In this episode of the Flex Diet Podcast, I sit down with my friend Kristi Storoschuk, a PhD candidate in exercise physiology, to unpack her review paper on zone 2 cardio and what the evidence actually shows. We dig into what “zone 2” really means (including lactate thresholds and why common proxies like heart rate and the talk test can miss the mark), where the 80/20 endurance model came from, and why messaging around zone 2 for mitochondrial function, fat oxidation, metabolic flexibility, and health may be overstated, especially for the general population.
Kristi explains why higher intensities often produce equal or better mitochondrial and performance-related adaptations, how training volume and population context change the conversation, and where low-intensity work like walking may still fit.
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Speaker: [00:00:00] Welcome back to the Flex Diet Podcast. I'm your host, Dr. Mike T. Nelson. On this podcast, we talked about all things to increase muscle, improve performance, better body composition, and do all of it without destroying your health in a flexible framework. Today on the podcast, we've got my friend Christie Stork, and she is a PhD candidate in exercise physiology.
Published a great review about zone two cardio training, and that's exactly what we're talking about today. So a big part of her research is looking at zone two cardio. She's also looking at different components of metabolic flexibility from mitochondrial adaptations and how different training intensities affect recovery and long-term performance.
So I really enjoyed this conversation. Uh, we'll link to her previous podcast that we had here. She had some [00:01:00] great stuff there. Um, so in this one we're talking about just a little bit of how do you set up zone two stuff. What is exactly, is it, how does lactate affect it? Uh, does zones really matter? Training, kinda sort of the origins of where zone two came out.
Intensity differences. And even can talk a little bit about frequency, how you set that up, mitochondrial changes, and even some stuff on lower intensity things such as walking. So make sure to check out all of her great stuff. We'll put a link down below to, uh, her Instagram and all of her wonderful stuff.
And again, if you wanna hop onto the Fitness Insider Newsletter, I'll have a link for my stuff down below. And then we also have the Flex four. So I asked her if someone is a recreational lifter listening to this and want to get better at Aerobic Fitness, what would be [00:02:00] her Rapid fire Top four tips. So you can get that exclusive content.
If you're already on the Fitness Insider, you'll get that automatically sent to you right away. If not, you can hop on to it via the flux four down below, and you'll get her four top tips there. And you'll get a ton of previous top four tips from previous podcast guests. Uh, that content only goes out to the newsletter insider subscribers, and it's completely free to join.
So this was a great discussion. As you know, I'm not the world's biggest fan of zone two training. But what's nice about podcast formats is you get to talk to experts who are looking at this in the lab, and you get to have a long conversation to get into some of the nuances and details because like all things context does matter.
So huge. Thanks to [00:03:00] Christie for doing this. Greatly appreciate it. Um, also want to give a shout out. She will be at the International Society of Sports Nutrition Conference coming up in June. Down in Florida. Uh, I believe she'll be giving a talk there. I'll also be there, um, giving a talk. So we'll put a link to the ISSN below if you're looking for a nerdy conference to go to.
Uh, tons of stuff related to exercise physiology, definitely more on the supplementation, nutrition side. Just a really, really fun event I've been attending and presenting at the ISSN. Oh man. 2011, 2010. I think the first time I attended was like 2008, which is kind of crazy. So, uh, we'll put all that information down below.
So without further ado, here's a discussion with Christie, all about the pros and cons of a zone two training.
Dr Mike T Nelson: Welcome back to the podcast. How are you today?
Both: [00:04:00] Hi, Mike. It's a pleasure to be back honored as always, and thank you for having me. Oh, thank you.
Dr Mike T Nelson: Yeah. I'm gonna link to your previous one and today we're talking all about the awesome paper you posted and written about zone two cardio. It seems to be everything in fitness appears to be one extreme to the other.
I think we went through the phase of, oh, zone two is gonna cure everything, and now it feels like we're in the phase of. Zone two is stupid and worthless. And yeah. I wanted to have you on the podcast to, to talk about that. What made you want to write the paper that you did, which we'll link to?
Both: Well the motivation behind the paper, like you, I'm sure, is that we heard about zone two through like podcasts and the social media and.
Proponents of zone two. Back in like, I think it was like 2016 when it was starting to come out and I started to learn about it and I was like, [00:05:00] oh, well, I, it was positioned as we need to do lots of low intensity zone two training because that's where we are at our peak fat oxidation. And so if we're.
Peak fat oxidation, we should be training our mitochondria 'cause that's the site of fat oxidation to become better fat burners. And becoming a fed better fat burner improves our metabolic flexibility. And this should mean that we're really insulin sensitive and we are preventing chronic disease or maybe arming ourselves against, the chronic disease. And so I picked up on this, I listened to these podcasts and I was like, oh, well, I care about my metabolic health. I care about my mitochondria, so should I be doing zone two? Because all I do is high intensity. I'm like a ball to the wall type of exerciser, short and sweet, and.
So then I was considering for myself if I needed zone two and I started doing some long distance running, et cetera. Gave up on it very quickly. And then, but that was way [00:06:00] back, that's like almost a decade ago now. And so once I started my PhD zone two still being talked about and pushed online for metabolic health reasons to the general public.
So this was my, like my, yes.
Dr Mike T Nelson: I think that's a key distinction. 'cause that was one of my questions coming up.
Both: Yeah, so it was being pushed for just like metabolic health, like we all need to be doing zone two because we need to improve our mitochondrial function because our mitochondria is so important to metabolic health.
And yes, there's, I agree with that, but whether or not zone two is what's improving, that is what we can get to in this podcast. But essentially I brought the idea of zone two to my supervisor 'cause. I was trying to figure out what I wanted to research. I wanted to research something topical. And so I was like, oh, well what if we do some sort of like zone two training study?
We our lab study mitochondria, so it was a perfect fit. And that's when my supervisor, Dr. Brenda Gerd. I'm gonna have to quote him in my dissertation for [00:07:00] saying the most common phrase from him during my first couple years in his lab was, is that true?
Cause I would bring these things that I would hear on social media and he'd be like, is that true?
And then I'd be like,
Kristi Storoschuk : oh,
Both: well, I don't know. I heard it from really smart person. Like, I was just appealing to authority at that time. Yeah. Yeah. And, so zone two is one of those topics of, that doesn't make sense, that doesn't line up with what we know about physiology and mitochondrial adaptations and how we adapt to stress, the stress of exercise, because zone two isn't very stressful as, as far as metabolic stress goes.
Kristi Storoschuk : Yep.
Both: And so that's what kind of got me. Also just losing trust in what I hear online. Ironically, because this is a podcast, you mean some of the gurus
Dr Mike T Nelson: online may not be correct. Oh my gosh.
Both: Yeah. No it's, I don't know. I have mixed feelings about science, communication and social media because it's such a, I feel like it's a losing battle.
Podcasts at least [00:08:00] allows us to discuss the nuances. So anyways, my motivation was really just like, oh, him questioning me and me being like, wait, what? I don't know what I know now. I don't know what I believe. And so he was like, why don't you, why don't we find all the evidence we can that looks at any sort of zone two training study, pull out all the mitochondrial outcomes from all of these studies and see what the evidence shows.
It was a pretty basic like, aha, like this is. Obvious that something that's so commonly repeated online, like, how hasn't anyone done this? So I don't think we did anything special. We didn't do a study. We just basically looked for the evidence, which I feel like as someone who's sharing science online, so the people that were promoting zone two.
I think it was, should have been. It's responsible to find, have evidence to back up what you're saying on social media, especially with people with [00:09:00] huge platforms where what they say is actually changing the behaviors of the people that are consuming that content. Anyways, that's a, an aside. So basically for about six months a master's student in our lab, Andreas, Martin McDonald, and I, scoured the literature for anything that could even slightly equate to zone two. So we use the definition of zone two as a blood lactate level of two millimolars because that's how it's typically prescribed to the general public from the popular
Dr Mike T Nelson: voice online. So saying under that sort of cap, right?
Both: Yes. And so why, I guess just a quick little theory of why don't you, yeah. So. Blood lactate. Increases as exercise intensity increases, but it does so in a way that we hit like a little tick a little above our baselines. We always have a little bit of blood lactate in our blood. But as if we were to [00:10:00] do an incremental exercise test, as we increase exercise intensity, blood lactate will have a small bump above resting, and that's.
Typically around two millimolar, and that's considered our first lactate threshold as we increase exercise intensity above our lactate threshold. It'll start to increase a bit more exponentially until we hit this second lactate threshold and anything between our first and second lactate threshold.
If we were to do continuous exercise at a, like a fixed exercise intensity, we should reach a pretty steady state. But there's above our second lactate threshold if we increase duration out of fixed exercise intensity. Our blood lactate will increase exponentially and these two thresholds they also demarcate our exercise intensity domains.
So in exercise physiology, we don't talk about zones, we talk about intensity domains, and because that's what, there's actual physiological markers that we can use that [00:11:00] demarcate those domains. And there's different physiological responses in the moderate, which is the lowest, the heavy, which is in the middle, and the severe intensity domain, which is.
Our, where we would reach our VO two max. And so that's, so zone two falls right below our first lactate threshold, and that means our blood lactate's really low. So again, under two millimole. The way it's discussed online or prescribed is around 1.7. Millimolars. So, but no one's doing blood lactate testing.
But it's almost nobody. So we try to equate it to. Different things like percentage of heart rate max doing a talk test. So if you're able to sit in steady state exercise and still maintain a conversation, you should be breathing a bit heavier than you would just at rest. But you should be able to maintain a comfortable conversation that's typically [00:12:00] associated with our lactate threshold or our zone two.
There's RPE as well. So there's various different. I guess markers that try to anchor that two millimolar to something else. But it's not the, none of these things are going to accurately get you into zone two if that's what you're relying on. Blood lactate is essentially, or if you're, I guess wearing a metabolic attached to a metabolic cart and able to look at your VO O2 kinetics.
But otherwise blood lactate is the most accurate way to find these thresholds. So we looked for anything, any study that fell in what we defined as zone two. So anything two milli or lower, and pulled out any outcome that was related to mitochondrial adaptations or fat oxidative capacity because these are the, typically the the things that people promote zone two for.
And I'll just take a break and let you jump in if you have any questions.
Dr Mike T Nelson: Yeah. No, that's good. [00:13:00] Yeah, I think it's interesting that I am, I don't know if I'm guilty of this too, but it's the physiologic differences versus the zone, like zone 1, 2, 3, 4, 5. I found over time, I tend to speak more in zones now because.
It is just easier to try to convey an intensity versus exactly what you said is a hundred percent correct, but most people have no idea what lactate is. They have no idea what, okay, so now you're talking, well, well what is lactate? I don't know how this defines intensity. So you have to go through and explain how lactate is made, what it's doing, and it's easier just to say just do some zone three or just make it really hard.
But. Most people unfortunately then are probably not zoned correctly. Where did they get that from? How did they get it? And most people then are even using two 20 minus your age to find their max heart rate, which as I think the standard deviation on like what plus or minus [00:14:00] 17 or 19 or something astronomical was never really designed for that per se.
So I think it gets complicated really. Fast to try to define even just the intensity that we're talking about. And my question related to that is I've gravitated for zone two of using the talk test where, if you're talking to someone on the phone, they should be able to tell you're exercising, but you should be able to get out like complete sentences and have multiple sentences back to back.
Would you agree that is a. Without any technology at all. Do you think that is a useful way to define where the limit of a high end of zone two would be?
Both: Yeah. I think there was a study that we cited and it, yeah, there was a couple
Dr Mike T Nelson: studies on it actually. Yeah. That
Both: It was a kind of a reliable way in, I think it was just recreationally training.
Yeah. Or recreational active and individuals. I will say though, that I've done [00:15:00] now probably. Nearly 200 lactate thresholds in my, in the lab. And the very unfit individuals reach four millimolar or five plus and they're still like not even like heavy breathing. Yeah. They
Dr Mike T Nelson: look at a bike and their lactate spikes to like four and a half.
Both: Yeah. So ' cause they reached their lactate, they're basically at their lactate threshold at rest. Yeah. Just walking. So. I don't know how, I think it depends. It depends is my answer of whether that's accurate or not. 'cause it could be accurate for someone who's fit, but maybe the less fit you are, the least less accurate it gets.
So yeah, I dunno how accurate the talk test is or what population you'd be speaking to.
Dr Mike T Nelson: Yeah, my thought is if it's for a recreational lifter, aerobic person who's, like an intermediate, they exercise, two to five [00:16:00] times per week, they're not really that metabolically destroyed, but their cardiac system may not be the most developed either.
That's what I, my bias is, I think the talk test is pretty good for that. I haven't found anything else that's better. A hundred percent agree. It's not. The best. And as you become into populations that are more metabolically inflexible or very high stress, crap. Some of those people, I've done lactates on 'em and they're sitting at three millimoles just sitting in a chair looking at me.
I'm like, woo. Like you got some issues there, Bob, right?
Both: No, a hundred percent. But I guess I'll also get to. Like it doesn't matter.
Dr Mike T Nelson: Yeah. And why would you say it doesn't matter?
Both: From my perspective I think after writing this review that general public, I'm jumping to conclusions, but
Kristi Storoschuk : Yeah.
Yeah.
Both: We want to be working out [00:17:00] above zone two all the time, so. So knowing your zone two is irrelevant because you should just be pushing as hard as you can for what you're able to recover from. And if that's 40 minutes in zone three or 10 minutes in zone five doing intervals or something, then I think that the talk test becomes or fi finding your zone two becomes irrelevant because I just want, I would I believe that all the evidence posed.
Supports the use of zone two, zone three plus volume as promoting all the adaptations that we want for promoting better health.
Dr Mike T Nelson: Yeah. So your argument is, eh, it's a mute point because if you're a general population, you're just doing a ton of zone two, you're probably not gonna see a huge benefit from it anyway.
So trying to argue about what is the actual delineation of zone two is kinda missing the forest for the trees type thing.
Both: Right, right. I think it's foc focusing on [00:18:00] something that might not matter. Like there we do have evidence that low intensity exercise in very un metabolically unhealthy individuals does improve health outcomes and for to max and what everything, but that still doesn't mean that going above that isn't better, which our review pretty much supports the use of.
Of, yes, we've found some evidence that zone two can promote some mitochondrial signaling or activate some mitochondrial signaling pathways. But going above zone two almost always, if not produces the same but better outcomes than anything at our lactate threshold. So. So promoting zone two over higher intensities to the general public when most people just don't even exercise enough.
It could be it's discouraging people from doing higher intensities when they could be getting more bang for their buck or more metabolic health and [00:19:00] exercise adaptations from, and I think that's where, like this, I don't know it, it does, I get like emotional about it because I'm like, it's. It's preventing people from getting better health outcomes.
And I, that's, I want people to be healthy, so I want to make sure that things that are being shared online are evidence-based because people follow it. So I think that's, that this has become important to me to share just because I know that those zone two messaging is changing how people are exercising.
Dr Mike T Nelson: Yeah. And I think the key points there are that. And we'll talk about other populations coming up, but this would be for general population and of course it all comes down to compared to what, so you had a group doing three hours of zone two who are, just not very metabolically healthy.
Of course, they're gonna see some benefit from that. The question then is, okay, if you had the three hours to dedicate to old school [00:20:00] aerobic training, could you pick something better than zone two for any portion of that time? And I think the answer is, oh yeah, you could pick almost anything that is gonna be superior to that.
And I think telling general population that, yes, you need to increase your aerobic health is a good message. Your VO two max should probably be higher. Agree with all that. But then consequently telling them, oh, you need to do two to three hours of what they already hate doing. And then they're gonna do it for maybe six, eight weeks.
If they really get motivated, they hire a coach. And then what I've seen is, and I get a fair amount of emails on this, you probably get 'em too. Oh, I, I did like eight weeks of like zone two and I didn't really get any better. I redid my VO two max, however I did it. And I feel like I wasted all this time when I could've done something better.
And so now they don't trust the coach or the person they got the information from. They feel like they put in all this effort and they [00:21:00] didn't see a result from it. And unfortunately what I see then is they're just like, ah, screw it. I'm gonna go back to doing what I was doing before. This is stupid.
Exercise is dumb.
Both: Yeah personally, I've never gotten these types of emails and I don't think zone two is. Promoted to increase VO two max in the first place. It is just, it's al, it's like there's divergent adaptations. Like we do 80% of our training in zone two for our mitochondria and our fats.
Yep. Native capacity. And then we do that 20% at high intensity zone five for improving VO two max. And that distribution, that 80 20 comes from elite athletes who, yep. Are exercising 20 to 40 hours a week, where 80% or that 20% that's at high intensity is still above what that would look like in just someone who's exercising maybe three to four times a week for 30 to 60 minutes each bout.
So there, so to. We're [00:22:00] correlating that 20% or that eight that elite athletes have pristine mitochondria, great metabolic health, very high performance, and we're saying that it's the result of that 80% spent in zone two when all the evidence would su suggest that all of that, those adaptations come from that 20% spent at high intensities.
It's just because that number is so much smaller. It's like this cognitive dissonance where we. Associate the large number with the results versus considering that many of that, those adaptations are probably promoted by that smaller volume spent at high intensities. And then when it, when that gets.
Portrayed to the general public, like, oh, we should be doing 80 20. Well, someone who's working out four hours a week, 80 20, they're doing no high intensity and they're doing tons of low intensity when they're missing out on the benefits of high intensity then. And so the 80 20 distribution trying to place that in the general public.
And [00:23:00] to non-athletes and like I, I'm a recreational exerciser. Like I don't put myself in the, I exercise most days of the week, but I wouldn't ever consider myself an athlete. So I, like I would placing that 80 20 rule in someone like me who exercises 30 minutes a day, that is completely misplaced because.
That large training volume is why they do 80 20. So the percentage distribution makes no sense when it, when the training volume is so much smaller.
Dr Mike T Nelson: Yeah. And I've often said that, couch potato physiology to elite athlete physiology are just, they might as well be in a different universe. Like a lot of the same principles still apply.
They still work the same way, but. The outcomes and the recommendations you get, don't transfer between the two. And I feel like there was, and I think it was Casandra Milan who did a lot of that original work and that was an elite level [00:24:00] cyclist. And if you ever looked at the power output of an elite level cyclist in zone five, it's absolutely bonkers.
Like they're legit working for zone two. It's probably higher than someone who's not really trained in zone five. A hundred percent. Yeah. They're not even, they don't even overlap in almost any part of the spectrum. So trying to transfer, something from elite cyclists down to general population, I think is not the best idea.
And then I've also wondered, even with those studies and elite level cyclists, have you've ever worked with any elite level cyclists? They're all crazy nut bags. Like if you tell 'em to do zone two, they'll probably follow your prescription. But if you tell 'em like, Hey, just go do an easy ride, or just don't ride today.
It's zone three, zone four, oh, I did a bunch of hill climb. Like it's definitely not easy work per se. So I've often wondered how much of the benefit [00:25:00] even in that population. Is it zone two or was it the fact that you're just not dropping the hammer like every single day and accumulating this massive amount of fatigue also?
Both: Yeah. And that's a really good point because there might be some benefit of zone two for elite athletes.
Kristi Storoschuk : Sure.
Both: That we just don't know yet because the studies have not been done. Because their power output in zone two is. So much higher than what even a recreational athlete zone two would be. And just that amount of power output, like the amount of muscle recruitment, the amount of blood flow, the amount of work your body has to do to be able to meet that energy demand.
Even in zone two, even though blood lactate is low there might be some adaptations in someone who zone two is just so high. Because of just the absolute power output. Even if the relative output's the same, that absolute value might be pushing adaptations in elite athletes. But that's just, that's also just a theory like that's not [00:26:00] been tested yet.
But the point being that. Elite athletes might be benefiting from zone two, but those benefits are probably not going to be seen in someone with a lactate threshold of 80 watts. So
Dr Mike T Nelson: how did we do you know how we got here? Like how, and I've been trying to trace this back and I don't have a good answer of.
How do we get to the messaging that people should start with zone two? Because you can, you've obviously looked at all the literature on this too, and Canadian guys, like, Martin Gal and a bunch of other people have been doing high intensity interval training and stuff on general population, not even just elite level athletes for freaking decades.
It's not like the data wasn't there and we're like, oh wow, we have all this brand new data and so we're gonna change our mind on it. To me, at least when I look at it, and I know you've done a better research review of this than I have, most of the data was there. We [00:27:00] just seemed to ignore it, I don't know.
Both: Yeah. Well, I think we were just extrapolating from these observational correlative studies in elite athletes and being like, okay, well they do it so it must work. Instead of finding actual experimental prospective studies that. Put an inter like study an intervention of zone two. We're basically just extrapolating from these observations in athletes and assuming that because they do it, it works.
So don't even question it. But where it, like, the history of all of this and like why where 80 20 came from is something that I'm really interested in digging more into. And it looks like it started in like the 1950s. Name of Arthur Liddiard. I'm just started reading about this now because I wanna know the history of like, where did this come from?
Where did the pyramid come from? Why do we have this perception of a base pyramid? And that's, that base is built with zone two, and then everything above is where we get to. We [00:28:00] basically earn the right to do higher intensities as we work our way up the pyramid. But first you need to build that base, that aerobic base.
And the idea of that also just doesn't follow what we know about physiology because you can do high intensity work and build your aerobic base. Our aerobic adaptations are built through metabolic stress, through sheer stress, through like doing hard efforts. That's how we elicit those adaptations.
That make exercise easier the next time we do it because we became fitter. Those we adapt so that we're more well prepared for that in that bout next time. So we have to stress the system. And working below lactate threshold is the power output, the intensity that is supposed to elicit the least amount of stress above what we would just resting and sitting.
Because we don't accumulate much blood lactate. We don't. We don't break down much glycogen, we don't activate our [00:29:00] sympathetic nervous system. We don't like. Everything is very, we can exercise with very, with accumulating very little stress. And that's maybe why athletes do it because they, well, it's definitely why athletes do it because they want to increase their training volume without accumulating stress for which they would have to recover from.
And when we do hard bouts, we do have to. Allow ourselves time to recover. So whether zone two is maybe improving recovery not being, but it's positioned as it's actually causing adaptations, whereas,
Kristi Storoschuk : right.
Both: It might just be supporting recovery or just psychologically allowing athletes to exercise without.
Incurring any stress. But what, whether it's promoting mitochondrial and aerobic adaptations, that's where I don't, there's not strong evidence to support that. But yeah, so when it comes to the base though, like Yeah, this idea, like the way endurance training coaches conceptualize is like we do a lot of this base [00:30:00] training, like we work at it low intensities, that's our large volume.
We build that base of the pyramid and then that allows us to basically tolerate the high intensities. Whereas I think that the PY image should be flipped and that you start with high intensity to build the aerobic base. And once you've. You work your way up to the base in that you max out how much high intensity you can do that you can recover from.
So like your recoverable volume, and that'll probably change from person to person based on your lifestyle, like your nutrition, how well you sleep, et cetera, your age. But however much zone three plus volume that you can tolerate and recover well from. Once you max that out, you essentially deserve the right to do zone two.
And, but the way it's promoted right now is that zone two be prioritized before you do high intensity. So I think we have it backwards, to be honest. [00:31:00]
Dr Mike T Nelson: Yeah, I would agree. Like if from a programming standpoint, all things being equal, if I'm not worried about how much higher intensity work or lifting or technique or anything else, like, there's a bunch of other factors that go into it, but.
If you came to me and said, okay, this person is recreationally active. Your goal is to get the highest aerobic adaptations from them possible, we'll do that by measuring VO two max. Yeah. The first thing I would program would be some intervals at VO two max. Now, again, in some of my programs, I may not have people.
Start with that because I may be worried about their technique or interfering with, their recoverability with some of their lifting or prioritizing other things. But if they said, okay, you don't have any other priorities, and we can guarantee their technique is gonna be solid, they're not gonna have any mechanical issues doing it.
You don't have any other stressors to worry about then? Yeah, I'm definitely gonna go, a hundred percent of EO two max or probably two to [00:32:00] six minute intervals and then just try to see how far I can push that over several weeks.
Both: Yeah, and like it doesn't even have to be like, so a lot of the literature, like especially when it comes to mitochondrial, well, particularly when it comes to mitochondrial adaptations.
Which is, was the focus of this review suggest the volume is a key factor that is associated with positively with mitochondrial content. And people take that to think that, okay, well we have to accumulate these large volumes and by, we can accumulate large volumes by doing zone two, but. Missing from this conversation is that the studies that are used within this correlation are often above zone two.
So even these moderate intensity continuous training studies are often prescribed at like 65% of VO two max, which for a recreational individual is almost certainly above zone two. So their lactate is likely [00:33:00] above two millimolars. In a trained person, it could very well, 65% could very well be. Below their lactate threshold, but for most just recreational people.
So when it comes to general public the associations between volume and mitochondrial content is not evidence to support the use of zone two. And I think that's what gets lost in the conversation. As well as that all continuous exercise is zone two. It's like we're.
Kristi Storoschuk : Zone two or we're doing,
oh no, what was that? I just got a recording in progress.
Dr Mike T Nelson: Oh, I did?
Kristi Storoschuk : That would be really ironic if you were like, oh, I always record from the beginning so that I don't forget. And then it
Dr Mike T Nelson: Oh.
Wasn't it recording the whole time?
Kristi Storoschuk : I thought so. 'cause when I jumped on the call it said Recording in progress.
Dr Mike T Nelson: Well, we'll just keep going and hopefully it's okay. 'cause I always set 'em to auto record each time I go in. So, because you got a little notice that it was recording as you went in, right?
Kristi Storoschuk : Yeah.
Dr Mike T Nelson: Okay. Well I think we should be [00:34:00] okay, so, all right we'll keep going and cross our fingers.
Kristi Storoschuk : Okay. I'll start from my point of that. What gets lost in the conversation is that modern intensity, continuous training is often thought like. Zone two is often just thought of just continuous training. So the arguments get it's zone two or high intensity intervals but not all continuous exercises.
Zone two, you can do long durations an hour in zone three, and I think you would get better adaptations doing that than you would be zone two. It's just that people often associate all continuous exercise with zone two. And then when we look at studies like big meta-analyses that show that Modern 10 gives you the same adaptations, whether it's via two max or mitochondrial content as.
High intensity intervals. So if we're saying mict is the exact same as HIIT over the long-term training studies, people use that as evidence that, oh, look it. Zone two is you can do large volumes of [00:35:00] this low intensity stuff without the pain of doing high intensity intervals, and you're gonna end up in the same results.
So you just do a lot of zone two, but. The problem is that those mixed studies are above zone two. And so it's not it, we're mixing up the idea of continuous exercise, steady state exercise as that zone two when all like the evidence for mixed is likely like zone three plus.
Dr Mike T Nelson: Yeah. And MIT you're saying moderate intensity training, right?
Kristi Storoschuk : Yes. Sorry, moderate intensity, continuous training.
Dr Mike T Nelson: That's, yeah. Yeah. No I agree with that. And again, it all goes back to. What population are you talking about? How trained are you? Most people, yeah. Maybe a true zone three. They could do for quite a while, but if you're not as well trained, you probably not as long.
And again, the benefit you have of being less, let's say aerobically trained is you. You don't need as big of a stimulus to see a positive effect. It's just like weight training. If you've never weight [00:36:00] trained before, you could probably curl frigging soup cans and get stronger for a few weeks. Like you don't need a huge intensity because anything you're doing is gonna be beneficial.
But there is these kind of threshold effects where if you wanna see more of a benefit or you want to try to see the. Maximal adaptation for what you're doing, then yeah, you have to do something that's intense. But by definition, if you're not as well trained, that absolute numbers, like we talked about, are gonna be quite a bit lower compared to people who are trained.
Kristi Storoschuk : Yeah. And I think of like mitochondrial and aerobic adaptations, like resistance training. It's like progressive overload. Yeah. Like you always want to be stressing the systems that we adapt and get better. Whereas zone two kind of contradicts that theory.
Dr Mike T Nelson: Yeah. And back to the base and where a zone two base comes from.
I don't know what your thoughts are on this, but my bias, and I'd have to go back and look at all the literature again, but I think it came from kind of Ken Cooper's work like many decades ago. [00:37:00] And I think it was based on running. And I think where it came from is the fact that if you took a lot of people who are not very good at running.
And you have 'em do higher intensity of work running. You just blow up a whole bunch of people mechanically, not necessarily aerobically. And I think because of the extrapolation of a lot of the early exercise, fizz work was on a treadmill. Yes, there's been a lot of bike work that's been done very early on, but it looks like the bias was definitely more.
Look at all the old school metabolic heart studies, VO two max, like most of them were treadmill based studies. I've often wondered if that recommendation was based on running and was more from a mechanical limitation of we just need your system to get used to this impact loading of, six to 10 times body weight and we have to start at a lower intensity because of that.
Not necessarily because of the aerobic stuff, where I think if you did it on a rower or a [00:38:00] bike or something like that, I where you don't have that impact, I think you could do things differently. I don't know what your thoughts are on that.
Kristi Storoschuk : No I agree with that. Like. If that is the case for doing larger volumes at low intensity, sure.
Like there might be benefit, particularly maybe with running that doing like long, slow runs is benefiting the system. But I still think that. The messaging is like, oh, you have to do large volumes for your mitochondria and your fat capacity, which that is not supported by evidence. And so it's not to say like, oh, don't do zone two.
Maybe there is some sort of benefit from it, but I think we just are giving it a rationale that isn't evidence-based and just like perpetuating that message. And so sure, like there might be. Some sort of biomechanical benefit, especially like you said, with running. But that's not something that I've necess that I've addressed personally and that's not what our review [00:39:00] addresses.
So I do think that people could make a lot of good reasons why we should maybe be doing low intensity zone two training. But the messaging does seem to be promoting. The use of it for mitochondrial and fat, oxidative and metabolic flexibility specifically and for health reasons. So I don't disagree with you, that could be a very logical rationale for promoting those like biomechanical adaptations that support your ability to even sprint.
Dr Mike T Nelson: Yeah, and I agree with you. Like I think there was a. Because of that if that theory is correct, that we over extrapolated that and said, oh, well look at all this old stuff on this, aerobic base building and this group of runners did it, so therefore this is what we need to do for maximum mitochondrial and aerobic adaptations.
And again, you did see some of that in, some of those early studies too. But yeah, I don't, it, it just seems like [00:40:00] a lot of stuff just never. Gets questioned as to why and looked at from a different perspective. It's just carried forward. And the other part, which is my pet peeve, is nobody actually reads any research.
Like nobody. Not nobody, but very few people read the actual. Research of what that was done. And for years I had this old study by Hixson who just beat the ever living crap out of these people and saw absolutely massive aerobic adaptations. Like I think the average in the group went up by 17 milliliters per kg per minute over.
It was like a 10 or 12 week study. Just insane. And I purposely. Did not talk about it in public for like two years, because I was super curious if anyone would find it with all these people talking about VO two max and aerobic training and all this stuff they're doing. Nobody did. And it was an old study and [00:41:00] I don't think you can replicate it now and have, you'd have so much dropout and everything else, but just because it's an older study doesn't mean that it's bad.
And some of the early work was very. Interesting. So it just seems like a lot of it is just parroting, oh, this sounds good. And if the has a logical sounding explanation or a good mechanism to it. Like if you can put three mechanisms to something, oh my God, everyone will believe you now.
But again, like you said, is this true? Like we have to go and look at what did the actual outcome studies say? And again, in what population was it done to have a better idea of what could be a better application?
Kristi Storoschuk : Yeah, I'm gonna parrot your parroting sentence because that is, that, I think that is what, why zone two got so popular is just like the parroting of something someone heard from an authority figure and then just got repeated so many times until it became truth.
[00:42:00] And that's what, like, I hope that our paper, allows people to question and think and being an example of questioning something that is so strongly held. It's funny, the, like psychology to witness like the reactions to this paper in that a lot of people. We'll be like, we'll, praise us a group for writing this paper.
And then still end with, oh, but we still have to be doing zone two. It's like this, the more
Dr Mike T Nelson: research is needed.
Kristi Storoschuk : Yeah. And like there more research, but you could say that about everything. Yeah. Like there hasn't been the zone two studies that we would want that warrant these types of claims. So those studies haven't been done.
But like, it's just really. Interesting to see the like reaction to this paper of people who are zone two proponents who are like being like, oh, I'm so happy you wrote this paper. It's so great, [00:43:00] blah, blah, blah, blah. But like, athletes are doing it, so like it must be doing something that we just don't know about yet.
And it's yeah, I don't know. I don't know what my point is other than it's really interesting to witness.
Dr Mike T Nelson: Yeah, and I'm guilty of this too. You can find some older stuff from me where I'm like, yeah, I do zone two and then do some high intensity stuff. And, but as I started doing it and then especially when I went back and started reading more of the literature, I was like, oh man.
So I did zone two with this person and we did some base building. But the V two max didn't go up, so maybe we needed a bigger foundation in order to do it. But then I'm like, well, maybe we can just add more of the higher intensity stuff in first so we don't have to burn eight weeks to try to get their base up.
And then when you start testing stuff like I'm a weirdo who has full moxie set up a freaking metabolic card in their garage, in their home, like you, you realize, oh, I probably don't need to do all of this low volume [00:44:00] work. Again, I think there is some benefit to it from a movement and a recovery standpoint.
And if you look at a lot of, even the old Russian literature, it basically would say anything to move blood flow around is probably gonna help your recovery, right. So I think you could make an argument for that as a recovery modality. Sure. Yeah. I think that's cool. Like I would probably agree with that.
But to say that this is the foundational thing you need to do, eh, I've it changed my mind. Now we're, now if you said, okay, you have a general population, what would you recommend them to do? I'd be like, yeah, do some VO two max intervals at least once a week, and then probably do a lot of zone three stuff if you can get away doing zone four.
Great. My question then is, have you noticed that some people just seem to handle. Higher intensity better than others. Like I can think of a couple people I've coached with in the past where their sleep was pretty good. Their HRV scores are [00:45:00] good. Like their lifestyle's pretty good. The people we're at probably relative similar VO two max, and some people like I could just absolutely obliterate them with like literally like true high intensity stuff.
They somehow would recover. I would say those people are definitely not the norm by any means. Where the other athlete who looks almost the same on paper, man, like one session a week was about all they could tolerate. I would say that's more the norm. Have you seen something that's similar to that or do you have any thoughts as to what.
Might be going on 'cause I'm at a complete loss.
Kristi Storoschuk : I do know that there's over-training studies where they tried to overtrain the participants and they couldn't, like, they retested them halfway through. And their performance just kept getting better and better when they were trying to get them into like over training.
And I think those studies, correct me if I'm wrong, were. Interval training only. And they were not necessarily weight training or doing anything [00:46:00] else, correct? Yeah, they were cycling interval training studies. Yeah. And they were doing like two aday and Oh yeah. They
Dr Mike T Nelson: were brutalizing them for, was it six or eight weeks?
I can't remember the duration.
Kristi Storoschuk : Yeah,
Dr Mike T Nelson: yeah.
Kristi Storoschuk : And they couldn't, like, they were trying to induce overtraining and they couldn't. So I don't know. I just think that. I think we can handle a bit more zone three plus volume than we think we can. We've run some pretty intense training studies in our lab.
So this is just simply my observations, not even my study. It's just me just like coming into the lab and seeing the participants. And there's definitely people who come in. It was three days a week. And it was five times, four minute intervals at 85% peak power output. And so they were really hard intervals, like four minute intervals are actually so hard.
That was horrible. So three times a week in cyclists, these were trained cyclists and there were people who could handle it and would come in with a smile on their face. And there were people who. Absolutely hated and probably regretted signing up for the study. So I [00:47:00] do think that there's just an individual response, 'cause relatively they're all working out at the same intensity, doing the same protocol.
Yeah. So I don't know. I would lean on the studies where they tried to overtrain doing two a days for, I think it was up to four weeks, and, yeah, they didn't induce any overtraining. So not to say you can't overtrain, like for it's for sure if you're doing intervals every single day for week on week, months, on months.
Like you are gonna, you just, you're gonna know though when you're tired, like, and you're gonna get to that day and you're gonna go, you know what? I don't think I can handle another interval session today. I'm gonna do 30 minutes in zone three. Like, it's, you just, you're allowed to listen to your body and know when to change things up.
But I just don't know if. That's like a, I just still don't think like, oh, we need to structure and zone two training into our routines. But that's just my opinion. Like, I don't coach people. I don't, I'm coming from literally like the scientific literature is what it says based on experimental evidence.
I'm not necessarily coming from the perspective of [00:48:00] working with individuals. And I will admit that's probably. That my perspective is gonna be different from someone who works with real people. Sure. And that is okay. And maybe zone two has a place when it comes to the psychology, the recovery, et cetera, et cetera.
But what I'm addressing again, and I keep reiterating just 'cause I wanna make sure that like I'm not getting cornering myself into anywhere, is that we literally just looked at does zone two. Zone two, like in inherently better than higher intensities for promoting mitochondrial adaptations and fat oxidative capacity.
And that is where I put my, like the line in the sand. Anything else is me just exploratory within the literature and and theorizing.
Dr Mike T Nelson: Yeah, no, that's great. And then again, I point back to the SSON study where I can't, I'm blanking on what it is now, but I had it in the Flexible Meathead Cardio course.
I wanna say it was six days a week, I think on the two run days. They're told just go run as [00:49:00] fast as you can for like 40 minutes. I think the three or four other ones were just some freaking hideous interval training. I wanna say it was 12 weeks. I think they measured 'em at least once or twice during the study.
And the running the joke, which falsely is the rumor is that, back in that lab there was a kind of a comparison that no, most of the people doing the study were working in the lab or friends of people in the lab. And the running joke was that no one wanted to be the pussy who dropped out of the study.
So the, what I heard, and this is all just conjecture, is that there was a lot of. Competition with one another to make sure that the, they didn't wanna be known as a person who didn't finish the study. Right. But the rumor was that all of them hated it. It was the worst training they ever did in their life.
They probably never did that again. But from a result standpoint was highly effective. Again, they were not weight training, they were not doing anything else, per se. So I [00:50:00] do think that there is something where. How you, you feel and your results don't always match up, which isn't to say don't listen to your body or anything like that.
The one thing I use in the real world is I would say, look at your output. And if your output is demonstratively much lower and your RP is still high, okay, then maybe you don't do as many intervals that day. But it's also shocking how often, and this happens with weight training happens. I'm sure it's happened to you.
You are like, oh man, I don't wanna go to the gym today. I just feel tired. I feel off. Yeah. My metrics are so, so when you get there, you do your warmup, you get into your first working set. By the time you get into what you're actually doing, you're like, oh, I feel okay. And the session was pretty good. Maybe not the best session ever, but probably not the worst session ever.
So I always tell clients that don't. Equate how you feel per se, until you get to the point of doing the thing and you're warmed up and into it and then look at your output. If your output is [00:51:00] demonstratively like way off, then yeah, it might not be there unless we're purposely trying to overreach you for a period of time, then just leave.
But it is interesting how more often than not, and again there's a limit to this, you can usually do more than what you think predicting going into the session.
Kristi Storoschuk : Yeah. Fair. And I think like that would be shown within the literature because there's tons of hit studies where they do it. My hit study was five days.
Mind you, it was just five days, but it was Monday to Friday. It was every single day they came in consecutively and they could do their intervals at a hundred percent or max. So yeah, like it's doable. Whether, and that's why I say like, I think when it comes to trying to figure out like, oh, what do I do?
It's figuring out your, like. Maximal volume zone three plus. That's your maximal recoverable volume. Sorry. So whatever that looks like for an individual, it's whatever you can do. Hard [00:52:00] efforts that you can recover from. It's when you start getting into those like, oh, I'm now sick and now I have disturbed sleep and now my HRV is tanking, or et cetera, et cetera.
Any marker of over training, that's when you could consider like pulling back or adding in something like zone two.
Dr Mike T Nelson: Gotcha. What are your thoughts about frequency? So, one thing, and this is again, my bias based on the literature and just. Practice of doing this stuff with people for like two decades is I would make a harder argument for more frequency with aerobic training than I would with anaerobic or lifting.
What I've seen is if schedule, not decide it, if I can get someone to do some type of aerobic training, six outta seven days of the week, it seems like they get better progress. And again, if you look at some of the. Mechanistic studies, and again, this is probably an over extrapolation of how [00:53:00] long certain things, stayed turned on and turned off.
It's a few hours. It's not like weight training where you could have muscle protein synthesis still running 48, potentially 72 hours later. So my argument is that you do the thing to get the stimulus, you see the outcome. That sort of returns back to baseline again, not all the time. There's some high intensity stuff that stays a little longer.
And then you basically give the stimulus again because now you're back at baseline. Now you can elevate it again. And you just do that with more of a frequency based approach.
Kristi Storoschuk : Yeah. So wait, what are you specifically asking? Like what's the ideal frequency?
Dr Mike T Nelson: Well, I'm just thinking, would you agree that if all things being equal, would you push frequency of aerobic training as one of the.
Modalities that you would play with, like going higher frequency versus lower frequency?
Kristi Storoschuk : I don't know what the like minimum return is. Like what if
Dr Mike T Nelson: you do it
Kristi Storoschuk : once a week, do you, like, what's the difference [00:54:00] between that versus twice a week versus three times a week? I have no idea, but I would say,
Dr Mike T Nelson: yeah, I can't, probably wouldn't go longer
Kristi Storoschuk : than you probably wouldn't go, I can't find a dose response
Dr Mike T Nelson: study.
Kristi Storoschuk : Yeah I'm not sure dose response, but I wouldn't, I would think that you wouldn't wanna, we wait like a week between, like only doing once a week sounds like not enough.
Dr Mike T Nelson: Yeah. Yeah. But
Kristi Storoschuk : anything over a week probably, that's probably where it, like the minimum dose is. 'cause if you're only doing like a hit session twice a month, like every other week,
Dr Mike T Nelson: yeah.
Yeah. That doesn't sound
Kristi Storoschuk : like it's gonna promote much adaptation. So, so, yeah I actually have no idea frequency.
Dr Mike T Nelson: Yeah. Because I've done a, what I call a six minute progressive. So they'll start like on a rower or salt bike and not necessarily do any warmup. And then the goal is after six minutes, you should be at a relatively high RPE of a eight or nine, but only for the last third, and I've [00:55:00] done this quite a bit with a fair amount of people. These, again, are recreational lifters. These are not necessarily aerobic athletes, but they're not necessarily untrained either. And it just seems like six days a week of doing that and you get a fair amount of zone three work. You get some zone four, maybe not quite touch zone five near the end.
But it's also only six minutes. So it's not a huge duration of time. And most people just doing that in the morning separate from their lifting. Or you can do it before lifting. In addition to doing some intervals that week. I don't know. That's kinda what I've found as just the sweet spot of it seems to be most people can get a fair amount of aerobic adaptation from that without having to do a high amount of work.
But again, that's all completely anecdotal and the only reason I found that is I just played with everything for like two years just in a, just because if you go. Too hard for too long. I found that it definitely limited their lifting [00:56:00] sessions later in the day, which I didn't want to do. And then if you went all the way down, and I've done some two stuff for, 2, 3, 4 hours a week, in some people it just seemed like that was not enough intensity to see marketable change.
And then they would still do some aerobic stuff and maybe Tuesday, Thursday on that too. But it just seemed like that. Frequency of exposure to get just that enough intensity was beneficial. But again, I can't find any literature that backs that up directly. I can find a lot of stuff that's indirectly supporting that.
But just curious on your opinion of that.
Kristi Storoschuk : There's sprint digital training studies Yes. That. Are the tiny, it's like up to down to ten second intervals that are activating
Dr Mike T Nelson: yeah, like
Kristi Storoschuk : our adaptation pathway. So, but I
Dr Mike T Nelson: think those kind of, correct me if I'm wrong, but from an outcome standpoint, I think those kind of maxed out within a couple of weeks though, didn't they?
Or not?
Kristi Storoschuk : I have no idea. But I would also, just based on that idea, that spend interval training studies [00:57:00] aren't very long in duration. Right. So who knows when you do them for. A long time. Yeah, that's a problem too. Like all of our hit studies are like four to six weeks. Like there's a few 12 weeks.
Yeah. I was just
Dr Mike T Nelson: gonna say like, I can't think of a study that's that high intensity that's even longer than that.
Kristi Storoschuk : Yeah. So I don't know when like things would pla, like our adaptations would plateau per se, but if you're using, I don't know, sprint in a real training, like a Tabata or something, that's four minutes of your day.
Yeah. And if that's what's maintaining any sort of adaptation from, or inducing any add further adaptation from your actual structured interval, like longer interval training then why not? It's like, yeah, it sucks for, it's not that much work. And it's four minutes.
Dr Mike T Nelson: Yeah. Yeah. I'll say my little tyrant about the Tabata study, but my short version is most people.
What they say they're doing is Tabata is not even close. Right? Because as it's 170% of your vo. [00:58:00] O2 max is the intensity. So if you can keep that up, then yeah, by all means, like great do it. But then you invert your rest period for 20 seconds of work and 10 seconds of rest. I usually just find most people are not.
Trained enough to do that. But I think you can take the principle of doing high intensity work as long as you can keep the quality up. And I think you should definitely play with that, especially if you're really rate limited on time.
Kristi Storoschuk : Yeah. Yeah. Side story. I met Dr. Tabata.
Dr Mike T Nelson: You did?
Oh, cool.
Kristi Storoschuk : Last year at the conference. How was that? He's a very short, cute. Old man.
Dr Mike T Nelson: Did you get to ask him about the study?
Kristi Storoschuk : He did a presentation it was at a conference in Montreal.
Dr Mike T Nelson: Oh,
Kristi Storoschuk : cool. No, I didn't ask him any questions, but it's all, we're all pronouncing it wrong. It's tapa. Oh, is it? Oh, shit.
Okay. But I still like Tabata. It sounds better. He was just sharing all of like his [00:59:00] history of his research and everything, showing some photos and, yeah.
Dr Mike T Nelson: Oh, that's cool. I would make an argument that in terms of aerobic anaerobic training in the fitness world. Out of, if I were to rank all the studies in terms of popularity, I still think that is the most popular study that's ever been done.
Kristi Storoschuk : I don't even know what like exact study 'cause Oh wait, is he, 'cause he only did like two studies or something, right?
Dr Mike T Nelson: Yeah. I think he only did real one main study, which I might have the date wrong, but I wanna say it was 1996, I think.
Kristi Storoschuk : Yeah. And then be wrong on that. Just took off with the one study.
Dr Mike T Nelson: Yeah.
Kristi Storoschuk : That's crazy.
Dr Mike T Nelson: It's like the zone two things. It's good for him. We can take marketing. Yeah. Which is great
Kristi Storoschuk : marketing advice from Dr. Tabata.
Dr Mike T Nelson: Yeah. Which again is great, but it's just like on the high intensity side, I feel like that's the study that just gets parroted as oh, Tabata one arm, preacher curls.
It's like, what do you, did you even read the study? Like what are you doing? Like it just seems like that's the name. We're gonna stick on everything now. [01:00:00] Just like. Oh, zone two, but just do this interval. Oh, you don't wanna be on a bike. That's okay. Just do all this other, body weight stuff and whatever, and we'll call it zone two.
It just seems like these labels just get tossed on everything at some point. Yeah, totally. Tabatas just, so basically a timer at this point.
Yeah. Yeah. What are your thoughts about walking? I've heard. People say walking is cardio to walking. Should be your zone. Two to do doesn't even matter to I again, it seems crazy to me.
Kristi Storoschuk : I think walking is great. I
Dr Mike T Nelson: think
Kristi Storoschuk : your step count is really important in a day. Your non-physical activity or non-exercise, physical activity matters. Whether or not it's inducing adaptation, I don't think so, but I think it's just elevating your energy expenditure and like you said, getting blood flowing.
Like that's gotta be good for you. Reducing sedentary time we obviously know is super [01:01:00] important, but thinking that's. Necessary for some sort of adaptation. I would not say so unless you're severely unfit, then it could be ex walking, might be your zone three. We had a study done in at Queens where 75% of VO two max was brisk walking because these people were, whoa, just overweight, sedentary, metabolically impaired individuals, and they compared low intensity to high intensity and the high intensity.
Was brisk walking. So that just goes to show that like the population that we're considering is so important when it comes to like the actual exercise intervention. And that study also is really important for just showing that high intensity for volume matched high intensity, promoted greater health outcomes and adaptations than the lower intensity training group end.
That would suggest [01:02:00] like all this messaging of zone two for people with insulin resistance being like, oh, we have to get these insulin resistant people doing zone two to help their, get their mitochondria and their fat safe capacity. Get it, get that in place. Like when we look at actual intervention, exercise intervention studies.
S high intensity will be better for promoting those insulin sensitive adapta or like improving insulin sensitivity, improving glucose control improving VO two max, et cetera. Those, that's what we're after when we're talking about health and exercising for health. So yeah I don't think, I don't think sacrificing time spent at high intensity and in place for low intensity is not the right way to go about it.
Dr Mike T Nelson: Yeah, and I think in those studies like, high intensity interval or even weight training for. Glucose sensitizing effects, the effects stay around much, much longer than like just zone two stuff, right? You think of how far you push the system away from [01:03:00] homeostasis and how long it's gonna take to get back down.
Like you can. I even tell people just play with this yourself. Like do like an hour of zone two and then see how fast, again, this is recreationally active person, how fast your heart rate gets back down to almost resting. In my experience, it's really fast. Again, so that doesn't mean there's no effect, but that just means that you haven't really pushed the system that far away from its baseline.
And again, you can get too far carried away with that. And do you know, too much intensity, but it seems a little. Weird that we would expect tons of these massive benefits to come from, eh, we just pushed it off baseline a little bit.
Kristi Storoschuk : Yeah, no, it's so when you say it like that, like it does seem intuitive to think that, okay, intensity is what's driving these adaptations and these outcomes that we're seeking.
But this doesn't, again, I'm gonna come back to it like, it doesn't mean you have to do all these crazy intervals and kill yourself. It's literally just push yourself as hard as you can, and that might be. Zone three for that [01:04:00] day. Yeah. What your hard as you can, might be based on many different things and how you subjectively feel that day or objectively feel that day.
And I just think that the messaging should not be to deliberately structure in zone two if we're trying to improve our mitochondrial capacity, if we're trying to improve our fat native capacity. And if we're trying to improve our health.
Dr Mike T Nelson: Yeah. One of the things I have in the shameless plug for the me cardio course is that.
For lifters, I've had 'em do on the rower, like either 500 meter or a one K before their lifting session, maybe not before your leg day, and have it be at an RP of a seven or an eight, meaning that you should be back to baseline within three to five minutes and it should not drastically affect your lifting session after that.
So, but you're still getting a fair amount of intensity with that too. And again, again, this is purely anecdotal, but we've seen. Pretty good benefits from that too, [01:05:00] because now you're back to, again, the frequency thing where I, my bias is I think if you can do some intensity work or do something above zone two and do that more often, like if you look at the total accumulation of high quality work over the week, it's gonna be a little bit higher than trying to cram that all into, one day.
Kristi Storoschuk : Yeah, no I agree with that.
Dr Mike T Nelson: So, as we wrap up here, one of my last questions is. Does these changes in mitochondrial pick your mitochondrial favorite metric? Do they translate to actual performance changes? Because my assumption on this would be, of course they do, but then some of the literature looks like, all things in physiology, it doesn't appear to be like a direct transfer.
And you'll even hear other researchers say that mitochondria are overdesigned, meaning that we probably never get close to really maxing out our mitochondria. I think we even talked about this in our first [01:06:00] podcast that it's gonna be a right limit or a performance, but we all know that if you're, if you don't have any mitochondria and they suck, like it's gonna limit your performance.
So what are your kind of thoughts on that?
Kristi Storoschuk : I've never addressed this question specifically, but yes, you're right. That like we have more capacity. It just seems really to messy than what we Yeah. Like our mitochondrial capacity. Like we probably don't get to that mitochondrial capacity.
Dr Mike T Nelson: Right.
Kristi Storoschuk : Wait, but how did you lead into this question? 'cause I had an answer and then
Dr Mike T Nelson: I forgot. That's all right. To me, it. It's fuzzy because on one, so if you look at the ends of the spectrum, right, there's some that's showing, oh, whether it's
Kristi Storoschuk : tied to performance. Yeah.
Dr Mike T Nelson: Right. We see increases in mitochondrial change.
We don't necessarily always see increases in performance, but we know that if you have really very few mitochondria and they just suck, like they don't work well. That is definitely gonna limit your performance. But it, again, it's, it doesn't appear to be this direct one-to-one transfer. And again, rarely is anything in physiology [01:07:00] completely, linear where you put this thing in, this always comes back out.
So what are your thoughts about all of that?
Kristi Storoschuk : Yeah, I don't know. I don't know. Okay. If mitochondria, how it's associated with performance. I've never looked at that specifically. But mitochondria is obviously, it's a determinant mitochondria. Capacity is a determinant of our aerobic capacity of our lactate threshold, which is a determinant of performance, both of those.
Sure. So I would say that either directly or indirectly, our mitochondrial capacity, both respiratory capacity and content are associated obviously with performance, but whether there's like a, oh, I improved my mitochondrial. Con, I increased mitochondrial biogenesis. Now I can run 10 seconds per kilometer faster.
I don't know if there's any sort of studies that have correlated those two things, although they probably is to be honest. But yes, I don't to wrap that up. I don't know. But mitochondrial are determined of the things that, [01:08:00] of our alk, our physiology that do determine performance and. I wanted to touch on this too because VO two max we like, obviously a elite athletes have higher VO two Maxs than like less trained individuals.
And VO two max is a predictor of performance, but not when we, if we were to take all a bunch of elite athletes that have the same VO two max. Lactate thresholds. Actually the bigger predictor of performance the athletes that have the higher lactate threshold, despite having the same vo O2 max have, are that's more predictive of performance.
So that's why I think lactate threshold is really cool because it's more of like a metric of physiology. It's like you can, it's like a. A window into the bioenergetics of our skeletal muscle because the less lactate or maybe the greater the clearance the more likely that's going to be associated with performance outcomes.
And on that note, I'm going way off of our original questions, but No, that's alright. There, [01:09:00] there was a meta-analysis done like a long time ago, like 19 something. That took all the training studies and looked at what training in increased lactate threshold and the more trained you were, the less the more you needed intensity to increase your lactate threshold.
Sure. Which this also just contradicts the idea of needing zone two to essentially build your aerobic base. 'cause your aro, this aerobic base idea is that you have, like, you're building, you're pushing your lactate threshold up. By working out below it and ballooning your lactate threshold up.
Whereas most of all of the evidence would suggest that you need to work out above your lactate threshold to pull it up. So we all want a higher lactate threshold, but we're, there's a hyper focus on that low intensity to basically like boost our lactate threshold when I think we need to work out above it to pull it up.
Dr Mike T Nelson: Yeah. Yeah, and I would agree, and most of the literature would say that [01:10:00] lactate threshold is probably the determinant of performance, which gets into the weeds of, oh, but if your VO two max is 30, by definition, your lactate threshold's not gonna be very high compared to someone who has a. VO two max of 65.
Right. So,
Kristi Storoschuk : oh, for, and the sa the training would stay the same regardless of if you're trying to increase your VH max or increase your lactate threshold. So they all physiology works in They're all related concert. They're all related. Yeah. The, when you're at the top, when you've maxed out your VO two potential, like that's where we, you add into the weeds of, but none of us are near that.
So we don't have to be concerned about
Dr Mike T Nelson: No, I equate it to people like. It's thinking about how big is your engine and how much of that performance can you exert over a period of time. Right? Right. So by definition, I want a really big ass engine and I want to be able to red line the shit outta that car.
Right. I wanna be able to run for extended periods of time at a very high output. And in terms of absolute speed, I can only get there by having a bigger engine. I'm not gonna do that with like a three cylinder [01:11:00] Yugo engine. Like you can max it out all you want and you're just not gonna go that fast.
And then there's even some interesting stuff with, I can't remember the guy who, he was an up and coming, I think it was a rider for the Tour de France who had one of the highest VO two maxes ever measured. And they, their prediction was that, oh my God, this guy's gonna be like the next Tour De France winner.
But his lactate threshold was relatively low. I think the argument was okay, it just hasn't really been trained. And they did, sounds like they did some intelligent training, but could never get his lactate threshold to be ridiculously high to match his VO two max. So there's some really weird case studies where it seems like.
You can't have the best of both worlds. Like you can't have a near world record VO two max and ridiculously high lactate threshold, and you've got other riders who have, again, these are all elite level people who have just absolutely freaky numbers. Anyway, have a little bit lower VO two max, still absolutely high.[01:12:00]
But seem to be able to get a lactate threshold much higher too. It's a, I think if it was sprinting, there's some stuff where you can either have a really good acceleration phase, but then your ability to hold top speed might not be as good. And then when you train your acceleration phase, your top speed tends to go down a little bit.
And again, this is at the elite of the elite level. So at the end when it seems like you've maxed everything out, there's these kind of appears to be these trade offs that kind of limit your absolute performance when you get near the end for some reasons.
Kristi Storoschuk : Yeah. I've never looked into that, but that's interesting.
Dr Mike T Nelson: Yeah. So I, again, I have no idea why, but. Awesome. Any parting words? If you, what would be like your, so someone who. Is recreational lifter is listening to this and they've decided they do wanna get better with their aerobic fitness, what would be like your top four tips you would give them related to what you know?[01:13:00]
Kristi Storoschuk : Four. Okay. Yeah. Well, I've mentioned this many times. Five, they can be things we've already
Dr Mike T Nelson: talked about.
Kristi Storoschuk : Yeah. So max out your, if you want. To max out your adaptation, I would think you would have to max out your recoverable volume zone three plus once you're there adding in some zone two. Sure. If you, if zone two is the only like endurance exercise you will do, then that's better than nothing.
So do that over nothing. But if you can push yourself harder, go for it. You don't have to deliberately stay in zone two for any sort of purported benefits. I would say that you want to just try and accumulate volume near VO two max. I think that's where most of the literature would suggest that's the best.
Where you get the greatest adaptation is just like time spent near VO two max. So yeah, doing intervals, whether that's running, biking, rowing. [01:14:00] Et cetera. Anything I think that gets your heart pumping. And if you like steady state exercise, like a 30 minute, pretty hard bout, then do that over like a super low intensity.
You, you might, if you like steady state over intervals, then you can get similar adaptations without like, killing yourself with an interval. I don't know. There's probably four in there if you'd pick
Dr Mike T Nelson: me. Five. Yeah, there's four. No, it's great. Awesome. Well, thank you so much. I really appreciate it.
And if you want to be found, where can people find more about you?
Kristi Storoschuk : Okay, wait I'll add, are you over training or are you undereating?
Dr Mike T Nelson: Oh yeah, nutrition's a big component. If you're
Kristi Storoschuk : not recovering from high intensity exercise, then you're probably just not feeding yourself enough calories and carbohydrates.
Dr Mike T Nelson: Yeah. Quick side note, I have seen that if people are really pushing VO two max outta patients, for God's sakes, don't do it in a caloric deficit. 'cause I've seen it just [01:15:00] tank people's outputs like much. Yeah. More than I would've ever believed. So I would double underscore that one. Yeah.
Kristi Storoschuk : Awesome. You, I'm most active on Instagram, probably Christie stores.
Check. I'm on LinkedIn. X. If you just look up my name, I'll, you'll find me. And I think I'm the only Christie stores truck.
Dr Mike T Nelson: Okay. Awesome. And we'll put links to all of that and thank you so much for all the great stuff and thank you so much for doing all your research and publishing that in the literature.
And I think it's open access, correct. So people can download it. Yeah,
Kristi Storoschuk : I think I have the full text. LinkedIn, my bio on Instagram.
Dr Mike T Nelson: Okay. Yeah. So they can definitely get it from there so people can go read all the data themselves. So, yep. Thank you so much. I really appreciate it. That was great.
Kristi Storoschuk : Thanks Mike.
It was great to come back Yeah. And chat.
Dr Mike T Nelson: Awesome. I know you gotta run to your meeting and hopefully the first part worked well and fingers crossed and I'll let you know.
Kristi Storoschuk : Yeah. Let me know.
Dr Mike T Nelson: [01:16:00] That was weird. I've never had that happen before. 'cause I always said it to auto record 'cause I get so paranoid about, or maybe it was just a slight.
Glitch in the internet or something like that. So
Kristi Storoschuk : yeah, hopefully just like ConEd out for a sec and then rejoined. I dunno.
Dr Mike T Nelson: Yeah. But
Kristi Storoschuk : all right. Lemme know. Awesome.
Dr Mike T Nelson: Thank you so much. We'll see you. Thank you. All right. Bye Mike. Bye.
Speaker 2: Thank you so much for listening to the podcast. We really, really appreciate it. Uh, huge thanks to Christie for spending her valuable time with us discussing the pros and cons of zone two. Uh, we'll put a link to her paper, uh, which is really, really good review. If you're looking for a one stop review of zone two training, I would highly recommend that you check it out.
Okay. And if you are interested in her info, we'll have all of her links down below. And then if you want her top four tips for better aerobics for lifting meatheads, you can sign up to the Flex four down below. [01:17:00] Also it's completely free and that'll put you on the Fitness Insider News list from me, and you'll get a lot more great info.
In addition to the past top four items from many of the other previous podcasts guests. Again, that content only goes out to the fitness insiders there, but it's completely free to join. So thank you so much for listening. If you want more from myself or Christie, we will be at the International Society of Sports Nutrition this June down there in, uh, wonderful.
Usually hot and humid Florida. At that time of year. So we'll put a link to that conference below. And as always, thank you so much for listening. We really, really appreciate it. Any comments or anything else, please let us know. If you enjoyed this episode, please forward it to someone or share it online and tag both of us so we can say thank you.
And as always, we'll have much more information coming up. [01:18:00] You can do us a favor and give us the old likes and subscribe and download and. Even leave us a review on the iTunes and Spotify and whatever platform you're listening to goes a long way to really help us with organic distribution of the podcast to keep growing the listener base.
Thank you so much, greatly appreciate it. Talk to all of you next week.
Speaker 3: Did you see that? Yes. The frog is certainly taking a beating on this show. Yeah. It's hard to feel sorry for him. We take a beating every show.
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