Do you need 3 hours of Zone 2 cardio a week if you're already strength training over 40?
You've heard that Zone 2 builds your mitochondria, burns more fat, and adds years to your life, as long as you put in about 3 hours a week. I put those claims under the microscope and compare Zone 2 with harder cardio, with a focus on what you need when you already lift and don't have hours to spare.
You'll learn:
Who Zone 2 was originally built for, and why that matters if you lift
How much to trust the heart rate zones on your watch, and the simpler test I'd use
What a 30-year Harvard study found about moderate vs. vigorous exercise
Whether adding cardio cuts into your muscle and strength
My 5-part minimum cardio plan for 3 or 4 lifting days
If you want the health benefits of cardio without giving up your lifting time, hit play.
Get 20% off Fitness Lab, my AI coaching app that builds your training around the time you have and adjusts it to how you're recovering. Learn more at witsandweights.com/app and use this special link for 20% off:
https://bit.ly/fitness-lab-pod20
Timestamps:
0:00 - Do you need Zone 2 if you lift weights?
2:53 - Where Zone 2 came from
6:02 - Fitting cardio around your lifting schedule
8:21 - Heart rate zones, wearables, and the talk test
9:21 - Mitochondria, fat burning, and longevity
14:16 - Does cardio hurt your lifting?
17:00 - A minimum effective cardio plan
22:43 - Bonus: splitting your walks for blood sugar
Episode Resources:
Episode 511: belly fat, cortisol, and the walking trial in postmenopausal women
Episode 507: carb cycling and the difference between burning fat and losing fat
Episode 374: the adaptive cardio pyramid
Episode 443: strength training and endurance after 40
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Do you need Zone 2 if you lift weights?
Philip Pape 0:00
If you lift weights and you've been told you also need three to four hours of zone two cardio every week to protect your cardiovascular health, your mitochondria, your longevity, this episode is for you. Today I'm evaluating those zone two claims for those of us who lift weights, who want to prioritize body composition and living longer. You'll learn why the experts who even defined zone two wrote that the evidence for it is somewhat lacking, why heart rate zone and your wearable may not be as reliable as you think, and how much cardio you need when you're already lifting three or four days a week. Welcome to Wits & Weights, the show that puts a popular piece of fitness advice under the microscope, finds the hidden reason it doesn't work, and gives you the deceptively simple fix that does. I'm your host, certified nutrition coach, Philip Pate, and I want to talk about zone two cardio and cardio in general today. Zone 2 is a trending topic, but it's there are good and bad reasons that we care about it. I really want to break those apart. Zone 2 is what I'd call easy, steady cardio where you can still hold a conversation. And there's a lot of promises or claims that if you do it for a few hours a week, it's going to build your mitochondria, it's going to teach your body to burn fat, it's gonna add years to your life. Peter Atia, the famous Peter Atia, he did a lot to popularize zone two cardio. And he has said that about three hours a week is the minimum for most people. Now, if you are lifting three days a week or four days, and you have a job, maybe kids or aging parents, you have a lot going on, like I do. And that's a lot of hours on top of your training. So I always like to get practical and say, what do we need? What do we want? What can we fit in, and how do we optimize our schedule to make, you know, the right things work for us from a fitness perspective? So the question is that we're trying to answer is hey, do I need to add three hours of zone two or some sort of cardio to my lifting? Do I need to do cardio at all? Do I need to do more cardio? How intense is the cardio? We're gonna cover some of those today, or most of those today. Now, two weeks ago in episode 511, I talked about a trial where postmenopausal women who walked brisky, briskly for a little over three hours a week lost the most deep belly fat. Go check out 511. We talked about belly fat and cortisol. And if you if you take that on its face, you're you might be thinking, okay, now I have to do three hours of that. And now we're gonna talk about today is three hours too much. We're gonna tease apart walking from moderate and vigorous cardio because there's different categories we can put these in. And some of them are more, let's say, sustainable than others to include in your life. So what's what's the biggest bang for your buck? Stick around to the end because then I'm gonna share a simple way to split up your walking if you care about your blood sugar and some potential other benefits when it comes to, hey, how do we actually structure our walking as
Where Zone 2 came from
Philip Pape 2:53
we get older? So, first we're gonna look at where zone two came from in the first place. Then we're gonna get into whether it's it's more important than harder or more intense cardio or more beneficial, whether cardio interferes with your lifting. We've covered that topic before, but we'll touch on it again. And then I will give you a practical, uh minimum viable cardio plan that gives you the the biggest benefit for the least amount of time if you are also lifting weights, which you should be lifting weights, roughly probably three or four days a week for most of you. So, where did this come from? Zone two comes from elite endurance athletes, cyclists, rowers, runners, who they do a lot of their training, probably 80% of their training at an easy pace. Easy for them, but an easy pace. Now, those athletes train a ton. They train 20 hours a week or more. And so when you do that, of course, a lot of it has to be easy by definition because otherwise you're going way too hard, you can't recover, you're prone to injury, uh, you're prone to just being way too stressed out. And we've seen that with folks that have been on the episode on the on the show who talk about concurrent training, hybrid training, or elite endurance athletics, that you know, the most success that a lot of these guys have found, especially as they get older and become master's athletes, is to do less. Less in terms of, you know, a lot of easier level training to maintain the fitness and then occasional bouts of the higher intense stuff. Now we have a researcher, a physiologist, his name is Inigo San Milan, and he works with Tour de France cyclists. And he showed that pro-cyclists burn more fat and clear lactate better than regular people, which, come on, of course, they're they're pro-cyclists, they're in a class of their own. So, of course, fit people tend to have better machinery in their body, you know, better metabolisms, let's say, more efficient machinery. And we can't necessarily apply that one-to-one to the rest of us. Now, the reason I mention San Melan is he went on Peter Atia's podcast. And that whole idea of zone two, based on looking at procyclists, kind of took off as this prescription for everybody, for you know, the 50-year-old Joe Schmoe who lifts on Monday, Wednesday, Friday. So just kind of keep that in back in the back of your head. Now, what is zone two? Well, this is where it gets a little bit messy. Last year, a panel of experts, mostly in the world of procycling, it was basically like 12 men, I think, in procycling. No, they weren't focused on older adults. It was specifically on these types of athletes. Okay. And they defined zone two as just below your first lactate threshold. Yeah, I know we're all going out and we're like, I'm gonna measure my lactate threshold now. Uh kind of like continuous glucose monitors, we're gonna measure that. No, don't do that. But that is roughly 70 to 80% of your max heart rate. And they prefer sessions longer than two hours. So this isn't us. I mean, unless you're going to sign up for two-hour sessions of cardio, God help you, you know, that's not for us. Now, when we think of time, that is a huge factor for us, dear listener, you and me, probably in our 40s, 50s, 60s, trying to fit in cardio around lifting instead of the other way around, in my opinion.
Fitting cardio around your lifting schedule
Philip Pape 6:02
That is what we're trying to do. Now, real quick pitch here. I have an app. I have an app called Fitness Lab that is based on this philosophy because I've run into this problem myself personally and with clients and members for many, many years. How do we, as regular people with chaotic lives, make it all fit where you don't have a personal coach trying to like play Tetris with your schedule for you? So I tried to solve that problem where you look at things like, okay, how many days can I train? How long are my sessions? What is my balance between lifting and cardio? And how do I get the most out of that? I mean, I personally, right now, am training three days a week because I'm just so busy and I want to prioritize sleep and other things that I need to figure out how do I do that, but still get enough volume over the week and still have enough time for other forms of cardio, keeping in mind that your lifting itself checks part of the box of quote unquote cardio, though maybe not all of it, but quite a bit of it along with your walking. We're gonna get into those details in a second. But you know, going back to the problem I was trying to solve with my app, and I only mention that because it's the same problem we're trying to solve when we discuss this topic, is okay, if you're able to look at your morning energy, your sleep quality, your sleep quantity, your recovery ability, whether you're run down or not, how's your immune system? Like, how are you feeling? And kind of take all that data. Hey, you could plop it into AI and try to do that yourself. Or, you know, we did that for you with our app Fitness Lab, which you can check out at witsandweights.com/ app. It is pretty cool. What it does is on train days, it lets you figure out how you should train based on all those factors. And on rest days, you could just take a rest, or you can do some sort of uh walking, mobility, breathwork type of routine for recovery. It tracks daily steps, it tracks your strength, all that other stuff, strategic cardio, all of it. So if you're looking for like a coach in your pocket to do all this, learn about it at witsandweights.com/slash app. But then you, dear listener, have a special link for 20% off in the show notes. It's not on the website. So use that if you decide it's right for you. All right, now I wanted to make that, I wanted to put that out of the way because this whole discussion about zone two is really going to be based around schedule, preference, and recovery. Okay,
Heart rate zones, wearables, and the talk test
Philip Pape 8:21
how do we get the most out of this? Well, the panel that wrote about zone two that I mentioned earlier also said that the evidence is still lacking, that a little above or a little below zone two probably gets you the same thing, meaning it's kind of fuzzy, right? It's kind of fuzzy, like the actual zone two itself is kind of an artificial construct. And then when you have your watch, let's say your Apple Watch or your wearable, many of us, it'll either tell us that we're in zone two or it'll use a heart rate formula like 180 minus your age. The problem is, again, when researchers actually measured people's real thresholds, they found it could be anywhere from 60 to 90% of your max heart rate. So there's this huge range where it might even be difficult to tell you that you're in zone two, let alone if you're taking medication like a beta blocker or what have you. So I would actually not even try to use gadgets for zone two. I would use the talk test. If you can talk in full sentences, but wouldn't want to sing, you're close enough. You're close enough. A strap wearable isn't really going to make that any more precise for you. So zone two is fuzzy, fine.
Mitochondria, fat burning, and longevity
Philip Pape 9:21
The bigger question is does it do what it claims compared to other forms of cardio or more intense cardio? So we have Martin Gabbala, who's probably done more research on interval training than anyone, review the evidence with his colleagues last year in a paper called Much Ado About Zone Two. Okay, I love titles like that. And they found the evidence doesn't show zone two is the best intensity for your mitochondria or for fat burning. Now, to be fair, they also admitted that very few studies have tested zone two the way that we describe it in popular media, the literature, or not the literature, uh social media, et cetera. So it hasn't been shown to be better, which is different from being shown to be worse. So absident, again, absence of evidence is an evidence of absence. And then you have to look at who has a horse in this race. All right. Gabbala, he's built his whole career in intervals. Sam Milan has a business tied to lactate testing, blah, blah, blah. So we look at the data. We try to look at the data. So I want to talk about mitochondria, fat burning, fitness, and longevity. Okay. For mitochondria, the research is mixed. Some data says total volume builds more mitochondria. And by that argument, the easier cardio is probably a good way to go. It's sustainable and you can do a lot of it. I think that's fair. If you have a lot of hours a week, time's not an issue. That's a totally great approach. But if you're lifting three, three or four days a week, you have a job, time is short, you're busy. Well, maybe intensity is more something we should look at because it gets you more per minute. And when I say intensity, that could be as simple as walking faster, walking uphill, putting on a rucksack. It doesn't have to be doing more intense or even hit type cardio. Just put keep that in mind. Now, what about fat burning? Well, zone two in the literature helps untrained people burn more fat during exercise. But so does intervals. And so does really anything where you're doing more than doing less. Guess what? You're burning more calories, you tend to burn a few more calories because you're moving faster or more. So that's not really a shocker. And remember, we talked about this on episode 507. Burning more fat in a certain period of time from your activity or workout is not the same as losing body fat. That still comes down to your net energy balance. There are many, many of you out there who might burn more fat because you're, I don't know, fasted training or, you know, doing an exercise session, but then you eat more later in the day. And so it doesn't matter. Like, and also if you eat a bunch of carbs before you work out, you're gonna you're gonna actually use the glucose and burn less fat, but you're still gonna burn the same amount of calories. In fact, you might burn more calories based on some research, you know, a tiny bit more, maybe. Now, what about fitness, like VO2 Max, which is kind of a fuzzy. I think VO2 Max is a good proxy for fitness in terms of comparing totally sedentary, unhealthy people to everyone else, but not as much when you get higher and higher, right? I think there's other things we can measure that are more direct, like speed and power and uh recovery and all this heart rate stuff. It's a lot easier to measure in terms of fitness, but we do know there's a high correlation between very low VO2 max and like moderate or higher VO2 max, with you know, healthy people versus bigger or more obese people that have harder metabolic problems. And of course, then that's linked to how long you live. So, speaking of that, speaking of longevity, the best long-term trial we have looked at people in their 70s for five years. So nice longitudinal trial. The interval group had half as many deaths as the moderate cardio group, but the difference wasn't what they call statistically significant. So maybe it leans toward the higher intense exercise, maybe, but again, it's hard to tell. Now, the next finding is the one I want you to take away from this whole episode. If you remember nothing else. And this was a Harvard study that followed a ton of people, more than 100,000 adults for 30 years. And moderate exercise got people the same longevity benefit as vigorous exercise. It just took a little more volume. And if you want to be specific, it's 75 to 150 minutes a week vigorous or 150 to 300 moderate. Now, that 150 is probably something you've heard about, the 150 minutes a week, because it's like right between the two, which means you have a lot of flexibility. So if you think about that, easy cardio clearly works. The question is how efficient are you with your time? How intense are you able to go? What's sustainable, etc.? And this is where we can get into things like sprinting and maybe even hit. Like I'm not totally against hit, but we're gonna talk about practical takeaways in a bit. So the popular narrative is zone two is like the optimal intensity. You gotta get, you know, three hours a week, and the the evidence says, hey, zone two is just one good tool among several. It's just a way to kind of know how intense you're going. I don't even think it's that valuable, to be honest. You know, I really don't. Having some level of cardio in your week at some level of volume is gonna be better than none at all. And probably having a lot more than that isn't gonna help you either. So guess what? Moderation is key yet again.
Does cardio hurt your lifting?
Philip Pape 14:16
So now let's get to the worry I hear from a lot of you all the time, which is okay, if I add a certain amount of cardio, can I add too much where I'm gonna affect my muscle or strength, my recovery, my lifting? All right. So when we look at pooled studies, meta-analysis, the the general consensus from what I've seen is that adding cardio to lifting is not gonna really have any negative effect on strength or muscle growth. It might affect your power, like jumping. This is what's been researched directly, but that's usually when the cardio and lifting are in the same session. Running also seems to interfere a little more than other modes like cycling, probably from the impact and the pounding. So, for most of you, taking all this together, sensible cardio isn't gonna do anything to your lifting in a negative sense, other than if there's a cost on your time or your recovery or your joints. Okay, so I would keep cardio away from your lifting if you can by a few hours, if not a different day. I would keep it away from heavy leg days. Partly, let's be honest, partly so you're not running, walking around sore all the time. Where, hey, if you're in your 50s or 60s, like one of the issues is you fall and you break something, you hurt something. If you're strong, that mitigates most of it. But also if you're recovered, that helps too, right? Like we don't want to be walking around all floppy and sore, even though we're I don't know if you guys can identify with this. I always think, okay, I'm this strong guy who who lifts weights. And sometimes I'm just so beat up, I'm like, I'm weaker than the sedentary person next to me, right in this moment, just because I'm so sore and not recovered. We don't want to be walking around like that. Now, for those of you impairing post-menopause, I always like to mention if there's anything different. Well, first, heart disease risk tends to be higher during the transition of menopause, um, independent of getting older. So cardio fitness is important for for you, but it's important from everyone. And and a lot of people don't talk about the fact that heart disease is the number one, you know, risk of death for women is very, very important. But you know, we want to lift for our muscle and bones. We want to do some cardio for our overall health. But again, we're gonna talk about how to do that. Okay, I don't want you going out and doing three hours of uh intense training every week. You don't have to do that. The other thing is you've probably heard that HIIT training, okay, high intensity interval training raises cortisol and you should avoid it because of that. Well, we went through cortisol in episode 511. A hard session of any type of training, lifting weights, you know, fast walking, HIT, whatever, is gonna raise your cortisol for a short time. The same way it raises your heart rate and your blood pressure. That's totally normal. And it's actually a good acute stressor that leads to long-term lower stress. So don't think that interval training is this terrible thing and it harms, you know, anybody, any population, including, you know, women in menopause or whatever. If you're sleeping terribly, if life is chaotic, well, then you have to say, okay, I need I might need to dial things back, but that's a dose issue. And all of this is really a dose issue, going back to my comment of moderation. So, what do
A minimum effective cardio plan
Philip Pape 17:00
you do? Let's let's talk practical terms. Well, if you lift three or four days a week, you have a life. I hope you do. I hope you're enjoying life. I hope you want to do all the other fun things that outside of the gym that fulfill you, and you want the health benefits of cardio, but not compete with your training. Here's the plan I would use. Okay, number one is aim for those guideline amounts, which I mentioned earlier: 75 to 150 minutes a week of intense or hard cardio, or 150 to 300 of moderate or a mix. Now, I would count lifting weights towards some of that time as a proxy. I just do. I do. It's not all of your cardio, but it's a massive contribution. And we know that a combination of lifting and cardio is tremendously beneficial for longevity. And you don't necessarily have to have that like 300 minutes of cardio on top of your lifting. So it's there's kind of an overlap, is my point. But if you're trying to make maximize your time, having some harder cardio in there, and that's up to you what that means. It's a sliding scale. That could be, you know, just walking briskly or putting on a rucksack more often now than you did in the past, walking on an incline. It could be a little bit of a medium intensity cardio on a bike, right? Or stair climber or rower, or I like things like uh prowler or sled pushes or pulls as well. Really nice. Great for your health if you can fit it in if you have the equipment, if you have the access. So that's number one. Number two is fit in one uh sprint session a week. Now I was gonna say intervals, it's kind of ambiguous. I'm not a big fan of certain hit protocols like Tabata and whatnot. I did a lot of those back in the CrossFit days. You just want to be careful, and there's there's joint issues and things you gotta watch out for, form and stuff like that. I would just say, hey, warm up for five or 10 minutes and then do the sprint protocol we talk about all the time, which I completely stole from Brad Kearns. Okay, four to eight sets or rounds of all-out 10 to 20 second sprints, where the recovery time is six times as long as the uh work time. That's it. And that takes about 15, 20 minutes total. You can do that once or twice a week. If you do it twice a week, that adds up to 40 really, really intense minutes of cardio and gets you like that plus lifting honestly probably gets you there if you're getting enough steps. Like if you're getting enough steps, because to me, the steps count toward the moderate cardio as well. And then number three is if you've got the time, if you have the inclination, if you want to maybe burn some more calories and increase your health just a little bit more, add one or two easy sessions. Now, when I say that, you you might be thinking this is like the grinded out cardio. Doesn't have to be. This could be just more walks, more brisk walks, like I mentioned before, that gets you into zone two. But I don't think you need to gadget for the zone two. I think, look, for me, if I walk four miles an hour, I'm like really walking fast where I just, you know, can barely hold a conversation. I know I'm there in that realm. And if you don't like that, there's a million other ways to fit in cardio. A lot of you play sports too, do things for fun. You know, if you love walking, if you have the time, three hours of walking, four hours of walking a week is great. You figure a mile takes about 20 minutes, it's about 2,000 steps. So you maybe get five or 6,000 steps in an hour of walking. So even if you walked, so if you walked an hour a day total, that's you know, a good chunk of your steps, and that's deliberate walking, right? Hopefully, many of you are taking the stairs, you're parking away from the store and your workplace, you're pacing around the house, and it all starts to add up to the other several thousands of steps every day. Number four is I would pick cycling on a like an air bike or a rowing machine, like uh what do you call that? The the C2, uh man, I'm is that the C2? Man, my mind is going blank, but you know what I'm saying. Uh stair climber, elliptical, incline walking on a hill or treadmill. I'd pick any of that over running if recovery and longevity are you know your most important thing. So lifting weights, you know, you protecting your joints, recovery, stress, all that stuff. I'd keep that hard cardio at least two or three hours away from heavy leg training at least. If you love running, if it is just a joy of yours and you're doing it with the right form and footwear to minimize or eliminate injury, okay, go for it. I'm not gonna stop you from doing that. Maybe keep it off of your squat days. Okay. Number five is you can sprinkle in snacks throughout the day. And I don't want to talk about food snacks. I'm talking about high-intensity uh exercise snacks, like taking the stairs fast or running on the stairs. You know, just a little bit of that throughout the day tends to be linked with people living longer where they don't do formal exercise. Now, you do formal exercise, but so think about how you balance that in. But it's a fun thing to throw in. So for many of you, this is just like the pyramid we talked about a long time ago, the adaptive cardio pyramid, where in the bottom of the pyramid is get your walking in, then you have your fun cardio, then you have your intentional sessions, and then you have like a sprinter to a week at the top. So you're basically lifting things, you're walking, and occasionally you are sprinting or doing more intense cardio. That's it. All right, before we wrap up, I promised you a way to split up your walking in a certain strategic way that could be more beneficial. And I'll give that to you in a second. But first, I do want to say this Thursday, I have Lyle McDonald on the show. Lyle has been writing about fat loss, dieting, body composition since the 90s. And we're gonna be talking about intermittent modified fasting. Now, this is built around trying to lose fat rapidly without losing muscle for people who train. We're not talking about intermittent fasting, we're not talking about fasting in general. It's a very specific, very good, in my opinion, protocol. And Lyle has a unique personality, he's not shy with his opinions, a fun episode. If you're not following the show yet, hit follow now in your app. Hit follow. And if you know others who like like Lyle, forward this to them so that they can catch
Bonus: splitting your walks for blood sugar
Philip Pape 22:43
that as well. All right. So if you walk for your health, which every single one of you listening should be doing, you should be aiming for something like seven or eight, thousand steps or more a day. How you split up that walking could give you extra benefits in addition to just how long or how many steps you get. There was a small study. It's a small study, but it's adults in their late 60s who had borderline high blood sugar, and they split them into two groups. So they walk 45 minutes a day, either all at the same time or split into three 15-minute walks, starting a half hour after each meal. So, like breakfast, lunch, dinner, then half hour later go for a 15-minute walk, versus just go for one long 45-minute walk. Well, not surprisingly, the three short walks lowered their blood sugar across the whole day by about 10%, and it blunted the blood sugar rise after dinner. Whereas the one long afternoon didn't affect those numbers the same. Now, we've talked about in the past that acute blood sugar uh fluctuations are not an issue at all if you're healthy, if you're lifting weights, if you're moving, but there could be, you know, slight longevity benefits here by splitting up your walking, but there's other benefits like keeping you moving throughout the day, making this a good habit. There could be benefits to your, what am I trying to say, appetite and digestion and all these other, there's all these other little side benefits I find from people who tend to walk multiple times in the day versus just trying to have like, okay, here's my lifting session, here's my walking session. So just think about it. Okay. Until next time, keep using your wits, lifting those weights. And remember, you don't need three hours of zone two on top of your lifting. For most of you, a hard cardio session a week and a lot of walking, plus your lifting covers all of your health opportunities. I'm Philip Pape, and I'll talk to you next time here on the Wits & Weights podcast.
