 Alright, so junk miles. We hear this term thrown around a lot. This idea that you are wasting your time running easy and that you should be focusing on quality over quantity. Don't focus on running all those easy miles. It's just junk mileage. It doesn't give you any fitness. Let's dive in deep and figure out if there's any truth to this concept of junk mileage. If there is, where do you draw the line? Where does junk mileage become quality mileage and what is the difference? Does it matter? Does it differ from slower runners to faster runners, amateurs to elite? Does it differ over the course of a career or over time as your running fitness improves? Let's get into this. It's a cool topic and I want to talk about it today. So we recently did a Q&A video here on the Lone Trail. If you haven't watched it yet, you can check it out. I'll put a link to it there. And one of the questions was regarding junk mileage. And my answer really simply put is that I don't believe it's a very valid concept to focus too much on the junk mileage idea. Volume is important. Run easy. Run more. And typically for most people, if you're running more at an easy intensity, it will translate to an improvement in fitness and performance. However, and this is what I didn't really talk about in the Q&A video and that's what I want to get into today, I do on further reflection think that it is necessary to define what junk mileage really is because I do think there certainly is such a thing as junk mileage. It is possible to run too slow. But what is too slow and how do you know? Just before we get into the video here, I want to mention that I've just launched my new coaching website, mgjcoaching.com. There's a link in the description. I'm offering customized training programs, online coaching for runners of all levels. So if you're interested in sort of taking your running to the next level, or if you have any questions, or if you just want to do a consultation, just get some advice on your current training. You can do that. Again, there's a link in the description. Check it out. Let me know what you think. And let's get on to the video. So first of all, let us define the purpose of doing mileage, right? Like the purpose of doing easy running. Why are we doing it anyway? Well, in a nutshell, we're trying to develop the aerobic system. So it spans from pretty easy to up to about something we could call like moderate type of pace, not above lactate threshold, we're below lactate threshold. We're still fully aerobic. It's a sustainable pace, that sort of thing. We're developing the aerobic system. We're talking about developing capillaries to your muscle cells. So these blood vessels that can transport more blood and therefore more oxygen, remove waste product. We're talking about developing the mitochondria within the muscle cells so that they can oxidize fat and carbohydrate more efficiently, produce more ATP faster, to be able to move you forward when you're running. We're talking about developing the heart. We're talking about developing enzyme characteristics of the muscle cells. We're talking about possibly moving the fast-witch muscle cells towards being more like the slow-twitch muscle cells so that they're more conducive to long distance running at a submaximal intensity. We are essentially, this is some of the things that we're dealing with when we're developing the aerobic system. Now, is there such a thing as a threshold somewhat? Is there some kind of threshold below which we are not really getting any significant stimulus to these factors that I just mentioned? How hard do we have to run in order to produce a training effect in the factors that I just mentioned? Heart, heart size, mitochondria, capillaries, that sort of thing, enzymes. Well, yes, there is such a threshold. There is a point at which below you will not really get a training stimulus. And this point depends a lot on your current fitness level. And what I mean by that is, if you're taking a very sedentary 60-year-old woman, cardiac patient, perhaps even, really, really poor cardiovascular health, going for a walk for her might in fact get her into the, some people are even into the sort of close to VO2 max type effort just from walking. So for her, that is high quality training right there, just going for an easy walk. Whereas for someone like me who's in the middle range, certainly not elite, but not an amateur or whatever either, I'm fairly fit. When I go for a walk, my heart rate is like 60, 70, 80. It's low. I'm not working hard at all. So if I suddenly added a whole bunch of slow walking to my training regimen, that wouldn't really improve my fitness at all. Even if I added 100 miles a week of walking, sure, I would get some structural development. And my tendons, my muscles, my bones would probably, you know, find some benefit from that. But then again, I'll probably better off running, which is more specific. But from a cardiovascular perspective, from an aerobic development perspective, that would not be good. If I still was running the amount that I am now, then, you know, it could possibly even damage my gains because it would mean that I would spend all this time doing this low impact activity, not allowing proper recovery when I really should be after my workout, sit down, eat, rest, recover. But instead, I'm out walking for three hours, right? That wouldn't be conducive to recovery. Short little walk in the afternoon, perhaps that's good, just getting some blood flow, for sure, but adding a lot of walking, not so much. So here we go. Is it beneficial for me to do this? No, that would certainly be called junk mileage. Whereas, again, for another person who's not as fit as me, going for a brisk walk might actually put them right in that perfect zone for developing the aerobic system. And if we are to use heart rate as a gauge, right, and it's not a perfect gauge, but if we are to talk in terms of heart rate, probably somewhere around the, you know, 60% of max heart rate type of intensity, that's probably where we're starting to see development of the aerobic system. So meaning, if you're running at 50% of your max heart rate, suppose your max heart rate is 200. If you're running at 100 BPM, or even less like 40%, like, I don't know what that would be like, 90, 85, you're not really going to see good gains in terms of your aerobic system. So we could really, we could say that's junk mileage. So in order to get good development qualities, if you will, of your running, you probably want to stay somewhere from 60 up. We'll get to the upper end soon, off your max heart rate in order to get gains, okay? Anything below that would probably be called junk, we could call that junk mileage. However, this is a big one. In the beginning, and for a while there, even at a higher level, you've got to differentiate between what types of systems you're training, right? So sometimes you are focusing on, you know, if you're focusing on developing the aerobic system, or at higher intensities, you know, your VO2 max, your lactate threshold, that sort of thing, then being in the right intensity range, being at the right pace, that sort of thing is key. You know, that's what matters. Just like I just spoke about with the aerobic system, you do want to be probably above 60% of max heart rate in order to get a sufficient stimulus to the aerobic system. However, there's another system here as well, and that's the structural system. That's your legs, that's your bones, it's your tendons particularly. You know, those are typically, typical, you know, runners, they get a lot of tendonitis. Tendon pain, you ramp up mileage too quickly, you can get some tendon pain, perhaps even stress fracture if it goes too far in your bones. We're talking muscle strains could happen. All kinds of structural problems can develop from running. And so as you're building mileage, especially as a beginner, you want to focus on building it very slowly and doing a lot of easier running to condition your structural system. And this is irrespective of your aerobic system. At the beginning and even later, you've got to realize that the structural system benefits from a lot of easy volume, slowly but surely ramping it up, even if that means that you are below 60% of max heart rate, right? Even at lower intensities, which theoretically could be considered junk mileage from the aerobic system point of view, from the cardiovascular development point of view, it's a junk mileage kind of thing, but it's still a good stimulus for your structural system. So I don't want to focus too much on junk mileage when on dealing with beginners. Beginners, there's no such thing as junk mileage for beginners, basically. Develop your structural system, run lots of easy miles, do some walking breaks, go for walks, get a robust body, develop those bones, those tendons, get used to moving, carrying your body weight, essentially, over long distances. Same goes for marathon training, like Renato Konova, the famous marathon coach. He prescribes, even to his elite athletes, he prescribes early in the marathon cycle, what he calls general resistance runs. And that's very low intensity, but they're going for long, so they might be out there for like three hours, okay? The purpose is not to train the body metabolically. We're not working on the aerobic system, we're not working on the on the lactate threshold and that sort of thing. It's strictly about developing the structural system, as well as the mental aspect of being on your feet for a long time, just being out there concentrating for a long time. So these are relaxed efforts, long efforts, junk miles, essentially, from one perspective, but from another perspective, we got to realize it's actually high quality miles when you're thinking about how they are conditioning the structural system. Now, back to the sort of aerobic development point of view. Starting at about 60% of max heart rate, that's probably a good place to sort of start considering it to be quality enough for developing the system. And how high does it go? Well, you'll always be developing your aerobic system somewhat, but the point is at a certain point, you're working more in those intense zones and you can only do that for so long. And one of the biggest stimuluses to the development of aerobic capacity is actually time. So the more time you spend in that zone, the better, which means that if you go to high intensity, you'll not be able to sustain for long enough. And therefore it is not as effective for developing the aerobic system. So we typically say between 60 and perhaps 80% of max heart rate, that is a good range, you know, that's zone one, zone two type range, great for developing the aerobic system, spending a lot of time in that zone, one, zone two. So as long as you're within that zone, as long as you are running, spending time within that zone, you are getting benefits and it's not junk mileage, right? It doesn't matter really what your pace is. You've got to remember that as you get fitter, your pace will get quicker. So at a certain point in your fitness career, you actually have to run a fairly relatively speaking fast pace compared to what you did earlier maybe in order to just be in that range. So what typically, you know, a few years ago elicited a heart rate of like 70% of max for you. Now the same pace will probably only give you a heart rate of like 60 or even 55. And that then you're in the lower end of, you know, sort of getting into the junk mileage kind of realm possibly, unless you're working on your structural system. So you want to be aware of that obviously and increase your pace to stay within the right intensity zone. Now on top of this, on top of the aerobic part of training, there's the lactate threshold, there's the VO2 max, there's critical velocity, there's there's a pace training at race pace, there's speed training developing neuromuscular capacities, which is also kind of a structural thing. So there's all these different training elements, of course, that you'd need to add on top of this aerobic development. And a lot of people talk about only the higher, you know, from lactate threshold and up talk about that as true quality work. And that's on top of an aerobic base, right, the base of aerobic work. But I would say that even the aerobic work is quality, as long as you accumulate enough time of it. But it's never a waste of time to run easy as long as you're within the right range. But it could theoretically be a waste of time, aka junk mileage, if you're not in the right range, and you are running too easy. But as I said, for beginners, even if you are theoretically below that intensity range, you are working that structural system, you are working your ability to be on your feet for longer. And that's a beneficial adaption as well. But likely if you are a beginner, even easy walking, even brisk walking, at least, should elicit a heart rate above 60% of max, and then you are indeed training your aerobic system. So you got to sort of keep that in mind. As you get fitter, if we're moving up to like an elite level, it's kind of turned around a little bit, tables are turned a little bit, in the sense that, you know, your aerobic system, your capillaries and the legs, your mitochondria, the size and the density of your mitochondria, mitochondrial networks, the enzymes in your muscles, the myoglobin content, all these kind of things that are good for aerobic exercise, which essentially means anything above like two minutes in race duration, anything above the, you know, from 800 meter, even that's like the crossover point, but really like 1500 meter runs, races, from there on up to the marathon and beyond, they're all very similar in the sense that it's mainly aerobic. So any sort of event like that, any sort of training like that will rely on the aerobic system a lot. And so developing those capillaries and mitochondria and all the stuff I mentioned is key. And here's the thing, it actually responds to the amount of training you're doing, but you can't just suddenly start running, you know, 150 miles a week, that takes years to build up to. So over several years, and I've, you know, Konova says it takes eight to 10 years to build your aerobic house. And I've heard this being mentioned several times before, you know, it does take about a decade to develop an athlete aerobically. And it can take longer if you're not working at a, you know, peak progression rate. So it takes a while to get to a point where your aerobic system is fully developed in your body, in your heart, in your legs. You know, if that takes 10 years, then for all of those 10 years, more so in the beginning, but even still towards the later stage of those 10 years, that sort of easy mileage plays a big role, more so in the beginning. Eventually, when you're at a peak level, you can actually get away with less mileage, theoretically, because you've developed your system and maintaining any system takes always less time, energy, whatever, than actually building it in the first place. So maintaining a house takes less energy than building it. Same thing with the aerobic system. It takes you a lot of easy mileage, a lot of time, a lot of, you know, a lot of mileage to get to the point where you are at your peak fitness level. And now that you are there, theoretically speaking, let's call that an elite athlete or an athlete at the top of their potential aerobically. Now on top of that, they will start working more on the threshold, more on the VO2 max, perhaps more on the race-pace specific work. And they can get away with less of the easy mileage, even though it is still important for recovery purposes, getting blood flow in between heart sessions, maintaining somewhat of an aerobic undercurrent, we could call it, along the way, having some easy to moderate runs in between the harder efforts. So it's still always there, this aerobic base, but they can get away with less spending less time on the easy place and more time on the faster quality stuff. And they can overall probably reduce their mileage a little bit or even have the same mileage, but have a bigger proportion of it being high intensity running. So summing up, early in your career, low intensity, working more on the volume, less on the quality workouts, and just accumulating time for your structural system, but also for your aerobic system is key. The more you progress in your training career, the more you move towards reaching your potential, you can sort of shift the ratios towards more focusing on the high quality and less focusing on the low quality. But even for an elite athlete running at 70% of you to max, it still is going to be beneficial. It's going to maintain that aerobic system to some extent. Whereas when you're building it in the first place, it is important that you are pushing it and actually building it. So I think for an elite athlete, there is more of a chance of getting into some junk mileage. They should probably realize that they're probably maxed out their development of the aerobic system and they only need to maintain it now at this point and focus more on the high quality stuff. Whereas for a beginner, they have more to gain from just building and developing that aerobic system by easy mileage. And of course, as you get faster and towards the high end of performance, you can maintain a faster pace, you have to maintain a faster pace in order to run in the right intensity zone. So if an elite athlete went on a run with me, right, so when I go out for an easy run, I run around like five minutes per kilometer to five 20 per kilometer. If Elliot Kipchogge, world record holder in the marathon, came along and went for an easy run with me, I would get aerobic development benefits from that easy intensity and going for like a couple of hours of that intensity. That would be beneficial for me. For him though, nothing. It would not give him any stimulus because his aerobic system would not be stressed enough by that. He would probably be at like 40% of his VOTMAX or even less, I don't know. So for him, that would just be simply too easy to give any kind of training stress and certainly no training effect. So for him, that will be junk mileage, unless it's a recovery run and he's just looking to get blood flow to the muscles because he actually does run about that pace for the first one or two kilometers before a hard run. So it's like a warm-up, just getting blood flow warming up. It's not training. It's warming up. Same with like a very easy recovery day after a hard workout. It's not training. It's recovery. You're just getting blood flow. You're just moving. You're just, you know, getting the system a little going, but you're not stressing the system in any way. So in that sense, junk mileage is not real. You can go as easy as you want, almost. And that's on those days, on those recovery runs, on those very easy days. But if you want to stress as an elite athlete, if Kipchoge want to stress his aerobic system just slightly, staying at 65% of max range, he has to actually go out and run, I don't know, 350 pace, perhaps even as low as four minutes per kilometer for him, that would be slow. That could possibly still be stimulating just a, you know, just a maintenance of his aerobic system. That's fine. And that is just like a base from which he works. But the real training, the real benefit for him and an elite athlete would only be when they're on top of that sort of easy mileage, adding in real quality. So the higher up you are in the sport, the more higher in the performance realm you are, the more likely you are to risk doing junk mileage if you run too slow. Whereas in the beginning, the more unlikely it is that there is such a thing as junk mileage, even you can almost go as slow as you want, because you're still going to get some kind of training benefit from it, whether that be from your aerobic system, because you're in the right intensity range, because you're really unfit and even just walking gives you a heart rate of like 70% of max, or just because your structural system develops. And structural development is almost like training for training. You're developing your body to a point where it can handle more training. And also as you go through the range of paces, and as you increase your fitness over many years and a decade, even several decades, your capacity to perform high quality work increases. So it's almost like we could imagine that the aerobic system is like the engine at the foundation that you're developing over a lot of time. But the real sort of, you know, on top of that, you're sort of adding in this little icing on the cake, if you will, which is the anaerobic training and the threshold training, which sort of just gets you into a sharp race ability type state. But it's still the aerobic system that it's all about. It just takes less maintenance to keep it as it is once you're there, so you can get away with less mileage. Anyway, that was a long talk, but I think it was an important one. I wanted this to be a long video. If you watched the whole thing, please let me know in the comments what you think about it. And subscribe if you haven't done so already, of course. I think the key takeaway, though, for you and for anyone is just not to worry too much about that idea of junk mileage and just build your aerobic system. If you're at the high end of performance, you probably already know this, right? You don't need me to tell you. Of course, if you still need me to tell you, you can always contact me and I'll explain it to you more specifically to you because it is slightly different how it applies to high-level elite athletes. But for most of us at this point, just developing the aerobic system is what's going to give us the most gains, which means that worrying about junk mileage is probably going to be quite counterproductive. Speaking of which, it's 12 o'clock almost. It's going to be a thunderstorm in three hours and I need to go out and get in like a 90-minute easy run, just developing that aerobic system. Tomorrow I have a track workout where I'm going to work on my Via2Max, but today is more of an easy semi-medium-long, just one and a half hour or something like that kind of run. I want you guys to go and check out my Strava, of course. I post all my training there. There's a link in the description. And I also now offer coaching for runners of all abilities and levels on my new website, mgjcoaching.com. There's a link in the description. You can go there. I sell customized training programs, online coaching, whatever you want to sort of help you optimize your training towards your goals. So check that out. Thank you so much for watching. Any questions you have, send me an email through the website I just mentioned. Send me a message on my Facebook page, anything like that. I'll be happy to answer it for you. And I wish you all happy running. Thanks for watching.