What If Zone 2 Running Is Slowing You Down?

[00:00:00] Low heart rate training, easy running and zone two efforts. If you’ve touched distance running YouTube or listened to a health and fitness optimization podcast lately, you’ve heard about it, it’s everywhere. The scientific data tell us that we should all be getting anywhere from 150 minutes to 200 minutes per week minimum of zone two cardio.

[00:00:19] We’re starting with just a zone two training protocol. As they slowed down over time, as the weeks went by, they would race faster. But then I listened to a podcast that goes deep on a huge scientific narrative review of zone two training, and basically says there is no evidence that zone two is the magical zone for overall health and fitness for the general population.

[00:00:41] And it got me wondering, is zone two actually as effective as everyone says, or have I, and maybe you. I’ve been overdoing it this whole time. Here’s what I’ll be going over what zone two really is and why it’s kind of a mess to define what the science actually says about its effectiveness, especially if you’re not elite.

[00:00:59] Why most real people, general population can’t train like pros, even if we want to. How I’m rethinking my entire relationship with zone two and a free download that helps you build a smarter training week that won’t wreck your body. I’m Daren D Lake, a run coach, and former sprinter. 30 years ago, I was focused on speed, but for the last 15 years, I’ve been a zone two addict using it to complete a sub three hour marathon and 10 hour Ironman.

[00:01:23] Now I test smarter ways to get 1% better each day, and I wanna show 10,000 runners how to do just that. Let’s get into the episode. Zone two is what most people call the easy zone. Roughly 60 to 75% of your max heart rate, or what many define as below or up to your first lactate threshold? A KLT one, which I did a whole series, multiple episodes on.

[00:01:44] The link is above or below in the show notes, but here’s the thing. Zone two is not exact. Depending on whether you’re using three zone, five zone, seven zone heart rate model, the boundaries shift. Most amateur runners can’t do a finger prick lactate threshold test on every run. So some people use heart rate, some use pace.

[00:02:02] Some go by effort of feel some mash ’em together. I actually mash ’em all together to get zone two. That vagueness. It creates a problem because if you’re only training three to four times a week and you’re spending all that time in this easy but not quite easy enough bucket, you might be doing just enough to feel like you’re training, but not hitting the stimulus and the adaptation and the stress that you need to actually improve and get faster.

[00:02:24] My zone two. Is actually at about 78 to 81% of my maximum heart rate. Zone two. Cardio for sake of cardiovascular health, cerebrovascular health, and a number of other aspects of health that are important essentially to everybody for healthspan and lifespan. Well, last week’s, not fibers, more glycolytic, more lactate, more C two.

[00:02:46] So it seems old school. But it works beautifully. These are smart people. I bought into it for years, the last 12, 13 years, and I still respect them. But then I went deeper on that narrative review of zone two by Kristi Storchak, published in May of 2025, and one line stuck with me. The evidence does not unequivocally support zone two as uniquely benefiting mitochondrial health.

[00:03:09] Boom. So what does the research actually support, especially if you’re not an elite athlete? Here’s what’s interesting. When you look at the research on time efficient training sub-threshold running that’s low zone three and targeted zone four slash VO two max intervals, they often deliver faster results than pure zone two, work faster.

[00:03:28] Asterisk. Get to that in a second. Quick run Science nerd break a 2021 meta-analysis. So many studies by Melvic looked at 47 studies. The finding high intensity interval training improved VO two max more effectively than moderate intensity AKA zone two continuous training and in less time. So here’s an analogy.

[00:03:47] Think of your aerobic system like an engine zone. Two fine tunes. It makes it efficient at burning fuel. Zone three, that’s like adding horsepower with a small turbocharger. Same fuel system, but now you can sustain faster speeds. Zone four, that’s a supercharger with even more horsepower. This research wasn’t done on elite runners.

[00:04:05] It focused on general population training and mostly amateurs in sedentary non-active people. So non-active non FITT runners. If you cycle row, do hit cardio classes, CrossFit, swim, et cetera, you can often handle three to four high intensity sessions a week. Your cardiovascular system recovers quite quickly, but running.

[00:04:25] Running ads impact to your musculoskeletal system. Your heart and lungs might bounce back overnight, but your joints, tendons, ligaments, and bones adapt much more slowly. Sometimes taking a few months versus two to three weeks for cardiovascular fitness gains. So when you get your heart rate up, you come back, you’re like, I’m fit.

[00:04:41] I feel good. My lungs are fine, but. Your body is like, nah, that means higher risk of developing an overuse body injury, even though you’re breathing fine and you feel great. That’s why runners need to be more strategic about running intensity than other endurance athletes. Injury is a much higher risk the faster that you’ve run.

[00:04:59] So what’s the option if you’re training three to four times a week and you still want to improve? Here is an example training plan. We’ll break this down practically, so I’ll put this table up here really quick. We got three types of runners. You got elites, you have fake pros, me sub elite, kind of fast, but not fast enough to be pro, and you got real people with real jobs that run.

[00:05:18] You know, four or five, six hour marathons, they run hour 45, 2 hour half marathons, et cetera, 25 minute five Ks, et cetera. I’m gonna put myself in that fake pro bucket. So elites, they’re about 160 Ks a week, a hundred miles, and their common mistake is overload, but it’s recoverable and the smart fix. 80 20 works because they have hours that 20% of doing hard.

[00:05:39] So 80% easy, 20% hard. The 80 20 rule, that means that that 20%, they’re actually getting a lot of zone three, zone four, even zone five work in now. Sub elite people, AKA fake pros. 80 to a hundred Ks a week is the weekly volume that’s 50 to 60 miles. Uh, too much meh. Zone two, you probably get a decent amount, but probably not a lot.

[00:05:58] And burnout without adaptation can happen. So you can do too much zone two running. Once you start getting fast at running zone two, you actually start wearing yourself out and your body doesn’t recover even though you’re running slow and comfortable, your body actually is getting stressed. That happened to me in my last marathon box.

[00:06:13] And then the last group is uh, real people out there. It’s calling you real people. And 30 to 50 Ks a week, that’s 15 to 30 miles. Common mistake is no intensity, no structure, and a smart fix is that you need precision and minimal intensity. This, there’s asterisk to all this ’cause everyone’s different. But here’s a solution, a smarter for run structure.

[00:06:32] So four days a week, that works for most people. You wanna do one genuine high zone, two 30 to 45 minute easy run a week conversational easy pace with a fast finish where you get into low or mid zone three for the last five to 10 minutes right before you cool down. Then you’ll have one sub threshold tempo, run comfortably hard.

[00:06:53] That’s where you’re definitely in zone three, low to mid zone three, uh, but sustainable. So the threshold, again, I did the episode on that, check that out below. Get that link to know where your threshold is, et cetera. And then the third run would be. One short interval session. So we’re gonna get into VO two max reps, so zone four, hill repeats, track work, et cetera.

[00:07:13] Really get your heart rate quite high, about 90 to 95% of your max heart rate if you wanna go by heart rate. And then one long run, which is mostly high zone one, low zone two, very conversational, easy pace, even easier than that high zone two run that we did. That’s gonna be your bread and butter. All you need is those four days.

[00:07:30] If you only got three days to run. Here is a variation. One sub-threshold run, same as the four days a week, comfortably hard zone three low and mid zone three, one short interval session. Again, VO two max reps, and you only will have then time for one long run, but instead of doing high zone one, low zone two, so very, very easy.

[00:07:51] It’s gonna be more of a. High zone two run. So conversational, easy pace, but you’re getting it with a nice clip and you have a fast finish at the end. So the last 10 to 20% where you’ll get into low or mid zone three. Quick run science nerd break A 2018 study by SER and Tosin found that adding just one weekly threshold session improved performance in well-trained athletes without increasing injury risk.

[00:08:13] So here’s a quick analogy. Again, zone two is like. Cooking pasta at a gentle simmer. The water’s moving but not bubbling much. It’s sustainable and steady. Zone three is where the water starts reaching a rolling boil, so you can see the bubbles in there, more energy still controlled, and some zone four high intensity intervals.

[00:08:28] They might touch that and it’s like turning the heat to maximum pasta water vigorously bubbling and almost spilling over. And then you hit zone four, zone five, and the pot spills over with the pasta and you put out the flame and then it almost. Creates a big mess and you almost got a fire, et cetera.

[00:08:42] You don’t want that. So we really wanna stay in that, like water simmering. And then water is kind of, you see, bubble zone two, zone three area, the key precision over volume. Most recreational general population runners can’t absorb the same training. Stress as habitual cardio class goers, cyclists, CrossFit swimmers, et cetera, because of the impact factor on your body, the musculoskeletal system.

[00:09:05] So what’s the plan? How do we actually build all of this? My free guide shows exactly how to mix zone two, sub-threshold zone three, and high intensity zone four, without overthinking it. It’s built for real life runners with real lives and limited time. You can download it, use it, and then let me know what changes.

[00:09:23] Get it at the QR code link below or in the show notes of your podcast players app. If you’re listening, let’s get back into the episode. This isn’t just about running physiology, it’s about mental models and in particular your belief systems. I went all in on zone two for the last, almost 14 years after reading Dr.

[00:09:41] Phil Mafa tone’s Big Book of Endurance, which I still love to this day. Gave me such a great framework and it helped. I improved. Crazy amounts. The runners I coach go faster and healthier. I literally was the 800 meter runner, the the mid-distance guy back in my track days, 20 plus years ago that had no aerobic base.

[00:09:59] Started doing distance running about, yeah, 13, 14 years ago. Had no aerobic base and I just worked on it, hammered it. It was boring and it worked. Now I have a crazy engine. I don’t use actually enough of my threshold and VO two max system, which I’m now working on. But that wasn’t because zone two was magic.

[00:10:14] It was because. I was consistent and the runners that I coach were consistent and progressive, so I was consistent showing up. That’s what did it. The thing is different races demand different approaches for shorter races, like five Ks, 10 Ks, and even half marathons. The primary demands and the needs are speed, lactate, threshold, lactate tolerance.

[00:10:33] Mvo two max. These adapt best to threshold work and intervals, not just mileage. If you wanna know more about those lactate threshold, elastic tolerance, how to train for 5K, 10 k. I did a whole episode on 5K. Go check that out. Appear or link down in show notes. But for marathons, ultras, and long triathlons.

[00:10:49] Zone two and the 80 20 approach still makes sense because you’re putting the time in. So you have the privilege to be an adult with extra time to go out there and spend 10, 15, 20 hours a week training when your race is three plus hours, five hours, 10 hours, Ironman, 15 hours Ironman. You need that aerobic base and fat burning efficiency that comes from sustained.

[00:11:11] Zone one, zone two, easy volume. It’s not that zone two is bad. It’s that most people are applying marathon training methods to 5K Park run goals. Belief in your training approach is incredibly powerful. It can be the difference between sticking with the program or totally abandoning it, which is why I’ve dedicated entire section to mental models.

[00:11:29] In my upcoming book, the 1% Better Runner, all about belief, patience, consistency. And focus more details on that. Soon out of the lab and into the coach’s office as we’ll say coaches are split on this review. Yes, well-known coaches and that is so good and it’s so useful. We want both sides so you can make an informed decision in the middle.

[00:11:49] It’s like getting two opinions when you go to two different doctors with specialists. So on side A over here, the pushback against his narrative review, Steve Magnus. Steve Magnus, a coach, author. He thinks that the hot takes missed the long game. Most studies are short that they’ve reviewed in this narrative review four to eight weeks intervals.

[00:12:07] They work very early. If you’re unfit and it’s early in your training and you go from not fit to very fit very quickly, but over months, that easy aerobic work compounds. Capillaries, mitochondrial density, that’s in your heart, durability. So basically the pathway of blood gets bigger. I’m making a very, very simplified, oversimplified analogy.

[00:12:27] The pathway of blood that goes from your heart to your muscles and everywhere else. You make that bigger. You make the roads bigger so it’s more efficient. His big idea, you can’t microwave aerobic development. And I’m going to agree with that because after 13 years, it was actually more like six or seven years, 13 total Now.

[00:12:44] My zone two is crazy and I love it. I love it. I can run very fast In zone two alone, zone three, it’s phenomenal. Also, the best training blends, intensities. We need it all as endurance runners, as distance runners. Not all easy, not all hard and integration. Zone one, zone two, zone three, zone four, zone five, all of it.

[00:13:00] And a time horizon matter. So you need to zoom out and then do it over the long haul and not get injured. Do not die. In other words, polarized or pyramid based training. Not dogma. Here’s a quick analogy. Intervals are espresso sharp, jolt easy. Volume is a slow drip that fills the pot for one cup. Espresso wins for household, the pot wins, and on side B over here.

[00:13:25] Co-signing that the narrative review is somewhat right is Adam Raper. So Coach Adam Raper, based in California, coaches many mid distance and distance kids in high school lands. Closer to this review, he sees that the best mitochondrial bang comes near lactate threshold, so sub threshold at the top of the aerobic zone, high zone two, low zone three.

[00:13:45] His playbook, lots of LT lactate threshold steady and actic threshold intervals, dosed precisely by heart rate or occasional blood lactate prick. What you need. So think 10 30. 10. So lactate steady 10 aerobic. Uh, mid zone two, then 30 minutes at your low to mid lactate threshold. So that’s about zone three, and then 10 minutes aerobic.

[00:14:06] Again, back it down to zone two, or you could do four by four minutes to five by five minutes, and then you have short rest. You have 32nd rest, one minute rest. You can do these in a lot of different ways to get up to lactate threshold with long. Aerobic floats in between. So you keep the zone too high, you, you drop back down to like half marathon marathon pace, then get back up to like 10 K pacing, then you back it down or 5K pace even then back it down.

[00:14:29] He caps lactate threshold minutes at 30 minutes for up to 10 K runners and avoids threshold pace guessing. ’cause he wants to stress the quarry cycle, which is clearing and recycling lactate without tipping over. I’ll go into more detail on the quarry cycle in a future episode. Comment below if you wanna hear more about that.

[00:14:46] His take on zone two. It’s great for longevity and frequency, but for many non marathoners, it’s an inefficient middle area. It’s too easy to drive threshold, too hard to be full recovery. So. Where we agree, which takes us to C area, where we both agree on both sides. Both sides actually agree on more than it seems right in the middle.

[00:15:05] Don’t pick a side blend. Intensities, context matters. Training, age, volume, experience, and time horizon change the answer. For runners. Precise dosing will prevent. Injuries. So getting that exact pace, that exact heart rate that you want. If you want a quick TLDR summary, if you got big volume in a long runway, easy work compounds if you time crunch sub-threshold plus a touch of VO two max zone four intervals is your fast lane and you can do just that if you’re tired of blindly following what elites do and possibly want a better.

[00:15:36] Less is more type of way. Download that free three and four day training week made simple training plan so you can train smarter, not softer. You’ll also get my free email newsletter that gets you all the tools and tips every week. Write in your inbox mental strength to talk about VO two max long runs, sprints, et cetera, and it’s kind of fun.

[00:15:56] Get out the QR code here, link below in show notes of your podcast player and once your training’s in. You need to make sure that your form isn’t slowing you down. Go watch this next video on Overstriding. It might be one of the final pieces of your best finishing time running puzzle.