous it's not about standing neutral is is dangerous I think it's it's dangerous to run too much um and and uh you can do that in a lot of different ways and and that's what I I really hope to to get get across in this

podcast all right so so you're saying if if everyone just started off and neutral shoes so you're saying it's the changing the shoe you think is the problem too quickly so if if you you want to change from a shoe that's that's kind of what what do you call it foot control or something the ones that motion control motion controls the ones that are trying to prevent excess so-called excess pronation um if you need to do that slowly or you might get injured so it's not it's not it's not the neutral shoe that causes the

problem it's the fact that you were used to running in a shoe that could have stop your pronation but are you saying that if everyone just started off on a neutral shoe um from the start you feel like there'd be no difference and injuries in the ones that have so-called excess pration versus the ones that don't you think you think you don't need to stop that what our data suggests uh based on the studies that we did yeah all right so so would you suggest based on that so again so if just someone say someone's

been running along with the the motion control shoes for years and years and years and they haven't been getting injured for example would you say well hey it's not broken so don't broke it's not broken don't fix it would you just say keep doing that or would you would you suggest that everyone should probably get slowly change into a neutral shoe because that's probably the way we've evolved or something no no no I think if it ain't broke don't fix it so if you are um adapted to motion control shoe have been been running successfully

in that for a number of years why change that if if if you are running what what you would like to and and if you enjoy it uh then we can always discuss um you know uh performance enhanc M and and all these things because that that that's the weight of the shoe and and and the lower the weight of the shoe is the faster you run and then you take out all the motion control and and and then You' run in a neutral shoe basically uh if you want to go fast but but if

you just want to do recreational running and you want to out socializing uh enjoying yourself get get a break from the family obligations or whatever and and you don't consider performance enhancement then just continue in in the that that that you love and and and that works for you so yeah if it ain't broke then fix it okay all right so I know you did a lot of research on the incidents of you know uh back in 2015 but you also had one just this year running related injuries among more than 7,000 runners in 87

different countries so what are the running related injuries what are the rates and I guess does it make a difference if you run a lot versus not much or what the data showing yeah a lot of Runners sustain injuries uh and and how depending on how we Define injuries it can be defined in in slightly different ways uh but if it's time loss based so you need to have a break for running or or at least you need to reduce your your running load then then our data suggest that around 50% of of Runners sustain

uh at least one injury uh over 1,000 kilom so if you run uh over one year or over two years 1,000 kilm the risk will will be around 50% uh and then we have studies on injury rates uh where we see that that novice Runners sustain more injuries than than recreational Runners and and more experienced Runners so so the novices sustain 17 injuries per thousand hours of running whereas the danger rate is is is significantly lower amongst those that are recreational Runners and and dragon Field Runners Elite Runners um if we compare on a weekly

basis for instance so how many injuries do no is sustained on a weekly basis compared to recreational Runners then the injury um risk will be the same because uh the recreational runners run more than the nervous Runners um so so depending on how we look at it uh different numbers but but conclusively yeah the injury risk is high it's probably a funny one to look at isn't it because if you're not doing much at all because you you've already touched on it I know you you're itching to talk about training load and all that and

injuries and we will get there but I guess if you're not running much at all your point kind of earlier was you haven't had time to adapt right so if you haven't run much at all you're probably going to an engine because you're not you haven't adapted yes ex and if you run sort of like in the middle it's probably like a lot of things like if you do nothing it's not good if you do tons it's not good but kind of in The Sweet Spot where you're running enough to be adapted to it and

you're not going crazy you probably don't get injured is that is that fair to say uh yeah along those lines yes uh I also think that that those running a lot uh actually can tolerate a lot so it's it's about if they suddenly do something differently um um but but yeah I see a high injury risk amongst the novices uh either because they put on too much load too soon because then they suddenly get Mo gets motivated and runs five times a week and and they're really not adapted to that not ad or they they

do not run at all for one month and then they suddenly run you know a half marathon or something and and then certainly they're not adapted to that either but that's the usual stories we we hear in the clinic when they come in and and tell what happened oh I I didn't run and then I ran a half marathon and okay that that that makes sense that makes sense exactly all right so just while we're talking about that because we're gonna get to the thing like a how much should you increase your load you know

and people used to say 10% per week and people say 5% per week but naturally if seeing as we're talking about office Runners um again it's going to depend how much you're doing right so if you're running 100 miles a week or 100ks a week or whatever increase by 10% a week that is just huge yeah if you're doing like you know 10ks per week and you go up to 11 that's not huge what do you think about that yeah yeah you're true it's correct that um the relative increase by 10% um can be seen

differently dependent on where you are because if you run let's say one kilometer uh per week then then 10% increase is is not that much MH or is it it depends on who you are I think because if you are a person with with a lot of previous injuries and you have a lot of additional weight then 10% to one kilometer may be sufficient uh if if you have a young person without any previous history of injuries uh have have have some experience from other sports then a 10% increase from from one kilometer is is

is too too little and demotivating so it really depends I think on on the athlete we we are we are dealing with um and and and also what what exactly constitute these 10% uh so so how do we calculate it and and and what what are the the underlying fundament when when we discussed this this 10% it's also interesting um that's true because and you can't just put 10% on continuously over a year because then you suddenly need to run after that year maybe two or 3,000 kilometers per week exactly wouldn't recommend that exactly and

as you're saying as well we're tending to sort of think oh I am any way of just distance but but that's not the only thing you you you altering you could be you could be doing the same distance but but all of it Intense or all of it easy or something so so why don't we that you cut loose on your um your you know effec of trading training load on injury so what are all the factors there that that are going in there into that yeah yeah the way I see it is is first

I separate injuries into either um overload injuries the traumatic ones um where you yeah step into a hole while running and and and you you sustain an ankle injury or something and or you get get hit by a bicycle and and and you get a stress you get a fracture or you know the these injuries I won't deal with those because that that's that's on a traumatic basis uh so now go into the uh overuse related injuries and and the interesting aspect amongst uh those are that that the ioc the international Olympic Committee has has

divided those into two different types so they repit repetitive um uh overload injuries that gradually develops over time and then the the the sudden uh overuse injuries that that occurs maybe in in one training session and and that that's interesting because in in the clinical textbooks at least uh when you read about overuse injuries and Runners a majority of them sustain the overuse injuries uh um it will say that that overuse injuries develop gradually over time not and then we can discuss what is gradually but but it also reflects to the 10% rule because usually

Runners uh calculate that based on what You' done done the previous week so the acute based on what you did the week before so that's a twoe period but is that fair actually to to say okay it it was what I did for one week that actually was the the main driver for the injury or is it more one training session that is the the um main contributor to injury developments uh for some Runners it it may be that they over time of a week or two weeks gradually put onto too much training load but

but but based on the stories that I he and also we haven't published that yet but but based on the data that that we have it actually suggests that that we may need to look more into one specific training session where the runner do something vastly different than than the runner is used to that that's maybe the way that that most injuries develop and that can be done then in in in many different ways if we look at uh putting on too much distance uh either in mileage or kilometers that's not the most appropriate measure

but but that's what we usually use because Runners understand that um uh then I would say if if you put on too much uh distance and you are rear foot Striker then you are more likely to sustain injuries in the anterior part of of the knee so that's jumper knee that's Runner need that's Pell femoral pain meniscal injury uh or in the lateral aspect of of the hip um uh or in the medial or lateral side of of the lower leg so the medial tal stress syndrome or and the pous muscles because that these are

the structures that would absorb the load when you land uh and when you go for a long distance run and you long run longer than than you normally do say Glen that you want to put 50% on top of your your longest distance so if you run let's say 10 uh kilometers and then you suddenly run um 15 kilm that that's a 50% increase how would you do that would you start out by sprinting the first 5 kilometers that would not be the most appropriate way so the way that that most Runners you know put

on the the the additional distance would be to go slow then we need to consider what happens when you go slow you take much more steps so the number of steps you take per kilometer is huge uh when you go slow and then when you put you calculate the cumul loads that that you expose your body to we can calculate that that that your anterior part of the knee the lateral part of the hip and the IMM medial side of the lower leg um are the these sides where where you you need to shock absorb

all these loads and does that then reflect on on are are these sides then these the SES that are uh vulnerable to injury if you increase your your running distance too much yes they are uh we we did a prospective cord study on that and and that was an excessive um increase by more than 30% in in your running load that that if you do that then you seem to be more prone to sustain injury in in the anterior aspect of the knee medial side of the lower leg and and lateral aspect of the the

hip and that's important because when when Runners then start to sustain an injury in the anterior part of of the knee for instance then then I would say okay then then what I know that I need to ask for distance related issues in the training schedule uh because I I I had the feeling that okay if you get an injury in the anterior aspect of the knee it it's it's usually a distance related problem uh that they put on too much distance too soon I just interject there so are you saying um that it's not

just putting on the extra distance but the fact that when you add more distance you have to generally slow down is that what you're saying and that's changing yeah that's usually the the you know uh the way Runners attack a long distance that would be to go slow uh and when you go slow then then you take more steps per kilometer and you need to shock absorb much more than you do when you run faster okay now that's okay that must be something I've I've had wrong along the way I keep thinking of things but

one stage I thought that that slow runners and fast Runners do about the same number of steps per minute the same Cadence but they just the faster Runners have a longer stri length have I got that wrong so I actually thought if I was running kiler per per kilometer run you will take fewer steps if you run fast than if you run slow because because your St longer yeah because your stride lengths longer but what about steps I thought the steps per minute was pretty much the same if you go fast or slow have I

got that wrong I don't got that data to be honest uh exactly how how the relationship is there so so we we we look at the distance because that that's what the runners usually do so they they go for a certain distance with with I get you you know the same stri length and and then more or less if they are fatigued then of course the strength will will go down but but the idea would be that that the the cumulative load would be larger in certain areas of the body um when you when you

do excessive mileage and that seems to be the case also in prospective C studies when you when we look at where are the injuries then located if you progress too much uh in in mileage and that is in in the anter aspect of the knee medial side of the low leg and and lateral part of the hip uh whereas we believe that that if you do then suddenly too much speed training then other structures will be affected uh and that would be then the um the aulus tendon the Solus and gastrus in the lower leg

uh that would be the the um elop Source in in the um flexor muscles in the hip and also the the extension muscles in in the knee um unfortunate we don't have any strong data on that from prospective C studies so Runners that suddenly runs much faster than they used to are they then more prone to such injuries we do not have have good dates on that um unfortunately but but uh and and that has technical issue about uh how how good the variable devices are to catch you know sudden increases in in running speed

over time that they're not you know 200 100 200 meters they're not too good at at capturing that um so so it's it's difficult to examine in in coure studies I could imagine also that part of the problem you're going to have is is so much variability from Runner to Runner so it goes because I I can't help thinking about because I used to be a serious Runner and I can't help thinking well that didn't happen with me well that did happen with me and I'm sure you know you can look at a whole group

you know 400 runners or something and you get this pattern but it doesn't mean each Runner so for example I used to do 2hour runs every Sunday same same and I was doing 100ks a week same same same and then for some reason one Sunday you know an hour and a half into my into my two-hour run no faster than usual no nothing I get this knee problem right and then it was basically just never went away in it for years and then and then other way you know you can say about CS going so

but then the last 10 years anytime I just try and just start getting into running so I just do like five minutes and then a couple days later 10 minutes minutes and 15 minutes and then by that time I've got three or four runs in in a week which you'll probably say is too quick now I start thinking oh I can get back into this and you know when when's the next 10k race you know in six months time or something and then I'll go out and I and my C will go you know like

within 200 meters yeah which I guess now talking to you because I think that's fair enough doing like five minutes two days later 10 minutes two days later 15 minutes two days later 20 minutes I think that's fair enough but you would say that's too much I guess from going from nothing no running that that exp because you've been you know a habitual Runner uh for many years and and you have some some experience uh then you are not comparable to a novice Runner that has done nothing for for for a lifetime so so I

think the the body has some some adaptations from the past that that that you can rely on but you cannot continue say 5 minutes 10 minutes 15 minutes 20 minutes and then go up to yeah yeah yeah I wasn't going to do that I was going to sit out so you have a Breaking Point at somewhere uh you know the problem I have the main take home message that everyone has the break points uh it's it's really individual where that is uh but if you continue doing that I I think it you would sustain an

injury at some point um and that's the same with the speed you can run a certain speed uh but when you reach a certain speed you need to be very careful gradually over time adapt the speed and and and put maybe just five um seconds per kilometer uh to to the PACE uh when um when you increase the pace rather than you know suddenly make the jump exactly by 30 seconds per kilometer because that's huge jump uh if you for instance run four minutes per kilometer and suddenly runs 330 that's a huge increase and and

and and you should really not do that unless unless you adapt to it gradually over time but that what I see in in B and the stories from the runners because as you said okay now I started running again it's fun and then you suddenly sign up for some kind of road race and and and maybe you are running with your colleagues or something and you don't want to be the ones that are that the slowest runner in the group so you you go to that road race and you haven't trained in in speed training

and you just blow it right and and and and in that particular session you may suain inuring and it comes back to the you know this sudden repetitive onset that I think many Runners will point out okay in that particular session I really was stupid I really did something that was was H much more than than I'm used to uh and and if you are able to as a clinician um identify that that that cause then you are really on the right track uh in in in terms of of treating the runner uh and and

uh avoid you know the the the issue that has caused the problem during the rehabilitation and slowly introducing that into the runnner rehabilitation regime uh I like that approach uh when when I I work with um injured Runners it's funny how you said also um that you know the assumption is is the slow buildup a chronic sort of overuse injury versus an a sudden onset and that can happen and I realized in myself sorry to talk about myself again but in the same calf I've had over the years a very very slow one because I

used to go to a physiotherapist every like month or something and she'd do the really hard massage with the Chinese spoon you know spoon really hard like just killing and that would then keep me going so then I could keep running for like another three or four weeks and then it would get really bad again and she'd do that again so that was like a chronic thing but then the same Cal 20 years later you just you know do the thing five minutes 10 minutes boom you know so it's complicated right in the iology and

and it's also 20 years later so youve got aging issues and things which I might ask you about later as well so so yeah just to bring home the in on what we can sort to interrupt but my Reflections on how we can use the the information where and and I just discussed distance and speed because if you have a person that that then starts to get aulus tendon issues or or car problems um I would say okay it it's amongst re Strikers again it it's a matter of then you are able to run for

that person a longer distance if you go slow but I would say run fast with aillis tendon problems that's where the the problem starts at least that's my hypothesis I do not have any strong evidence-based data to to support it but from a clinical practice it works pretty nicely and also for the runners with this distance related inju is okay seems to be okay to run rather fast but not for for that long uh so so so for the distance related uh courses I I use that actively for for treatment purposes where I recommend Runners

not to go that long but but but you can go at an okay Pace if you have a distance related injy for instance in the ENT part of the need whereas if you have a a course related to speeds I would not be as as as I would introduce distance training rather fast in the rehabilitation but they are not allowed to go fast they should really be careful about uh introducing speed into their their Rehabilitation regime looking at the ca the alignment between the causes and and also the that's interesting the um prevention and treatment

it makes sense but I I don't know if people necessarily I wouldn't have thought of that so you're saying if you've injured yourself doing fast running then you have to be careful going back to fast running if if you've injured yourself doing slow running uh what do you do you careful careful going back to slow running you injure yourself because you run too long a distance and then then you are careful you know running the distance but then you you can run a faster speed at a a short distance that makes so much sense but

I've never thought of it is that do people think of that is that something that people tend to cons consider or they just think I'm injured I'm just going to come back slowly no no no the usual recommendation I hear from clinicians uh is that okay you're inured Runner you should not go that long a distance so so it's the the length of the distance uh rather than the speed that is is is the recommendation but but I I would like to point it back to the the the course and say okay if the course

is speed related then I'm not too precautious about the distance then they allowed to run rather much that makes so much sense not at a fast pace yeah it's basically like specificity right the specific of the injury like what was the now I saw you had a paper um it's 2012 but I was interested you use the term training errors training errors I think you might have said that earlier as well training errors and running related injuries systematic review Etc so what do you what do you mean training errors like doing just doing silly things

like going too fast too long is that what you mean or yeah you know Glen the terminology in in sport Science is all over the place and I'm a main contributor to introducing a lot of different terms that May cover the same uh so so have me excused here uh yeah the training error uh or the too much too soon is is pretty that that's the same uh so it's it's about uh expose the body to too much uh too soon and and that's the error part um usually Runners are not aware of the error

they make so so I won't won't um complain about what they do because uh when you you you start to get experienced Runner then at least you know you get the injuries at the start and then then you realize okay my body is able to tolerate this amount of of additional training before I'm at a high risk so so the experience Runners are actually quite good at adapting both speed and distance um but then you can also introduce other types of changes that that may influence injury risk and that's where the more experienced Runners are

not that that aware actually of what they do for instance they they can switch to a new running shoe uh and and if they have been been adapted to a certain type of running shoe and they are really good at running in that and then suddenly they they switch to to a slightly different shoe um it's not the shoe that causes the injury it's running too much in the new shoe and if you're used to run for instance 10 kilm in a training session then in the new shoe you may think okay now I run

5 kilom in in the new shoe but if if the load is distributed totally differently in in the new shoe 5 kilometers is is huge amount of training load to a structure that is not adapted to to um to tolerate that load um so so so Runners should really be precautious when they do something differently in the train that's for instance running in a new shoe so so gradually built that up so and and what is that I actually don't know uh we are trying to look into it but but it's it's yeah really complex

um from a scientific point of view but but my feeling is that it's it's the amount of training you do when you do something new that is related to to a high injury risk so if you do a lot of training in a new circumstance then then you should uh be aware that that there's an increased inury risk and that's exactly the same if you are used to run in flat Terrain because that that's what you are able to do if you live in in a flat terrain area and then you suddenly go to to

a mous area and and then you you think okay it could be cool to run up and down uh in these mountains um it's it's not because it's dangerous to run in mountains it's it's good but if you're not adapted to it you cannot tolerate that much training load in in mountainous area before you sustain an inury because the load will be distributed in a different way um example they they they they they they love running and then they they they get get the the circumstance that they they increase the family size they have a

child then they bought a stroll up you know carry baby and then they suddenly run with this wagon it's not dangerous to run with wagon if you do it too much initially then injury will come uh H it's the same with terrain if if you used to run you can have a sudden baby you could have a slow baby yeah exactly exactly so and and if you run on asphalt and then you suddenly sign off for road race in sand a sand Marathon they those exist and that's fine they should exist but if you're not

used to running sand then then uh the injury risk uh by running a marathon in sand is extremely high if you're not training sand beforehand even even something changes that I think that's at least what I hear in in clinical practice that that the changes they make uh from my perspective at least uh are the main driver of of the the injury so change in combination with a high training load yeah High training Lo is not necessar running more distance that you're used to high training load could also be running 25% of of what you're

used to but it's in a completely new circumstance uh and and and for myself I've bought a new running shoe I thought okay this is fine and after 1K I sustained an injury um because the the load was distributed in a completely different way H so so maybe just 500 meters at times is enough to to to you know break a an a an experienced athlet that that is used to run 100 case per week uh just 500 meters in in a completely different circumstance can actually cause the injury if they run to too much

so that's an important takeaway isn't it because I know all of us have S have thought sometimes oh I'm probably running too much on on hard services on the road I should probably run on Grass more often so then suddenly you start running on grass but you're not used to it it may be better in some ways or not so good but you're not used to it but and you go oh I got engined I'm running on grass how unfair is that you know but you've changed you're not used to it exactly so so it's

not so the main take-home his is there's no wrong shoes there's no wrong surface there's no wrong terrain um it's it's a matter of adaptation that that the body is able to adapt if if you do it gradually over time uh for most Runners and then Irene can can can can discuss the runners that that have some severe injuries where they they they really have have some some some challenges that needs to be be dealed with dealt with and and that's a different circumstance but in the majority of Runners I I think it's an adaptation

issue they they need to to slowly adapt to the the new circumstance and and my recommendation to those Runners would be look into the future and look what what should what would you like to do would you like to to do something new for instance run marathon in sand or do you want to to run in hilly terrain you run in flat terrain normally do you want so if if you you can see your goal is is based on something vastly different than than what you're used to then then start to adapt to it otherwise

the injury risk will be high also with shoes if you buy a completely different type of shoe be careful at uh at the beginning because because the injury risk will be high I know it it's it's for some Runners it's it's really difficult because they run then they buy this really really fast shoe uh where they can set the the personal record and and they really enthusiastic and it's really difficult not to run you know 5K at at at just fast speed first time you you get the shoe on but it's really not recommendable from

a a injury persp effective because the injury risk will be high uh because you you expose different types of different structures in the body for for for a new load so so gradually adapt to the shoes and and should be able to run in in in many different types of shoes U and and that that's also good um I think to to you know distribute the load if you run at least more than two to three times per week then then have different shoes oh really data from Luxenberg shows that it it seems to to

be uh beneficial for runners to to you know distribute their load to to different structures by for instance having different types of shoes really I was not aware of that because you know it's always the thing like as you said you don't suddenly change shoes because it's going to be different and things but you're saying if you what you might have different shoes for like doing your faster running and and your grass running or or you mean just generally just just keep switching it up switching around it's it's an hypothesis I don't have any data

to to strongly supported but but it's an an assumption um and it's it's also and and this recommendation may go to the more performance oriented Runners where they want to go for the personal record and they experience over time that the the heavier the shoe is the slower they run so so then they they start to look at the weight of the shoe and and then the the the more reduction in weight you you put into the shoe then maybe the features that you they they have in there the normal shoe will not be there

anymore because because they they need to to save the weight um and then they they run in this completely different scenario and and if you at times expose your body to that uh you should be more um or you should be less injury prone if you expose your body to these situations and circumstances in in the lightweight shoe instead of just running in lightweight shoes one time per second month or something then maybe one time per week or one time per second week would be beneficial so the body can adapt over time and and remember

so to say the the load uh in in the lightweight shoes okay yeah because I know it's it's quite common I don't know because I haven't been a runner for years you know serious Runner but you know you'd have your normal sort of training shoes and then you have your racing flats for your races here and you're saying it's okay if you know you're week or something but if you're doing it only every third or fourth week then then that might be too much of a change so you might want to incorporate once a week

with the the the lightweight Sho yeah and and for the very experience or or enthusiastic Elite Runners uh take spikes as an example uh usually you don't run in Spikes all winter and then suddenly you you get this around the time around Easter you you start at least in Denmark run on the track uh and you haven't run on in Spike shoes for for six months and and and then would you then go for you know 15 times 200 meters in your spikes for the first time maybe not when you haven't done that for for

six months I would say gradually expose yourself to spikes shes over some months and and then then your injury risk will be lower uh but the problem is that you then suddenly now I'm back in the spikes and then you just yeah go full Sprint for too much uh and then the injury will occur so it all makes sense doesn't it it's just it's just giving you time to adapt now I guess it's it's not exact enough to know how much time you know like like you know I said oh five minutes then 10 minutes

and so it's not an exact enough science I guess to know and each person's again probably a bit different you know what does gradual actually mean you know that that's a really good question Glenn and thank you um and and um in in science at least uh the the gradual has been defined as as usually what you have done in in the past week so you you take all the training loads that you had done for one week and then you divide that by what you didn't done week before or the past three weeks before

that uh and and um and we discussed that heavily in in in in the scientific Community how exactly to calculate these these load um and there's no consensus right now unfortunately on on how to make the calculation I know that Tim gabbit from from Australia has has introduced this acute chronic workload ratio which is based on the acute load for for the past week and and then the what you have done the three weeks before that and that's also introduced in some of the commercial watches where where the the um recommendations that that the manufacturer

gives is is based on on the acute chronic work ratio um but but but and that that works for some of the injuries that that you know where you you are just uh close to to to your um injury uh prone line over time then then that works but but I see that many Runners uh in the clinical practice at least when I discuss with them say I it was in that training session I I did something extraordinary and then these you know calculation doesn't make sense to to to take what you done the past

week if it's actually what you did in in a certain training session that is that is uh injurious so what we are currently doing right now um and we haven't published on it yet but but we are we are digging into it uh with with the the data from the the 7,000 Runners worldwide is to look at uh what they did in a single training session uh and if you do like two times or three times more than you have done in the past uh four weeks is is that then associated with an increased risk

of injury um and and and that's fairly new we haven't done that in in in that much in in science before you know looking into just one training session and compare that to what you did uh so so then then I question a little bit about the gradual because is is that is it really true that that we should you know look at what Runners did it gradually over time for one week or two weeks or three weeks or is it more you know what they did in single training session that is is is important

it's slly both both yeah so in some cases it's what they did gradually over time where they they just pushed themselves beyond the limits multiple times and then other in other instances it's it's just one training syst where they run twice as much as they can or three times as as much as they can or they increase their their their their Pace by um you know five uh from from four minutes per kilometer to to 330 minutes per kilometer or something along those lines um um and and and then you can ask okay what what's

your assumption about the proportion is is is the predominant way the gradual thing is that what the runners report or is it you know the is it more sudden where they have one training session where it's it's uh um the the bad thing and and most Runners will report that it's it's it's just in run training session based on on the unpublished data that we have yeah that's really interesting because then then it's h it's at least this this and and and I'm really not sure about this right now and and this this is the

scientific curiosity I think that that that plays in uh but but my way to think about training load uh is starting to to get a little different uh than than the usual way of thinking with the 10% rule where usually takes what you done the past week and divide by what you then did the week before maybe we should consider single training sessions instead and and look at how much load you put into those in addition to the other way of of calculating training load yeah but the thing is this is completely new and and

and and it's just you know the scientific curiosity now that that drives me and but I think that's where we'll we'll go at least in our group in the upcoming years we we look at both the the gradual issue but also you know more sudden uh onset of of overuse injuries this the thing is though when you when you find someone getting injured in that single session because that's I can relate to that which usually like just suddenly injured and you think why was that you know you're saying it might be they've done double normal

distance or faster than they normally have or something do you find quite often you know they say oh I was totally fine then I got injured but it wasn't like they were doing anything particularly unusual so maybe it was just some sort of buildup they weren't do anything different to what they normally do in their mind who knows they might have changed grass or changed surface or something but in their mind they're like I don't know why I got injured I suddenly got injured is that yeah uh yeah sure I have I have a lot

of them where they come and say didn't change anything in my running I I run in the same shoes on the same surface the same distance the same speed I'm still injured and then I ask what what do you do in your liser time have you done anything unusual in your ler time oh yeah I was painting the whole house just just in one weekend or something like that true so so it's you know it's a training load not just based on running you your running is is you know the the same but what you

have you know made excessive painting in this case or excessive gardening or exessive whatever uh so so so the the course is it's outside running but it affects your running that's true that's true that's true okay wow so that's going to make it hard because you know if you say you're normally looking at the sort of chronic and then you're going to say oh let's look at the single session but it may not be the single session itself it's what they did the day before the singal session so that's extremely difficult to quantify uh in

in science so when did you did the excessive gardening and how to redefine that uh it's it's so difficult but but but but but you can just see see you know the the usual average person okay we should paint the house should we do that over the next four weekends uh to build up our load gradu and and to distribute it or should just do it in one weekend to to get it done still keep running the same and all that yeah exactly you paint the house in one weekend and then you're done and then

you're sore all over your body and then you run you know so if you're a I don't know 50k a week Runner or 80k a week whatever it is you don't sort of think ah I'm an 80k a week Runner but this week I'm painting the house so I better uh do less you or spread it out you T you still keep doing your 80k week you know and it's the same like you know when you said um if you decide to do more Hill running because you've got your diary and you fill it out

you've got your consistency and all that you don't want to suddenly have like a week where you're doing hardly anything you know what I mean yeah yeah yeah it messes up your it's a mindset of Runner you have your schedule and you stick to your schedule regardless what you yeah uh activities in your later time are and and at times you need to look at yourself in the mirror say okay I painted the house for the full weekend the paint over your face you're looking in the mirror the best idea to to go for for

a 20K run now if you've got spots of paint on your face when you're look at the mirror maybe don't go for 20K run yeah yeah yeah all right so what about things you mentioned a bit um I spoke a lot with um Irene Davis about um you mentioned about landing on your heel and that you'll get different types of injuries and things so what do you think about that uh concept of because I know Irene said you could get Runners that are normally heel Runners and then switch them to running on their forefoot now

again I know you're you're going to say because you've changed things too quickly or something but um you would think you would get injuries just because you changed something right but I think she said that on average um there was there's actually less injuries in the people that went from her Runners to to 4 foot Runners um maybe that's a bit I heard it correctly aren said that there would be less injuries in the knee if you switch from a rear foot strike to a four foot strike I can that's correct because you reduce the

load uh around the knee joint uh if you switch from a rear foot strike to a four foot strike but then you increase the load in in the foot and angle region um and I would assume that if you train too much with a 4-foot strike initially you would be at a excessively higher injury risk in that region so so I if you run too much yes you will not sustain the injury in your knee but then I would expect the knee to to occur in the foot or in the ankle in the aculus tendon

uh uh suus ganous muscles okay I think I got that wrong then cuz I had this idea not I can't remember exact her exact words but it was I yeah okay said that that the knee knee the risk of knee injuries will be lower if you you switch to a four foot strike and I'm fully agree with that because because the loading in the knee will be reduced but but then the loading in the foot will be increased uh and I would expect that that more Runners would sustain injuries there if they not make the

transition very gradually so you know she was talking about this thing thing um that when you land on the heel you get an initial you know Peak uh peak of the force and then then it's more a second Peak and she was saying if you land on the four foot you'll tend to get rid of that first one because you're not landing on the hill and it'll be sort of flatter and that should result in less sort of stress overall on your legs I guess we didn't in my mind I didn't separate the different you

know the car ver of the knee so I guess what I'm getting at is are you a fan of 4-foot running or do you think it's a bit more nuanced than that or I'm a fan of of every where you can run so I'm a fan of the reot strikers the midfoot strikers the four foot Strikers it will distribute your load uh differently dependent on how you strike um and and amongst those that Irene work with those with severe knee injuries uh I think they will benefit from transitioning to a forfoot strike because then they

will reduce uh the load around the the injured joint uh so that makes perfectly good sense uh I think um uh at times from a performance pers perspective it can be discussed uh if if a midfoot strike for foot strike uh is gets you to be a faster runner it is a conversation itself um but but you know the impact Peak itself from biomechanical perspective we could yeah discuss which metrics we should use in order to to estimate what what what are the most dangerous aspect is that you know the in Peak where you make

one or two really hard or or tough um Landings or is it multiple Landings not not not as severe not a severe impact Peak um but but you may you know take more steps um and and for that reason the cumulative load may may be slightly higher uh depending on on how we calculate it so it's a nerdy biomechanical discussion I think um uh and and it's something that that certainly is is Up For Debate also in the scientific Community uh if the impact Peak is is is important or not um I think Irene may

consider it more important than I but that's also because he works with other types of Runners that I do usually and and I think that's that's fully Fair okay and and with Irene we talked a lot about the you know how we were have evolved over millions of years to have kind of obviously bare feet or Minimalist Shoes uh and she was saying how the the cushion shoes make you more likely to land on the heel Etc um so I don't know I guess I'm interested in in your thoughts on on that that um not

to do with what our in said specifically but what what do you feel do you think it makes sense to to have a more minimalist shoe because that's what we've sort of adapted to and it's only been 50 years or so that we've had these fat sols or do you think the fat SS are good or what do you think well basically I think if it ain't broke don't fix it so if if you are used to run uh running in a certain shoe uh you shouldn't necessarily uh switch to minimalistic shoe or Neutron shoe

or something where where you are you know more likely to run to to strike on your for foot uh so I think um that Runners should should pick the shoes that they find comfortable and and that that works for them uh and not necessarily transition to to a minimalist shoe just because uh it suggested from a Evolution perspective that that that that what we did million of years ago so I think we as humans are able to adapt to to many different circumstances uh and and we are able to run in in many different types

of shoes and we able to learn uh the body to to tolerate the loads over time if we introduce new types of shoes in a very gradual and and um you know balanced manner uh so I would not say that everyone should should buy minimalistic shoes for instance I would say there are many many different types of shoes on the market and that's really really good because then Runners that have certain injuries uh severe injuries will be able to you know buy another shoe where the load will be distributed away from from the injured structure

and that over time I think it keeps them running U and keeps them active uh in an active lifestyle and that's good um because there's some data from the US suggesting that uh that Runners that sustain sa injuries will actually start to have an inactive lifestyle they will not switch to another type of sports uh and that's what provoking that a lot of cyclists are XR Runners now they can't run ride some some Runners would just be demotivated and and say okay now I'm I'm lying on the couch instead um so it's true that many

will transition to to cycling but those that sustain injuries and need to quit running because of injuries uh some of them will also so do do the the unfortunately lifestyle I can totally hear why they do that because I'm much better Runner than I'm a cyclist and it's very frustrating so maybe I'll go for maybe I'll just give up the cycling because like like they do because it was so crap because I'm like in the top whatever percent of Runners and then cycling it's like anyone can cycle you know if you ride enough any anyone

can almost be good on the bike but running is like you know you've got good Runners and not so good Runners and technique or something that's really frustrating okay um all right so what about other things I don't know if you want to talk is there um other things you want to talk about with load and things like that or I was going to ask you questions like you think stretching makes much difference and strengthening and you know others like for prevention do you think there's other things people can think about for prevention other than

um CH just changing the load slowly and changing the surface slowly and all things like that yeah it's maybe some Reflections on on science for for the listeners uh so so when they they read something in the news uh papers or in the magazines or on the Internet or or something they they should about causes of of injuries and and how to prevent them um they should really consider about how science is conducted uh and from my perspective as as you may have have have heard training load is is really really important and if training

Lo is not a part of of the model uh so the statistical model that that researchers use uh in in their scientific articles how are they then able to discuss courses if training load running is not a part of the model and and a lot of studies are conducted where they uh examine uh strengthening or sleep or body mass index or age in relation to injuries uh and and that's also good because then you examine what we call predictors who are more likely to sustain injuries than others so we can identify that that those Runners

with previous injuries are more likely to sustain injuries than those without previous injuries those with the high BMI are more likely to sustain injuries than um those with low BMI but it's not necessarily because of the BMI or because of the uh previous injuries that they are more injury prone is because they run too much with a high BMI or too much with previous injury that they sustain injury uh and and and and that that's really important for the listeners to to consider because um it's really difficult to identify causes underpinning running injuries uh when

you need to include uh training load uh in your models uh it's it's rather complicated um so so so if you you read a study and and you you should maybe just consider have they about courses consider have they included training load at all and if they haven't I would be suspicious if they actually are studying courses in that particular study so do they not usually if they're looking at Runners and saying okay let's add stretch stretching or add strengthening do they not usually keep an eye on um uh their training distance for example uh

do they not try and say don't change it or something like that yeah so so usually they take all the the uh risk factors or predictors and put them into to models uh without you know um including training load and and that's usually because they they haven't measured training load in their studies over time so so they make make some baseline measures of of body mass index height weight age uh some some questionnaires about previous running experience and and running history and so it's more like epidemological sort of study have people not done studies though

where they've said let's get a bunch of Runners let's let's you know uh randomly allocate them into two groups one that does strengthening you know calf raises or something and one that does no calf raises then they keep the rest of they running the same have that people not done that things like that or no no yeah because that's exactly the the problem with with many studies that that uh then you assume that the runners in the two groups are running the same but if you then randomize a certain group of Runners to do some

strengthening or do some uh other type of of activity are you then sure uh they have time enough to run what they used to I would anticipate at least from many of the runners that we recruit for for for scientific studies they are really busy people and they are family uh they have families so so they have limited time and if they're in a study and they told okay now we need need to do some some strengthening uh two times per week okay but but then that will affect my ability to run because I only

have four hours per week uh available you can't R them you could so those that are randomized to the intervention um may also reduce their running uh as a consequence of of the limited time they have to on a weekly basis compared run more question is it then the Str training that actually or is there a reduction in running that actually is is the main driver for for the potentially um limited inis amongst those that randomized to a a strengthening program compared to those that are not but in general we we we lack studies on

on prevention that includes training loads as a as a central component I think resarch just assume that Runners are running the same in the groups but but I I would say that assumption is is um open for discussion at least yeah because if if if the group that didn't do the strength training ran more than the group that didn't do the strength training you can't even include them or you can't even make any assumptions and you're saying that not enough Studies have been done where they've actually matched the training yeah yeah yeah that's too early

to say and that that's really what I think we need to consider uh and building our studies based on what we call csal models so and and and identifying training load as a necessary component uh is crucial I think if we should both discuss prevention and and treatment of of running in okay and and one thing I've I've U read about and heard about when you're looking at training loads is rather than just you know saying how many kilometers a week or are you doing how many miles a week whatever you multiply it by your

rating of perceived exerion or something like that you know for running because you know cycling obviously you've got meters and things like that so you can work it out for the week to people do that to try and quantify you know like the speed and the intensity the distance and the intensity per week rather than just people do that yeah that different ways to do it uh let's take the the mileage first as an example uh re that's a funny article I think it's Max pette and colleagues about the runners Obsession about weekly mileage uh

so so Runners are really focused on mileage as as as as the metric they use and I also use that myself so I don't blame it but but but scientifically um it's not necessarily the best metric to use uh we use it still in in in science because we are not clever enough to to to you know introduce other measures but but let's just say that that we were able to calculate a structure specific uh load per step and then make a then then per running session then make a cumulative load for each structure based

on the the load per step in each structure that that has been been provided we look very much into this and think this is the way forward uh it's highly Advanced but but you know in in order to use the the commercial watches to to to estimate a load per stride you could for instance use vertical illation how how how much you jump uh running speed so the fast how fast do we hit the ground um stride length uh and other and and your body mass index in order to to get an impression about the

load that that you actually uh introduce per stride and and if you're able to do that uh then then do that per stride that is taken in a running session uh and do some mathematics it it could be interesting over time to see if if we could calculate you know a a load in each structure in the body for each running session that would be the dream scenario for me rather than just relying on on weekly mileage as the main driver for injury because it's it's too simple so using your word earlier nerdy that's that's

the really nerdy approach but what about can you doist so I I'm really not good at biomechanics so I would rely on on some engineers and others to to be good at this but uh yeah it's the dream scenario for an epidemiologist to have more Advanced Data uh from a from the biomechanical field uh than than we have today uh I mean I was just joking that would be fantastic if they could do that to quantify the the load but but do people use the the rating like something like like how do you do the

intensity and the duration so do you do something like if you do a 10k run but you do it slow versus fast but you're saying that's not necessarily that simple either because you're doing more steps so you can't just go okay 10K times your rating of perceived exerion which is assuming if you're going faster it's harder uh would give you a higher stress but you're saying it you might you would actually have less steps so in some ways that may not be a higher stress so it's too you can't do it that way ex yeah

and we tried a little bit to look at the interactions between uh speed and distance and others have look at the rating of perceived exertion and distance and you know trying to combine these measures uh it could be a way to go forward but but then it it it gets really complex also from a statistical point of you uh so so my feeling right now would would more be to try to to calculate these cumulative loads uh uh per step uh and and if we based on some biomechanical modeling could could then uh estimate or

approximate how much load that is distributed to certain structures then I think we could get some interesting data that that that could be a better measure of load than than we currently have in in the weekly mileage or or milus per run session or something like that right now what about recovery I know you had again this is back in the this is 10 years ago what about recovery so a p perspective study on time to recovery and 254 injured novice Runners so what have you got there on recovery sort of uh yeah we we

had a prospective Court study and and some of Runners sustained injuries and then we followed the Inu Runners over time to see uh when were they able to to take up running again without having any uh complaints um and and it was uh interesting to see that that uh as expected some injuries recovered rather fast that was predominantly the injuries in the muscles uh whereas the injuries in in the um the tendons uh they were longer lasting uh in particular in in the uh arch of the foot the planta fitis uh that that was not

a good injury it took a long time for the runners to um to to you know successfully returned to running I I believe the median uh time to recovery was yeah up to three four months if I remember correctly uh maybe even more amongst the runners that recovered but but we should also consider in that study after one and a half years we need to to stop the data collection and and and and around 10% of Runners uh did not recover after one and a half years uh and and that's the exact Runners I talk

about for aren there that that's where she picked them up and and tried to do some some G retraining or other issues U interventions with them which is good uh because recovery yeah is is significant and and then the time for for for return to running can be uh really long especially for detent related injuries and we know that from from other literature as well and it's confirmed in running um but it's it's surprising to see how many of the the runners that did not return to running because of their running injury uh it was

higher than expected unfortunately 10% and and were they was there particular injuries like you mentioned PL of fasciitis so yeah it was also PL of fasciitis that that was not a good one to to have then the Minal injury was was also one of them and it was but it's always open for discussion if if the uh injury in the minuscal uh part of the knee um was it there before uh so it was just you know it was not caused by running it was there before and and then when they started running it it

blew up again or or was it actually running that that caused the injury it it can be discussed um from a e theology perspective but um but but certainly some injuries are are better to get than than other so to say um okay now I know um before we came on you talked about you know in the in the weeks before you talked about wanting to talk about shoes and injuries so I know we've talked about shoes a little bit but did um is there anything else you want to talk about with shoes injuries um

we are not there yet with our science and shoes we would like to know when a a runner goes to a shop buying a new shoe uh how long is that Runner able to run in the new shoe before being at high risk of sustaining an injury we don't know that yet uh um and that's really unfortunate because it it would be very beneficial also for for those working in in the shoe shops to to be able to to advise runners okay instead of just saying you should be precautious but what exactly is that uh

we don't know that and and that could be interesting to to study uh when you do a a minor change for instance if you go from one model of a shoot and buy the new model usually they they change the model once per year so when you go from one model to to the next uh most likely you are not in safe Zone but but you are able to run longer in in in in the the same or not the same model but but the new model of the same shoe that you run in before

then if you run in a completely different shoe that that has has other character istics but but how much is that is it should you if you go from a certain shoe to the new version of that shoe is that reduction of 50% or 60% uh in training load whereas you should Reduce by 90% if you buy a c completely different shoe or is it 90% in one shoe and and 70% in the other shoe we don't know and I think that could be really interesting to examine um but it's a different study to to

make because there are so many different types of shoes so you should really have a lot of Runners to to be able to do that yes now everyone's always interested if you're talking about shoes are these new you know the the new shoes the ones that save on average I think do you agree about 4% of energy I guess it depends how fast you're going but must be totally honest with you I heard you discussed this with Irene also um that that I'm not very much into these uh metrics about how much energy is saved

in in different types of shoes uh at the moment um that's fine but I think I think there is evidence that they can reduce your oxygen consumption by a little bit at the same speed and that may help going faster the thing I was more interested in I guess is I think they're right and also the world records are broken and stuff so yeah it's it's uh seems Seems likely that that's the case I think it's something like that 4% or so but it does indeed seem to be um causing some reduction in in your

oxygen consumption so you can do do a little bit faster but what I was interested in asking you about is um I had Andy Jones on here and he was talking about how did keep chogi break two hours for the you know that paste marathon and he was actually saying um that he reckons that that the softer shoes actually make you feel less fatigued in the second half of the marathon I don't know if you've heard anything about that and whether you know if there's any sort of differences in injury rates in those shoes because

I've also seen some people say when you put the shoes on you feel like you're just all over the place almost going to fall over so again I I assume you'll say you got to be very gradual but these shoes although they don't have a long a long mileage rate they kind of wear out quickly yeah I'm I'm certainly not an expert on performance enhancement uh in running and and so so I would yeah I all all of course have my personal opinions and I think it's it's fun to to run into this new shoes

and and try them out and and try to break break some records but but uh from from a injury perspective I think it's just similar to all other types of shoes that that yeah these shoes with carbon plates or other type of of new uh introductions from from from a technology perspective yeah you just distribute the load differently and and expose different structures to to to different um ways of of working uh and and of course it will affect your your injury risk if you're not adapting your body to to to tolerate the new load

that is is exposed to you in in in one of the new shoes so yeah the the take home message from an injury perspective is the same yeah exactly which makes sense now a couple questions from Twitter I know you don't have you don't really look at Twitter but Martin uh again it might be a bit of a technical one but talking about the tendonopathy so the tendon injuries you mentioned earlier so recovery with achilles tendonopathy tendonitis concentric versus Ecentric versus isometric work stretching back to running protocol should you vary intensity speed shoes I guess

there's a lot of different aspects in there do you have any thoughts yeah if you look specifically into the killers tendon uh and and this is my Approach which is you know pseudo scientifically based because I think we have some some some some arguments but but some of the the things that discuss now will will also be based on my clinical experiences so I have a runner with um aillis tendy initially of course do the the strengthening protocol and and all the the you know standard things uh can be discussed if it should be only

Ecentric or E contri uh but but what I think is important here is the return to running regime uh and and what I do when I recommend a runner with a Kindle to return to running is one go slow don't go fast uh because uh the function of of the the the the leg muscles the the Cal muscles is is to to generate speed and the more speed you generate the the more prone to to um to to an excessive load you are uh then I would look at the heel to tow drop in the

shoe I also think you discussed this with aren uh so if if you uh have a very flat shoe uh the tendon will be stretched more which is not a good case so so maybe start out in a shoe where you have a high heel to throw drop um so the aulus tendon is not stretched as much as it is in in the flat shoe uh go in flat terrain because if you go uphill uh you will make a dorsal flexion in the ankle and then your killus tendon will also be restretched so so go

go in flat terrain initially uh and then avoid you know to um what's it call in English avoid sand for instance because when you land in the sand then your heel will go down in the sand and then you need to pull up so you know slow speed flat terrain uh high heel to tow drop and and and no sand uh initially in the rehabilitation then there you gradually introduce some of these these issues um when you uh when when you get further into the the running regime sounds like good advice that's the way I

would for a Kill enough you introduce return to running again that sounds like good good advice another one on Twitter is is NE Osteo arthritis compatible with running if so how to run to minimize pain I we see a lot of Runners continue running um even though they have ostop fritis uh because they got get the health benefits uh from the active running lifestyle uh and I think that's good uh the consequence of of sitting in the couch doing nothing is much more severe and and the question is also is is there a negative con

consequence on the o osteitis if you are running and that's also heavily debated in the scientific Community others are much better than than than I am on on on this particular topic and I could encourage you to to invite persons uh with expertise into the podcast on on this topic um but personally I would not um say that people with mild orries should avoid running I think it's okay they run uh as long as as as they feel comfortable and and and feel that it's it's good for the overall health uh at least it's it's

better than just having an inactive lifestyle so if running is is their main driver and that's what they motivated for and they would not go out doing some other types of exercises yeah when why not running that that's perfectly fine I think so go again sort of based on symptoms yeah so if it was hurting while you're running then you would maybe try cycling or something yeah in in the data set we have uh with with the and it's also again unpublished data um but but uh those Runners with osteitis yes they report more running

BL injuries than those without uh in the ostearthritis so yeah it seems like the injury risk is is higher amongst those with ostearthritis why that is the case we don't know uh but but at least those with osteri should should be aware that that there's a significant IND risk uh and then they should be very precautious in in their approach to running and not that they should not be running because I think it's fine but they should not just be very precautious because it seems as if the injury risk is high in that particular group

yes okay now Jackson said we sort of touched on this earlier weight training so uh or we talked about strengthening Jackson saying weight training is extremely beneficial to improving running performance and enjoyment as well as preventing injury would you uh I guess weight training is very it's a very broad you could be doing bicep curs right but um I'm assuming what it is and but do you think is there data on that is it is it no strong data no as discussed before um they haven't really taken into account training loads uh when when doing

these types of studies uh and and many of the studies we have are not on Runners it's on Military populations uh so I haven't seen you know the the the the large scale randomized trials where they randomize Runners into a strengthened group and take their running uh scheduling into account uh versus a group where they are randomized to to just control uh where they also should take into account their running during the followup period I haven't seen such studies this year so so in my perspective right now it's uncertain uh how well strength training will

um assist preventing injuries I have the feeling it it can prevent something uh but but uh do not have strong evidence-based sta to support it yeah because it seems like um generally people always say calf you know if you get calf injuries you should do uh heel raises you know know Etc but you feel like even that is a bit premature just to stay and what I say now would is just personal opinion so um the the speed related injuries uh so that's the kill tendy the calve osur in the Anor aspect of the hip

joint for instance I think it's would be very beneficial for runners to strength training do some strengthening on on on these uh structures because they're really exposed to a a extremely high stretch and a extremely high load in in certain situations and and I think you can reduce the IND Risk by by exposing yourself to to some some maybe plyometric training or really heavy strength training um whereas I'm not too sure about the distance related injuries uh if if strength training really pre is beneficial in preventing injuries in the Anor aspect of the knee for

instance it's beneficial in in treatment U purposes or for preventive purposes I'm not too sure but just just personal opinion Al with the Spade because I I keep thinking of because we've been very endurance training Centric I just realized that because I tend to do that because that's my background so you know other people might be thinking running related injuries oh great I'm he's going to be talking about they're going to be talking about hamstring PS in 100 meter sprinters so we haven't really been doing that so when you talk about speed are you talking

about like intervals for endurance train athlete or you talking about the sprinters and things like that um the funny thing is that at times the recal runners also become sprinters uh because then they they participate in a road race and they Sprint the last 200 meters towards the Finish Line uh so so you know this the sprinting should not just be considered as those running 100 met for Fast Pace very good pacing that is not good pacing is it because it's always also when when Glenn you go out with a with your training body and

and then you go for easy paced run and suddenly your friend will say okay we Sprint the next 200 meter to to that shop and and and then you just go all you can and then you get your your injury right uh so so I think if you are such a type where you at times expose yourself to such type of Sprints uh and Runners do that at times especially males um then I think you you could prevent some of those injuries by doing some strength training uh um but of course you'd also consider you

know when you should Sprint start by gradually introducing uh the speed instead of just you know going full Sprint where when you haven't done that for for six months that that's yeah highly risk to do that yeah over time and maybe assist by by adding a little strength training but but that just just a feeling not not based on evidence the other thing I was thinking about because we have been a bit endurance Centric here is if people want did want to think about team Sports and More sprinting and and injuries they could listen to

the podcast by Christian thorborg that I had on to also from Copenhagen where he talked a lot about those sort of injuries and how to try and prevent them and things now I've also got um a question here from John he had a series of questions some of which we've covered plan plan fasciitis those sort of things we've talked about running when older so um can't help thinking you know as you get older you tend to feels like you hurt your car more often and maybe hamstring and things do you know do you know if

there's much evidence for that uh it's when we look into the literature it's it's not totally straightforward because it seems as if the older Runners are not necessarily having more injuries than the younger Runners but I think that's because the more the older Runners are more experienced so they don't expose themselves to the dangerous situations as the younger inexperienced Runners are um but as I'm also getting older and and and looking at at at older athletes what I see which is not evidence-based but I have the feeling that it that that might be something to

it is um you know the range of movement motion that that uh many uh older Runners do not have the the same flexibility in the body as as you have when you you're young and and and they are really able to run slow so they they run in in you know these range of motions where where they don't need to get out of in the end of range but then if you are as an old person suddenly start to Sprint or gets your body into a position that is is in the end of range and

you're not used to that then I think the injury risk is high and and there I think stretching in in the end of range maybe could benefit the older Runners uh but but that's not something I have seen any studies on it's just an an assumption and and a feeling that that many older Runners May benefit from from some do some some stretching exercises uh because then they are not as as vulnerable when they go out in in the range during a a fast-paced run for instance okay so it seems like there's there's not a

lot of evidence on some of these things yeah not enough Studies have been done to no conclusively I would say um there's a lot of work to do and and that's also what excites me the Curiosity drives me we are not even close to being there yet uh we need to do a lot more more sence in order to help the runners out there but I think we we start to to have pieces of the puzzles built uh and and some some uh directions which can be then based on uh or runs can use them

in in practice and clinicians can use them in in in the clinics uh and that's important and I hope I have served as as uh as a you know good um distributor of of of the knowledge that that I currently have uh to to the community and and that has been insightful and and helpful absolutely even though I'm not a native speaker so I I know my Danish voices and danish Tong not totally appropriate but I hope you got across very good all right so just we'll finish up in a moment by just thinking uh

with the age do you think is the injur is there evidence that the people older people when they get injured they take longer to recover because that would seem to make sort of sense yeah that that's also my feeling I haven't seen any good data from from the perspective Court studies yet but but uh but I get the feeling that that time to recovery is long if if you are older yes so so the time between hard running sessions should be longer amongst those that are older that that's the feeling I have yeah all right

the other one I like to often ask as well as age but also are there sex differences so are there differences in injury rates or recovery from injuries or things you know between the Sexes no that's a debate in the scientific Community some believe that that there are some some differences uh but it's not you know from my point of view it's uh not sex is not a a cause of injury per se I think males and females sustain different types of injuries but they will be equally prone to injuries if they train too much

so both males and females will sustain injuries if they train too much uh then you can always argue if if certain groups of males uh are more prone to injuries because they train more excessively than some types of females for instance uh and that might be the case um but but um but but still I think that there's no gender difference or sex differences uh in in in injuries if you train too much uh both males and females will go down if if if they try train excessively and and I don't think there's huge differences

in the adult population at least uh uh in how much training load that is is um that women and male women and men can tolerate before being at high risk I think that's that's more or less the same then it can be discussed in amongst the adolesence where where they are pubal development or something I think there might be some some sex differences there between boys and girls but I'm not really good in into that aspect so I I'll don't go into that well thank you very much for coming on what I do like to

do uh just to finish up is have some a few takeaway sort of messages what would you like people to take away from this chat today yeah running too much too soon is associated with high Indy risk uh you should be precautious when you introduce something new into your training new can be a lot of different things for instance you could go longer than you used to uh distance-wise and if you do that then you if you're a heal Striker at least a re Striker then you would be prone to injuries in in the entry

aspect of the knee medial side of the lower leg and lateral aspect of the hip you could also go faster than you used to then I would anticipate that you are prone to sustain injuries either in the aillis tendon the calf um the hamstrings or in the elur um then you could uh do many different uh changes you could change your running shoes so be precautious when you introduce a new shoe uh build your your load gradually over time uh in the new sh if you suddenly change surface uh introduce the new Surface also over

time so just don't run uh 10 kilometers in sand for instance if if you're not used to it then then I would suspect you to have a high injury risk um uh if you go from from Flat terrain into Heil terrain for instance uh adapt to the he terrain so you just don't don't run 15 kilm in in Hil terrain without being adapted to it yep also with strollers if you run with backpack if you run with suddenly starts with running with with accessories uh do that gradually over time also yeah and also your Laser

Time activities if you have done something uh outside running uh that that fatigues your body uh that can be painting gardening or whatever uh uh then be precautious in in your running also um because then you are you are not as as um good at tolerating the load as as you are if you don't paint the house or don't do the the garden right um so that that's really the main take home message that there's no wrong shoes wrong surface or run wrong terrain you can adapt to it and and and you can you should

be able to to um um have a successful running career in many scenarios um unless you have some severe injuries which which are really tough and that's where iren's podcast will you more than mine right perfect well that was a great little summary at the end and uh yes so everything in in moderation everything gradual gradual gradual gradual yes and and think about the training load not just in as you say distance which people tend to get obsessed on there's a lot more going on than that okay well thank you very much for coming on

for having me was a pleasure thank you okay I'll see you next time see you mate see you bye bye I hope you enjoyed this podcast please like subscribe pass it on to your friends and colleagues check out the other podcasts thanks again