 Is there really such a thing as junk miles? And could riding these junk miles ruin your training? If you haven't heard the term junk miles before, it usually refers to training time that is either not useful and therefore not making you faster and fitter or potentially even detrimental and actually making you slower. This is a concerning prospect. No one wants to waste their time on the bike, but depending on who you ask, different riders have different opinions about what exactly a junk mile is. Some might say that it's when you're just noodling around and not really going that hard. Others might say it's when you're going kind of hard but not really hard enough to be considered a hard ride. And I'm sure other interpretations exist as well. Today, we're gonna dive into the science to see if there really is a type of riding or intensity that should be avoided and at what point your training goes from productive to unproductive and is better left tossed in the bin. I'm gonna guess that at the point that you actually start to have fun riding your bike, then you're doing something wrong. Seems like something this guy would say. Let's start with the first question. Oftentimes when people are talking about junk miles, they're referring to a specific intensity of training and intensity here is referring to how hard you're training. So is there an intensity that you should avoid if you want to improve? Well, this is actually the theory behind polarized training. I've talked about polarized training a number of times on this channel, but for those that don't know under strict polarized training, you would spend a lot of time riding easy, a little bit of time riding hard and very little to no time riding at a moderate pace. Under the polarized model, moderate training is what would be considered junk miles. This intensity lies in between the point at which your blood lactate levels first start to rise at 75 to 80% of your FTP and when your lactate levels spike, which is at your FTP. And if you've watched any of my videos on polarized training, then you already know that there is a good sized body of research to support polarized training as the best approach. I would say more so than any other training approach out there. Whenever polarized training is put to the test against more traditional training models, polarized almost always comes out on top. For example, it's been shown in Ironman triathletes that more time spent training at a moderate intensity was correlated with poorer race performance and polarized training has even been shown to produce better results in time crunched athletes who only have six to eight hours per week to train, which are exactly the kind of athletes that usually fall into the let's make every ride hard trap. If you're still unconvinced about the effectiveness of polarized training or you're still unclear about what exactly it is, then I've left links to videos that go into more detail down in the description below. Getting back to our junk miles question though, it would seem that if polarized training is the most effective way to train and there's certainly evidence indicating that it is, then this moderate intensity at 75 to 100% of your FTP would be considered junk miles. At best, it's a waste of your time and at worst, it's actively making you slower. However, this is where the commonly referred to tempo and sweet spot zone lie. And yet tempo and sweet spot workouts remain common amongst cyclists and other endurance athletes. This begs the question, should we avoid these zones at all costs or perhaps just limit our time in them? This is where pyramidal training comes in. Pyramidal training is similar to polarized training in that a large amount of your training time is spent riding easy, 80% or more. But what you do with that remaining 20% is where pyramidal differs, spending some time at a moderate intensity and a smaller amount of time at high intensity, essentially forming a pyramid with your intensity. Who would a guest? And while there isn't as much research on pyramidal training as there is on polarized training, the research that we do have looks very promising. For example, in this study on half Ironman triathletes testing polarized versus pyramidal, they found that both training prescriptions showed a significant positive effect and pyramidal even outperformed polarized in the running results. They state that although most of the training volume was carried out at a low intensity, moderate intensity is still relevant and should not be discarded. Further research comes to the same conclusion. Both polarized and pyramidal training seem to be the most effective and it does appear that most elite endurance athletes train in a pyramidal manner. This would seem to indicate that moderate training isn't necessarily junk miles. You can design an effective training program that includes moderate intensity in it. And I would argue that for certain athletes trained for certain events, this is actually the better option even over polarized training. What seems to be more important is your time spent at this intensity. It seems clear from the research that you can absolutely overdo it with moderate intensity training. And when you do that, your fitness will start to suffer. So if we want to get specific here, there isn't one intensity that is automatically considered junk miles. A good training plan can have a full range of intensities included in it, but the distribution of these intensities is critical, particularly with moderate and high intensity. Spend too much time riding kinda hard or very hard and this training time could absolutely be put in the junk miles bin because it's a waste of your time and could even be making you slower. So we've established that the amount of time that you spend training in these zones is important. But I would also argue that the way that you arrange these zones throughout your training is equally important. For example, let's take two riders that I made up for the sake of this video. The first rider, let's call him Rider One, doesn't follow a plan. He just kind of rides hard when he's on a climb or when someone passes him on the bike path and then everywhere else, he just sort of noodles around. Yeah, Rider One definitely f***s. Miraculously, this actually has him training in a pyramidal distribution with 80% of his time riding easy, 15% riding moderate and 5% riding hard. Then we have Rider Two, who follows a training plan and if he has an easy day, he keeps it easy, no matter who passes him on the bike path or who just stole his KOM. He also has two days in the week where he does structured intervals so that his distribution ends up being the same with 80% easy, 15% moderate and 5% hard. All else being equal, I would 100% put my money on Rider Two to make greater fitness gains than Rider One. And here's why. Though both of these riders have the same training intensity distribution, Rider One is turning on his autonomic nervous system or his body's stress response every single day or at least every single time that he rides while Rider Two is only turning it on twice a week. This is because riding above the first ventilatory threshold has been shown to act like a binary threshold for ANS slash HRV recovery. In this study, riding at a moderate intensity or riding at a high intensity produced identical delays in HRV recovery that were not observed when subjects rode at a low intensity. Essentially what this means is that this threshold that separates easy and moderate training, which again lies at 75% to 80% of your FTP depending on the rider, kind of acts like a on-off switch for your body's stress response. Stay below this point and you're keeping your stress levels low but go above this point and you've now significantly increased your stress response and delayed recovery. Now, obviously you need to stress your body in order to make improvements. That's literally what training is but significantly stress your autonomic nervous system every single day or every single time you go for a ride. And this is the kind of thing that could lead to overtraining and burnout. You may be able to get away with it for a week and feel fine but do it for a month or a couple months and you could start to hit a fitness plateau. If we go back to our example riders, rider one was turning on this stress response every time he left to go for a ride while rider two was only turning it on when it was absolutely necessary which was twice a week during his interval days. When you put it that way, it doesn't take a rocket scientist to try to figure out which rider is gonna be more fatigued after a month of training like this, even though both riders spent the same amount of time training in their respective zones. Therefore, I would throw these rides that don't really have a purpose that are completely unstructured where the intensity is all over the map in the junk miles category. Sure, sprinting randomly up a climb or going after a short KOM and then just putzing around the rest of the time may keep things fun and interesting but these rides that aren't easy enough to be an easy day and aren't hard enough to be a hard day are likely hurting your progress. See, what did I tell you at the beginning of the video? I know this guy too well, unfortunately. And this isn't the same thing as doing tempo intervals which is an intensity that's not that hard but also not that easy. You rack up a good amount of time at this intensity to induce adaptation and then you follow that up with easy days afterwards to recover. You could even combine a hard interval session with a longer, easier endurance ride so that the distribution of the ride is mixed but if you go over that first threshold then it should be considered a hard day and you should try to get the most out of it instead of just sort of half-assing it so that you feel like you did something when you get back home. So we've been spending the majority of this video talking about the gray zone between easy and hard riding and the nuances of whether or not that's considered junk miles but is there a point at which your training is too easy and while not overly stressful it is just a waste of your time? The answer is yes. Most training zone models put the top of your zone one and the bottom of your zone two around 55% of your FTP. It's been observed that very little adaptation is made when your training intensity is this low and on your endurance ride days you really wanna be spending as much of the ride as possible in your actual endurance zone at 55 to 75% of your FTP. You may choose to ride at the higher end of the endurance range if your legs feel good or if you've just got a short ride to do and you may choose to ride at the lower end of the endurance range if your legs don't feel that great or you've got a longer ride to do but if you're spending a significant amount of your ride below 55% of your FTP that probably isn't a particularly good use of your time and if you're so tired that you can't even hold above 55% of your FTP then the solution is likely recovery not to just push through it. So I'm sure the question on a lot of people's minds right now is what about recovery rides? Are those useful or not? And the honest answer is that, I don't know and that's simply because there isn't a lot of research on whether recovery rides are effective or not. Most of the research done on active recovery looks at how well it works when done between hard efforts, not done on a day that you would otherwise not ride your bike. This is a question that I asked Steven Seiler who's a leading endurance sports researcher and this is the answer he gave. I'm gonna be honest with you, if you are really tired and you really say I just want to pedal as slow as I can, then I would say well then why don't you just stay on the sofa and watch reruns or something and really rest. He did say later in the interview though that elite athletes do these kinds of rides so maybe at that level there may be some utility to it. However, I think this is an area where you can do your own experimentation. See if you feel better after doing a recovery ride or completely taking the day off. You know, I've actually done that experiment. Let me see if I can pull up the results real quick. All right, yeah, here we go. Okay, so it says that if you take a recovery day, you're a bitch, do some hill repeats, you pansy. Well, I'm just reading the results of the study. That being said, if you're gonna do a recovery ride, please for the love of God or the spirit of gravel or whatever it is that you worship, actually stay in your recovery zone the entire time and there is no need for a recovery ride to be over an hour. I would 100% put recovery rides that are two or three plus hours long and where you're mashing up a climb for no apparent reason in the junk miles category. No need for any interpretation or nuance there. Thanks for watching. If you wanna step up your training, then I have online training plans available on both training peaks and today's plan. And for a more personalized plan, I also have coaches available as well, both linked down in the description. If you enjoyed this video, be sure to give it a like, subscribe and share this video with your cycling friends. See you in the next one.