[Is Zone 2 Training Optimal for Mitochondrial Health? My Interview with Kristi Storoschuk](https://www.physiologicallyspeaking.com/p/is-zone-2-training-optimal-for-mitochondrial)

### Summary

* **Central Thesis:** The podcast discusses Kristi Storoschuk's narrative review, which challenges the popular claim that Zone 2 training is uniquely superior for improving mitochondrial health and fat oxidation in the general population.
* **Lack of Direct Evidence:** A primary finding of the review was the limited number of scientific studies that specifically prescribe and test "Zone 2" training. Much of the hype is an extrapolation from research on low-to-moderate intensity continuous training.
* **Mitochondrial Health:** While Zone 2 can improve mitochondrial markers (especially in sedentary individuals), it is not uniquely effective. Higher intensity exercise (anything above Zone 2) is consistently found to be equal or superior for driving these adaptations.
* **Fat Oxidation:** Zone 2 is not uniquely better for improving long-term fat-burning capacity. While more fat is burned *during* Zone 2 exercise, higher intensity training stimulates greater adaptations and can lead to equal or greater 24-hour fat oxidation due to post-exercise effects.
* **VO2 Max:** Higher intensity exercise is significantly more effective and time-efficient for improving VO2 max, a strong predictor of longevity and overall health.
* **Origin of the Hype:** The Zone 2 trend is likely based on observational data from elite athletes who follow an 80/20 training model (80% low-intensity, 20% high-intensity). However, this is seen as an *artifact* of their massive training volume (20-40 hours/week), not a direct prescription for the general population exercising only a few hours per week.

### Actionable Recommendations

* **Prioritize Intensity if Time is Limited:** For the general population exercising 150-300 minutes per week, focusing on accumulating "recoverable volume" *above* Zone 2 will likely produce better and more time-efficient results for mitochondrial health, fat oxidation, and VO2 max.
* **Don't Replace Higher Intensity with Zone 2:** If you are already doing moderate-to-high intensity workouts, do not replace them with Zone 2 based on the belief that it offers unique benefits. You may be limiting your potential for adaptation.
* **Anything is Better Than Nothing:** If you are currently sedentary, starting with any form of exercise, including Zone 2, is highly beneficial and a great first step.
* **Understand the "Intensity Threshold":** To stimulate significant physiological adaptations (like building mitochondria or improving VO2 max), your body needs a sufficient stressor. Aim for workouts that are challenging and push you above a low-intensity conversational pace.
* **Listen to Your Body:** The recommendation for higher intensity does not mean every workout must be maximal. Pay attention to your recovery, energy levels, and how you feel to determine if you should push harder or take an easier day.

### Key Quotes

> **I think that members of the general public should absolutely be trying to be above Zone 2 in every single bout of exercise that they do.** Because if you're training, I don't know, five, six hours a week, then you're probably not at risk of overtraining. Like, and it, again, like it doesn't, like you said, it doesn't mean necessarily high intensity interval training. It's literally anything above Zone 2.
>
> Like I would, my, I guess, recommendations, if I were to recommend anything based on what I've come to conclusion after this, writing this paper, is that accumulating, **you want to accumulate as much recoverable volume as you can above Zone 2 before even considering Zone 2**. And I just don't think we're getting to that threshold. I don't think people that are just exercising for health are getting anywhere close to that threshold for needing to add in volume via Zone 2, which means that we should just be prioritizing as much as we can intensity, which can totally fall within the heavy intensity domain. Zone 3, Zone 4, continuous training. It doesn't have to be intervals. It can be continuous training at a higher intensity.

For those training around five to six hours a week, overtraining is unlikely. The priority should be accumulating recoverable training volume at intensities above Zone 2, such as continuous training in Zones 3 and 4, before adding low-intensity volume.

### Transcript

00:00:02,119 --> 00:01:11,439 [Brady Holmer]
Hi, everyone. Welcome to Physiologically Speaking. Today I'm joined by Christie Storchuk. She is a PhD candidate in muscle physiology at Queen's University. She's studying HIIT, mitochondria, glucose, lactate, all types of things that we're all interested in, myself in particular. And the reason I invited her on today is because she recently authored an awesome review paper, and it was titled, cleverly, "Much Ado About Zone 2: A Narrative Review Assessing the Efficacy of Zone 2 Training for Improving Mitochondrial Capacity and Cardiorespiratory Fitness in the General Population." And we're gonna talk about that review today. We were talking offline and she mentioned how it ruffled a few feathers, which makes sense given the somewhat religious nature of training these days. We have, have the high-intensity interval training crowd and the, the Zone 2 training crowd, but we're gonna talk about her view and the implications of it. Are we over-hyping Zone 2? Should we be promoting high-intensity interval training more? But before we get into that, Christie, I just want to say welcome, and, um, can you give people some background into who you are and what you're doing, just briefly?

00:01:11,439 --> 00:01:56,659 [Kristi Storoschuk]
Totally. Hi. Thank you for having me, Brady. It's such a pleasure to finally be chatting with you. Um, and thank you for that introduction. So yeah. Like, like you said, I'm a PhD candidate at Queen's University in the Muscle Physiology Lab, and I'm studying the effects of nutrient timing and carbohydrate availability around high-intensity interval training and the effects on lactate threshold and determinants of lactate threshold, as well as whether we can use our lactate threshold, or Zone 2, as a functional marker of mitochondrial content. So it's not just like a functional test we can use to assess insight into our mitochondrial content. So that's kind of what my dissertation has wrapped, um, has kind of ended up as. And

00:01:56,659 --> 00:02:31,439 [Kristi Storoschuk]
this review is outside of my PhD dissertation, but it's something I'm, I'm very interested in because, like you, I'm just in this world of health optimization. I've been following these leaders in the science communication space for many years and idolized a lot of them, and still do. But when it came to things that I was studying and I was familiar with, I had questions about what was being promoted online and whether that lined up with the evidence. So specifically with this Zone 2 paper, if we wanna just jump into it. [laughs] I don't know, do you t- want me to?

00:02:31,439 --> 00:02:34,579 [Brady Holmer]
Yeah, let's do it. Let's go for it.

00:02:34,579 --> 00:04:51,159 [Kristi Storoschuk]
Yeah, like, there's lots of claims online that Zone 2 does certain things, and specifically... So our lab, we study mitochondrial adaptations to exercise, different modalities, intensities, and the claims online were that Zone 2 is this like unique intensity that promotes mitochondrial adaptations, makes us better at burning fat, so improves our fat oxidative capacity, and then there's other claims around it. But those are the two claims we specifically targeted for this review. And my motivation just came, I guess, from just questioning whether I needed to be doing Zone 2, because I really care about my mitochondrial health. I really care about my metabolic flexibility, my ability to burn fat, and this messaging was... It was, became very popular, and so I honestly just was asking the question like, "Do we have evidence to support these claims?" That was it. It wasn't like a, "Oh, should we be doing Zone 2 versus X, Y or Z?" It was really just like, "What evidence do we have to support Zone 2 improving mitochondrial capacity and fat oxidative capacity?" So that's how we addressed it, and we went through... We addressed the paper and the evidence by looking at things mechanistically and telling that story. So we are a molecular lab. The way we think about adaptations comes right, like, goes down all the way to the signaling pathways that activate those, those ada- that, those, um, adaptations that should promote that function that we're looking for. So whether that's a higher VO2 max or greater glucose tolerance or like the, the hard outcomes that we're looking at, and... Or I guess more specifically for this, is like mitochondrial content. So first you have a signal during exercise, then you get the activation of a pathway, and then you get increased protein content of that specific protein, and then you get the function outcome. So mitochondrial content would be the outcome of an increase in signaling. So that's how we kind of approached this, this paper. And honestly, it just, it was just months and months, maybe even up to a year, of just looking for papers that prescribed an exercise intensity that would be characteristic of Zone 2. So one of the primary takeaways from this, this paper

00:04:51,159 --> 00:04:53,519 [Kristi Storoschuk]
really was that

00:04:53,519 --> 00:07:14,631 [Kristi Storoschuk]
there's not many studies that use Zone 2. So the way we- that we define Zone 2 was based on popular media, so just below your first lactate threshold, which I'm sure lots of your listeners know what a lactate threshold is. But as we increase intensity, starting at a very low intensity, lactate will start, will stay low for a few stages as you increase intensity, but eventually it increases about one millimolar above resting, and that would be considered around your lactate thr- your first lactate threshold. Um, and then as you keep increasing intensity, you essentially reach your second lactate threshold, and above that it just is exponentially high, and as you increase duration above that lactate threshold too. And so la- uh, Zone 2 w- in the endurance world is defined as just below your first lactate threshold, so somewhere around 1.5, 1.7 millimolar of lactate within your blood, 'cause... And based on a lactate threshold 1 being around two millimolar, so just below that. Things that align with that threshold are our gas exchange threshold, so based on ventilation, and then also our fat max, which is similar to a lactate threshold test where you're increasing intensity and you find this peak fat oxidation before it declines and we start relying heavily on carbohydrates for metabolism.... that's your fat max before it keeps going up. Although, I think there's controversy around whether that truly is a fat max. Anyways, that could be, um, it corresponds with your first lactate threshold. So, those are how we use to define which we also use percent of VO2 max, which we used, uh, a cutoff that was based on another analysis by Coates et al, and it was 45% of VO2 max is what we considered the cutoff for zone two. So, with all that [laughs] we tried to find studies that fell within those categories, that looked at mitochondrial, that either looked at the signals that trigger mitochondrial adaptations, whether mitochondrial adaptations were actually turned on, and then whether there were any outcomes associated with mitochondrial capacity, so either mitochondrial respiratory capacity or just an increase in mitochondrial content. And, like, the results were that we really found very limited evidence that zone two actually

00:07:14,631 --> 00:07:57,351 [Kristi Storoschuk]
leads to these outcomes that are claimed online. There is evidence that it does occur, but it doesn't always. So, it's not that, like I'm definitely not under the impression that zone two is uniquely benefiting mitochondria and inducing mitochondrial adaptations and there's a chance that it's not. And then, when we compare to higher intensities, it's almost always inferior to higher intensities and that doesn't mean high-intensity interval training, although it could. It just means anything above zone two. So, that could be continuous training that falls within, uh, the modern intensity, uh, or the heavy intensity domain, which is what we use in exercise physiology, which would just be like zone three, zone four.

00:07:57,351 --> 00:07:58,191 [Brady Holmer]
Awesome. So-

00:07:58,191 --> 00:07:58,671 [Kristi Storoschuk]
[laughs]

00:07:58,671 --> 00:08:26,531 [Brady Holmer]
... if we then back up a little bit. So, we're kind of, you came to the main conclusion, zone two, at least is inferior to higher intensities. Did you find evidence that zone two does actually improve though, mitochondrial biogenesis, whatever kind of measures you're looking at? And maybe there were particular measures that like stuck out there? You know, you talked about how you're particularly interested in the signaling pathways there and so is there evidence that zone two intensities improve that at all?

00:08:26,531 --> 00:09:17,431 [Kristi Storoschuk]
Yeah. There was one or two studies, um, that showed an increase in citrate synthase activity which is a marker of, or one study that showed citrate synthase activity go up with a zone two training protocol in overweight, sedentary adults. Um, and then the, but there was plenty, like a handful of other studies that showed no change in mitochondrial outcomes, um, in like more trained individuals. So, there is evidence, I guess, that it does increase mitochondrial content, but there's also evidence, there was a- another study out of, it was Granada et al, David Bishop's lab, and they compared basically zone two. It was like just below, it, well, it was zone two. It was steady state, continuous training, HIT and SIT, and looked at mitochondrial respiratory capacity, so that would be more of a measure of function versus what we would-

00:09:17,431 --> 00:09:17,451 [Brady Holmer]
Hmm

00:09:17,451 --> 00:09:43,751 [Kristi Storoschuk]
... say is content. And, I don't think there was any change with, with the zone two group, but there was with the HIT, or maybe there was only with the SIT or something, it was something a bit odd, but no change with, with the zone two group. So, there's a chance that you're, you could be following a protocol that's not actually inducing a- mitochondrial adaptations, but there is evidence in sedentary, overweight individuals that it could.

00:09:43,751 --> 00:10:00,571 [Brady Holmer]
And I think, you know, I think that's a key distinction, is like what, what populations are, are we talking about? And for your review, you basically focused, was it mainly on, say untrained, recreationally trained people, as opposed to elite or like well-trained athletes, right?

00:10:00,571 --> 00:10:08,511 [Kristi Storoschuk]
So, we, our review, yeah, I should've disclaimed this from the beginning. It really does come from the perspective of recommending zone two to the general population.

00:10:08,511 --> 00:10:08,631 [Brady Holmer]
Mm-hmm.

00:10:08,631 --> 00:10:22,871 [Kristi Storoschuk]
So, someone who's just following the physical activity guidelines, 150 to 300 minutes per week, should we be prioritizing some of that time to zone two? Are we getting these unique benefits from zone two training? However, we pulled any evidence that we could find.

00:10:22,871 --> 00:10:22,891 [Brady Holmer]
Hm.

00:10:22,891 --> 00:11:06,031 [Kristi Storoschuk]
So, whether it was in elite athletes, whether it was in just recreationally trained, whether it was in sedentary individuals, the question still remained, like does zone two do this? So, we pulled from, there was honestly like the, the evidence was, there's so many li- like there's no studies that we could really find, like there's kind of crazy studies that were like ski expeditions for 50 days where they're skiing at a very low intensity for like six hours a day, and then take- taking a muscle biopsy after this ski expedition and tracking their heart rate throughout, and just no changes or even declines in mitochondrial capacity. So, those, we're pulling from whatever evidence we could find, and which kinda,

00:11:06,031 --> 00:11:28,311 [Kristi Storoschuk]
that in itself was a bit crazy just 'cause the, the messaging online is so confident that, like, "Oh, we need zone two because it improves our mitochondrial health, and we, mitochondrial health are so important for metabolic health so we have to be doing zone two training for this." And, yeah, that was one of the most eye-opening takeaway was like, "Where is this coming from?" [laughs] Which, I mean, I guess we could talk about that, like where-

00:11:28,311 --> 00:11:28,891 [Brady Holmer]
Yeah, let-

00:11:28,891 --> 00:11:29,571 [Kristi Storoschuk]
... is this coming from?

00:11:29,571 --> 00:13:19,619 [Brady Holmer]
Yeah, let's definitely talk about that, and that, this cr- that, Kristi, has always been one of my, why this whole zone two thing came into being so popular and, yeah, we'll definitely talk about like where this all originated. But, I was always just surprised by the fact that, you know, from my perspective, and being, you know, I've, you know, exercise science degree as well, and just, I've done, I've read so much literature on training, and anything basically is, that you look at it, that would be considered zone two, it's always, it's moderate intensity, low or moderate intensity training. That's kind of what people are inferring zone two is. So, as you just mentioned, like there aren't really any studies that specifically say, "We train participants in zone two." It's always just low to moderate intensity exercise, and that somehow has been extrapolated to being zone two training, and then anybody citing any evidence, like, "If it's not HIT, that means it's zone two." There's just like these two poles of it which...... never made sense to me at all. So that was one of the reasons why I was glad you even did this review in the first place, and just to show that there's just not really studies looking at actual Zone 2 training. We can define it in these multiple ways, but when it comes down to it, like there's not really that much evidence to say we're confident that actual Zone 2 training is kind of what's leading to these benefits. But yeah, let's talk about w- you know, where the heck, where the heck did Zone 2 [laughs] become so popular? I mean, I know, you know, Dr. Peter Attia in a couple podcasts with Inigo San Milan, they talked about Zone 2 training and all of the benefits, and obviously like a lot of evidence discussed there, none of which I'm discrediting. So, kind of stemming from, you know, probably the podcast and like the health space for Zone 2, but it kind of stems from this whole 80/20 principle in elite athletes. So why don't you kind of walk us through that, and, um, what's sort of the premises where, you know, the recommendation for doing all this Zone 2 training came from?

00:13:19,619 --> 00:15:00,979 [Kristi Storoschuk]
Yeah. And again, I'm just speculating here because we don't really have concrete evidence to say like why, where this all came from, but I'm definitely under the impression that this is all just based on observational data in elite athletes who have huge training volumes of which 80% that you mentioned is spent in Zone 2, so just below lactate threshold one, whereas the 20... That, the other 20% is spent at high intensities. But, the, I guess the major caveat of that is that these elite athletes have, are training for like 20 to f- up to 40 hours a week. So, 20% of that at high intensity is still a huge amount of high intensity. And then the proponents of Zone 2 are attributing their... They also have high mitochondrial content, high mitochondrial capacity. They're metabolically healthy, insulin sensitive, so all of these things are lining up. Like they do a ton of Zone 2, they have good mitochondrial fat oxidative capacity, and are likely in good metabolic health. But, we're attributing based on this correlation that they, they do these things. We don't have any experimental evidence to say that following Zone 2 protocols result in those outcomes. So we're just extrapolating from what elite athletes do and then generalizing it to members of the general public that likely have a very small percentage of a training volume to these elite athletes, when also all the basic science and molecular science would suggest that maybe all their adaptations are driven through that h- that 20% of high intensity. I'm not saying it is. I'm not saying it's not the Zone 2 or whatever. It's just like, maybe playing devil's advocate, maybe it's the 20%. [laughs]

00:15:00,979 --> 00:16:15,079 [Brady Holmer]
Yeah. I mean, I think that, again, we don't have any data to support that, but I'm kind of in agreement with you. I think that the 80/20, and I've always said this and I've kind of gotten pushback from th- against this as well, but like, the 80/20 just tends to be an artifact of their high volumes of endurance training rather than an actual prescription. You know, they don't set out to do 80/20. It just results in that because when you're training for 30 hours per week, you just simply can't do all that high intensity interval training or you're going to "burn out", which we really don't, you know... Or overtrain. We don't have a definition of that. So, it's more of an artifact. It's something that these elite athletes have just a pattern that they fall into. I mean, even if I look at my own training, and I'm not training 20 hours a week but it's probably 12 to 15, I don't set a prescription at the start of the week to do X amount in Zone 2 and X amount of high. But at the end of the week, lo and behold, it ends up being somewhere around that 80/20. So, to me, it's, I think, a lot of the adaptations, as you mentioned, are being driven through HIT. Certainly there's a supportive role of Zone 2. We're not saying it's obviously useless, like that extra 15 whatever hours a week, but yeah, if you, if you even took that 20% of what the high, the elite athletes are doing,

00:16:15,079 --> 00:17:00,659 [Brady Holmer]
just that four to five hours per week of high intensity is just more exercise alone than most of the general population is doing at all. So, that's where it comes down to, which, you know, you mentioning review, if there's a population only doing 150 to 300 minutes per week, why can't more of that be... Should more of that be high intensity to kind of drive these beneficial adaptations? Like, do you, do you have thoughts there? Because I know there is a lot of pushback when you promote, you know, everybody should just be doing HIT like two to three times a week, and not, and not HIT per se, but like not as low as Zone 2 training. Like, if people are actually trying to get these adaptations, you know, could there be an argument for doing more high intensity training and what perhaps are the downsides to doing so? [laughs]

00:17:00,659 --> 00:17:09,119 [Kristi Storoschuk]
Yeah. I think that members of the general public should absolutely be trying to be above Zone 2 in every single bout of exercise that they do.

00:17:09,119 --> 00:17:09,179 [Brady Holmer]
Mm-hmm.

00:17:09,179 --> 00:20:06,019 [Kristi Storoschuk]
Because if you're training, I don't know, five, six hours a week, then you're probably not at risk of overtraining. Like, and it, again, like it doesn't, like you said, it doesn't mean necessarily high intensity interval training. It's literally anything above Zone 2. Like I would, my, I guess, recommendations, if I were to recommend anything based on what I've come to conclusion after this, writing this paper, is that accumulating, you want to accumulate as much recoverable volume as you can above Zone 2 before even considering Zone 2. And I just don't think we're getting to that threshold. I don't think people that are just exercising for health are getting anywhere close to that threshold for needing to add in volume via Zone 2, which means that we should just be prioritizing as much as we can intensity, which can totally fall within the heavy intensity domain. Zone 3, Zone 4, continuous training. Doesn't have t- it doesn't have to be intervals. It can be continuous training at a higher intensity. But I... For example, there was a recent study that just came out of the University of Calgary, and it's really awesome. Looked at Zone 2 versus just above Zone 2 within the heavy intensity domain, and then another group within the heavy intensity domain but with, but at the upper boundary. So, Zone 2, lower boundary heavy, high b- boundary heavy, HIT and SIT. All the groups were work matched except for the sprint interval training 'cause you can't really work match SIT. And I-All the thresholds, so maximal lactate steady state, lactate threshold one and VO2 max, they all increased in the groups that were above zone 2. The zone 2 group didn't change from... Wasn't different from the control group after the six weeks of training, but all the other groups had improved. So it, that almost implies that, like, that is the threshold for which we want to be above if we want to improve these determinants of not only performance, but health. Or not only health, but performance, if I wanna put it that way, for members of the general public. And, uh, and also meta-analyses. So another 2018 meta-analysis by Granata, et al, they, they looked at, uh, um, training intensity and volume on specifically mitochondrial outcomes. And the results of that study, it included f- 57 training studies. And they suggest that anything below 60% of work rate max, which is likely above zone 2 for most just recreationally active, sedentary people, even increasing volume below that threshold or at that threshold wouldn't be expected to increase either mitochondrial content or mitochondrial capacity, respiratory capacity, which suggests that there might be this threshold for which we want to be above in order to induce adaptation. So with that, with meta-analyses, um, there's also the Mohlman, um, meta-analysis that maybe you saw [laughs]. That's what, uh, triggered this interview-

00:20:06,019 --> 00:20:06,179 [Brady Holmer]
Mm-hmm

00:20:06,179 --> 00:20:38,299 [Kristi Storoschuk]
... was, like, yeah, we can get similar adaptations with continuous training, but it's likely that it's above, it has to be zone 2 for you to get the similar outcomes as high-intensity interval or sprint interval training. So there might be... It's possible that there's a threshold for which we wanna accumulate volume above in order to get those adaptations. And so when it comes to, I guess, trying to figure out what the, uh, general public should do and what... Worrying about intensity, I think it's just like, don't worry about-

00:20:38,299 --> 00:20:38,319 [Brady Holmer]
Hmm

00:20:38,319 --> 00:21:12,519 [Kristi Storoschuk]
... purposely going low. If you prefer... So here's where, what I'll say. If you're going from nothing to zone 2, amazing. You're likely gonna improve, your health outcomes are going to improve. That's so awesome. And anything is better than nothing. However, if you're replacing your higher intensities for zone 2 because you're buy-in to the, "I need to be doing zone 2, for certain outcomes that are claimed online," then that's where I guess I draw an issue with, just because you might be limiting your potential for adaptation and performance and health outcomes.

00:21:12,519 --> 00:21:26,259 [Brady Holmer]
No, I love that. I think the two important things that you mentioned there that I like that idea of the maximum recoverable volume. So, like, if you're below some volume threshold per week, who knows what that is, maybe it's somewhere around 300 minutes, but, like-

00:21:26,259 --> 00:21:26,279 [Kristi Storoschuk]
Yeah

00:21:26,279 --> 00:22:36,279 [Brady Holmer]
... until that, like, don't really focus on purposefully lowering your intensity, because you're likely recovering from exercise session to exercise session. It's like there's just this, there's this thought out there for some reason that, like, everybody's, like, gonna overtrain or something. And that s- it's so just rare. I mean, of course it can happen, because if people aren't professional athletes, they have full-time jobs and they have children, and, like, you add training on top of that. And sure, it can be a lot. But I just think that, I don't know whether it's coming from coaches who are just used to people just, uh, you know, athletes training an absurd amount, where they're like, "Oh, you can't do too much intensity or you'll burn out." But I just think that for most people, like, if you're exercising once a day every single day, you're recovering from, from one session to the next most likely. And of course there are outliers and that's not true for everybody, but I love that idea of the maximum recoverable volume in that, this threshold of intensity. Because again, like, going back to the cellular mechanisms, you have to cause a sufficient stress in the body to, like, kickstart these signaling pathways. And so there really is an intensity in that, where that switch, for lack of a better word, is, is turned on. So I think those are definitely good ideas. And yeah, if people are...

00:22:36,279 --> 00:22:51,459 [Brady Holmer]
If you're really not, you know, doing probably more than, I like to say, like, five to six maybe hours per week, don't, like, purposefully focus on limiting intensity. I feel like that's a pretty straightforward and rational recommendation that you just gave. So I like that a lot.

00:22:51,459 --> 00:22:55,159 [Kristi Storoschuk]
And, like, I will say, like, you're allowed to listen to your body. Like if-

00:22:55,159 --> 00:22:55,359 [Brady Holmer]
[laughs]

00:22:55,359 --> 00:23:06,659 [Kristi Storoschuk]
... if you feel like... I know when I'm doing too many high-intensity training sessions back to back. If I do two a days, back to back to back, I can feel it. So [laughs]-

00:23:06,659 --> 00:23:06,679 [Brady Holmer]
Yeah

00:23:06,679 --> 00:23:29,659 [Kristi Storoschuk]
... like, you, you're, you're allowed to be like, "I actually don't have the power and strength in my legs today to keep going, so I'm gonna go easy today." Or take the day off, whatever it is. Like, I don't know what that, that recoverable, recoverable volume is for each person, but I... 'Cause I think it's just gonna ba- be based on person to person. Yeah, like, listen to your body. Do you feel [laughs], like, you can keep going or not?

00:23:29,659 --> 00:24:26,559 [Brady Holmer]
Yeah. Novel advice, right? To listen to your body. It'll tell you, it'll tell you all you need to know. The final thing regarding volume, kind of before I wanna move on a little bit, is that there's sort of this, again, maybe misconception that I don't think has a lot of evidence to, to support it, is that these higher intensities and doing a lot of them is, is somehow unsustainable. So you referred to that Mohlman meta-analysis that just came out. That was, like, one of my favorite papers in the last, you know, few years to come out, just because I think it provided a lot of interesting stuff on mitochondrial improvements, VO2 max from HIT modern intensity training. But there were some great graphs in there, and it basically would show us that when it comes to the high-intensity studies, very few of them last longer than 8 to 12 weeks. And a lot of people use that paper as the argument that, "Oh, moderate is better, because if you extend out that curve for the long term, that's where it's going to lead to sustainable improvement to VO2 max. And, and high intensity isn't sustainable for the long term." Do you think that there's a lot of evidence to, to support that statement at all?

00:24:26,559 --> 00:25:49,823 [Kristi Storoschuk]
No. Like, there are long-term trials in individuals that are metabolically impaired or in, uh... There's six-month trials in cardiac rehab patients. Um, we've had six-month trials in our own department, um, in individuals who are overweight or obese that are exercising day in, day out at a what's high intensity to them, which honestly in those individuals was just brisk walking. But that's 75% of their VO2 max. Um, so...And, um, to, the idea that it's unsustainable is, I don't think is supported. There are also over-training studies. They're short-term, but doing two-a-days for 20 days consecutively, and they're trying to overtrain them, and every 10 days were assessing for overtraining and they weren't getting overtrained. I mean, it's, that's just three weeks, so it's not, I'm not necessarily saying that that's supporting this idea. But, um, but I think it would take a lot to, to get to that point of it being unsustainable, and I don't think everyone's just doing crazy HIIT sessions five days a week. Like, if, if we're, if we're just exercising for health, we're probably adding in some days for resistance training and we're having days off between our aerobic exercise training. So, I don't know. But, I mean, I wouldn't even say that you couldn't do it five days a week. [laughs] You might, you might be able to get away with that.

00:25:49,823 --> 00:25:55,943 [Brady Holmer]
Yeah, you might, you might be able to, de- depending on your volume. But, yeah, I would totally agree, and this is kind of where the

00:25:55,943 --> 00:26:30,503 [Brady Holmer]
clinical and gen- uh, training for general fitness kind of differs from the athletes' training. You know, when I was like in graduate school, again, we did, you know, plenty of studies where you have people with diabetes who are 50 or 60 years old coming in and doing the Norwegian four-by-four, like, two to three times per week. It's like they're not overtraining. They're able to do it. I mean, certainly it's not easy, but there are plenty of studies showing for up to, like, six months, you know, be sustainable. Um, I would, you know, I think it's, whether it's smart or not, you know, who knows? But I think just to say that, "Oh, it's not sustainable and moderate is better," isn't necessarily the, the correct con- conclusion to make there.

00:26:30,503 --> 00:26:35,103 [Kristi Storoschuk]
Yeah. And again, like, I just come back to, like, this isn't Zone 2 versus HIT. It's like-

00:26:35,103 --> 00:26:35,263 [Brady Holmer]
No

00:26:35,263 --> 00:26:37,063 [Kristi Storoschuk]
... what's wrong with continuous training at-

00:26:37,063 --> 00:26:38,423 [Brady Holmer]
It's not either/or, right?

00:26:38,423 --> 00:26:39,083 [Kristi Storoschuk]
Yeah, yeah.

00:26:39,083 --> 00:27:37,383 [Brady Holmer]
Totally. Yeah, and I think we already mentioned this, but HIT doesn't just, it doesn't always mean high-intensity interval training. It just means anything above Zone 2, which there are a lot of, you know, Zone 3, 4, and 5. You can do a lot of things. Thr- threshold training falls under that umbrella as well. So, I want to talk about fat oxidation for a minute, and I think, you know, similar to the mitochondrial benefits, your review came to the similar conclusion, obviously, that Zone 2, you know, may improve fat oxidation. Probably inferior to high-intensity interval training. But there's this interesting kind of paradox almost, where during Zone 2, I think, and correct me if I'm wrong, but there, the rate of fat-burning is higher during Zone 2 exercise compared to, say, something like higher-intensity interval training. But, that doesn't appear to necessarily result in the same, you know, long-term enhancement in fat oxidation. Can you kind of explain that and what you, what your review found regarding that?

00:27:37,383 --> 00:29:41,483 [Kristi Storoschuk]
Yeah. Um, I mean, I'll take a step back and just, like I have always wanted to believe that burning fat during exercise improved fat-burning capacity. I've switched up things in my life to do things, like that's what I, my hypotheses around fasted training have been because you're burning more fat, so X, Y, Z. You get fasting, you're burning fat, blah, blah, blah, blah. Anyways, with Zone 2, it kind of falls within that same kind of idea that you're burning fat, so you should be getting better at burning fat. But, mechanistically, we want to exceed capacity in order to tell our body to adapt, 'cause we adapt to stress, so that the next time we do that same stressful event, exercise, we're better able to... Essentially, it all comes down to matching ATP synthesis to ATP demand, so we do, at low intensities, we can meet the demand for ATP very easily through aerobic metabolism, through fat oxidative metabolism, and then as we increase intensity, we start accumulating AMP and ADP because we just simply can't match the synthesis through aerobic metabolism. So, that's when we turn on carbohydrate metabolism, eh, through glycolysis and also break, the breakdown of muscle glycogen. And so then we start burning more carbohydrates relative to fat as we increase intensity. I don't, but aerobically, we're still maxing out. We're still increasing our aerobic metabolism. It's just coming from carbohydrates now instead of fat. So, I think that's, I think that's kind of telling, like putting a pin in, or a, I don't know, breaking this storyline of like, "Oh, we need to burn fat and so that would improve fat oxidative capacity." But it's, it's just a- aerobic metabolism. Those are the, that's, that's the same machinery that burns fat, that burns carbs, just aerobically. So, burning carbs isn't necessarily turning off our aerobic metabolism. If, if anything, we're increasing up until we no longer can exercise, uh, or produce, um, ATP aerobically.

00:29:41,483 --> 00:30:18,123 [Brady Holmer]
Yeah, I mean, that's such an important thing to know. It's like, if you start producing, and, you know, I'll use the term incorrectly here, but anaerobic energy production, or, you know, if you, once you've started oxidizing carbohydrates when your exercise intensity gets to this, you know, a high enough point, well, that, that means you've maxed out fat oxidation. And I do think that there probably is a point where if you're at such a high exercise intensity, you're probably not burning a lot of fat, or maybe your fat ox rate goes down, but yeah, if you're... It's gonna keep going up and up and up as the inten- exercise intensity goes up, and

00:30:18,123 --> 00:30:30,183 [Brady Holmer]
like you mentioned with the mitochondrial adaptations, okay, well, where do we burn fat? We burn fat in the mitochondria. Whatever exercise you do that's going to improve your mitochondrial capacity, well, that's gonna make you a better fat burner, right?

00:30:30,183 --> 00:31:20,939 [Kristi Storoschuk]
[laughs] Yeah, like, we have lots of evidence to support the use of high-intensity training to up-regulate the adaptations that support greater fat oxidative capacity, so whether that's enzymes involved in the breakdown of fat, transporters involved in bringing fats into our mitochondria, both capillary density, so bringing, or delivering oxygen, 'cause we need oxygen to burn fuel as aerobically. So, we have lots of evidence that supports the use of high-intensity exercise for doing that, and I will say that with our review, we found very mixed results for whether Zone 2 vers- compared to higher intensities what the outcome really is. Meta-analyses would suggest in favor high-intensity exercise, but there's a handful of individual studies that show same outcome, maybe s-... the lower intensity could be superior for one outcome, but I think on a whole, one, there's definitely not strong evidence to suggest-

00:31:20,939 --> 00:31:20,959 [Brady Holmer]
Oh

00:31:20,959 --> 00:32:04,939 [Kristi Storoschuk]
... that zone two does something unique that high intensity couldn't do. And, and then on a whole mo- uh, meta-analyses suggests that either you're getting the same outcome as moderate intensity continuous training on fat ox outcomes or favoring HIT, especially when we consider time. So, if you're only gonna dedicate a certain amount of time to exercise, that's when high intensity exercise really shines. And that's, again, just coming back to my, like, "Oh, it's not low intensity versus HIT." It's like if you're considering the best bang for your buck, then high intensity is usually gonna come out on top. And so yeah, with fat ox capacity, there is evidence that zone two can improve it, but not uniquely than what you wouldn't be able to get with high intensity training.

00:32:04,939 --> 00:32:13,979 [Brady Holmer]
Got it. So last thing I wanna talk about is cardiorespiratory fitness or VO2 max, which is kind of another popular outcome people are interested in. And

00:32:13,979 --> 00:32:15,239 [Brady Holmer]
let's just, you know, get straight to it.

00:32:15,239 --> 00:32:16,439 [Kristi Storoschuk]
Oh, wait, Brady, I'm gonna interrupt you.

00:32:16,439 --> 00:32:17,079 [Brady Holmer]
Yeah, please do.

00:32:17,079 --> 00:32:33,439 [Kristi Storoschuk]
I do, I did wanna add one more thing that I, I never really talk about this, but it's something I think about. Um, with high intensity interval training, we're still burning or we're still breaking down our fat in our adipose tissue. It's just not entering our bloodstream because-

00:32:33,439 --> 00:32:33,499 [Brady Holmer]
Mm-hmm

00:32:33,499 --> 00:33:28,559 [Kristi Storoschuk]
... blood flow is go- being directed to our muscles. But then post-HIT or post-high intensity training or exercise, we get this influx of fatty acids because now blood flow has resumed. We have the proteins that it needs to bind to in order to get in trans- uh, transferred in the body. So, it's not that we're not breaking down fats during high intensity exercise, it's just we're not oxidizing them acutely. But then post-exercise, we get that elevation of fat oxidation. And then overall on a 24-hour period, modern intensity continuous training that burns more fat during, there's no difference in the 24-hour fat oxidation. So, I always thought that that was really cool that we're, we're just basically trapping fatty acids in our adipose tissue until we're done exercising. Then blood flow then can allow for the delivery of those fatty acids around the body. And we are still gonna burn them, or I guess we're gonna, we would resynthesize them into triglycerides. But yeah, I wanted to mention that.

00:33:28,559 --> 00:33:44,399 [Brady Holmer]
No, yeah, that's fa- I mean, that's fascinating and important for people to note. So it's like over, if you look at a 20, over a 24-hour period, or heck, even extended up to a week, it's like your total amount of fat burned might just be the same. Just during that exercise bound literally is different.

00:33:44,399 --> 00:33:45,439 [Kristi Storoschuk]
Yeah.

00:33:45,439 --> 00:33:45,499 [Brady Holmer]
Yeah, no-

00:33:45,499 --> 00:33:47,159 [Kristi Storoschuk]
Anyway, sorry. We can go back to the other-

00:33:47,159 --> 00:34:29,039 [Brady Holmer]
No, I, thanks, thank you so much for adding that 'cause I think that, I think that's important to know regarding this whole, whole fat burning thing. And I guess, okay, one more thing before we move on then is like, and this is a genuine question that I'm asking, uh, you, is like, you know, why, why do we wanna be better fat burners? Why do you think people are so interested in, in burning fat? Because I think based on what all we know is, if burning more fat during exercise doesn't really mean you're losing more fat. So I don't think that that is a necessarily, necessarily like well-cited outcome. But like in general, like what's the, you know, if I become a better fat burner, what's, what's the advantage to me as say, an athlete or even if I'm a recreationally active person? You know, what's, what's the benefit there?

00:34:29,039 --> 00:34:34,359 [Kristi Storoschuk]
No, that's a good question. It's kind of like asking like, "Oh, you're already healthy. Why are you trying to improve your glucose tolerance"-

00:34:34,359 --> 00:34:34,419 [Brady Holmer]
Mm-hmm

00:34:34,419 --> 00:34:46,359 [Kristi Storoschuk]
... type thing? Like what... Yeah. Um, I think, I think this is gonna be speculation. I think it comes from the literature on people with metabolic syndrome-

00:34:46,359 --> 00:34:46,379 [Brady Holmer]
Mm-hmm

00:34:46,379 --> 00:35:55,719 [Kristi Storoschuk]
... not having the capacity to burn fat when they should. So those are the... That would be our example of someone who's metabolically inflexible, where they're insulin resistant, so they're not responding to an elevated glucose and insulin response, and not being able to upregulate carbohydrate metabolism in response to that. And then on the flip side, when they go from rest to exercise when we should be able to increase fat oxidation, individuals with metabolic syndrome have an impaired ability to upregulate fat oxidation. So, I think the idea is that like, oh, it's impaired in chronic, in states of chronic disease, metabolic chronic diseases, so therefore, we want to increase our capacity to burn fat if we want to lower our chances for chronic disease. Inherently, if we're exercising on a regular basis, we should be... Have the capacity to burn fat. And at rest we should be mostly burning fat, whereas those who have a impaired capacity, um, are burning maybe relatively more carbohydrate. So, I think that answers your question of like are, are, we wanna become fat burn- better fat burn- well, I will say this. From the perspective of health, that would be my answer.

00:35:55,719 --> 00:35:55,979 [Brady Holmer]
Mm-hmm.

00:35:55,979 --> 00:36:10,099 [Kristi Storoschuk]
From the perspective of an athlete, you want to have high capacity for fa- fat oxidation because in theory, that should delay, um, glycogen breakdown. So you, you are, you could probably explain this all better than I could, but yes, we wanna-

00:36:10,099 --> 00:36:18,879 [Brady Holmer]
That's what, that's what I always thought, but I don't even know if like the data backed that up now. And, and if I think about like, I guess the sporting type matters, but

00:36:18,879 --> 00:37:13,519 [Brady Holmer]
I don't know if necessarily being a better fat burner or burning more fat during exercise delays glycogen breakdown. Nor do I think that, you know, if I'm, if I'm running a marathon or something, majority of my energy contribution is probably coming from carbohydrate anyway. So I don't know if, if being a better fat burner necessarily helps me during that. I think maybe you can make a case for say like an ultra-marathon runner. You know, we were talking about Zach Bitter a little bit offline and like if you can burn fat better over 100 miles, then yeah, maybe he has to fuel less with exogenous carbohydrates. But I guess it depends on what kind of athlete you are in terms of, you know, what, what your sporting discipline is. So I guess there, there is, probably is a good reason. So I'm not saying it's not important to be a fat burner, but athletes in general tend to be good fat burners anyway. So I don't know whether getting much better through things like fasted training or whatever is, is necessarily like a net benefit. There's a lot of controversy-

00:37:13,519 --> 00:37:13,539 [Kristi Storoschuk]
I know

00:37:13,539 --> 00:37:15,459 [Brady Holmer]
... around that. We could probably talk about that for, for hours.

00:37:16,279 --> 00:37:18,339 [Kristi Storoschuk]
[laughs] My head's up in the air with all this stuff right now.

00:37:18,339 --> 00:37:18,380 [Brady Holmer]
Oh.

00:37:18,380 --> 00:37:29,759 [Kristi Storoschuk]
I'm, I'm trying to better understand it all at the moment because, yeah, like, most of the recent, I guess, messaging around athletic performance would be like, "W- why not just maximize carbohydrate metabolism?"

00:37:29,759 --> 00:37:29,779 [Brady Holmer]
Mm-hmm.

00:37:29,779 --> 00:37:37,779 [Kristi Storoschuk]
Like, it's a quicker f- it's a quicker fuel source, like, just take in carbohydrates during exercise and... Yeah, so I don't know. I don't know. [laughs]

00:37:37,779 --> 00:37:41,339 [Brady Holmer]
They'll give you diabetes, don't you know?

00:37:41,339 --> 00:38:06,439 [Brady Holmer]
All these marathon runners are dropping dead of diabetes 'cause they're fueling with gels. Okay, so last thing I wanna talk about, VO2max, 'cause it's something people are interested in and sort of, I think, the two areas, you know, you mentioned the mitochondria and fat oxidation in your review, but people are also interested in, like, there's a whole debate on whether, you know, is, does Zone 2 improve VO2max compared to HIT? And I think I know the obvious answer there but, you know, what did you, what did you find based on your review?

00:38:06,439 --> 00:38:54,299 [Kristi Storoschuk]
Yeah. I mean, ultimately, the reasons that Zone 2 is being promoted to just gen pop and popul- and within popular media is for improved health. And when we think about the things that improve our health, well, VO2max is a much stronger predictor of all cause mortality and disease risk than something like mitochondrial capacity or fat oxidative capacity. And so when we think about it that way, then we would be... It's very hard to convince someone that you should be doing low intensity exercise. We have s- very strong evidence that high intensity exercise leads to greater improvements in VO2max. Um, so if we're trying to just promote overall health, then prioritizing intensity would be the one thing that makes the most sense. Um,

00:38:54,299 --> 00:40:25,639 [Kristi Storoschuk]
yeah, I g- uh, well, I guess, to answer your question of, like, do we have evidence that Zone 2 increases VO2max, there is, I guess, some evidence in sedentary populations. However, there's also evidence, like I said, with the first, that other paper from University of Calgary, where they, uh, like, they had a deliberate Zone 2 group and then everything above. There was no difference in VO2max compared to the control group. And then we also have a long trial out of our department at Queen's University, and you either had to increase volume at low intensity, so duration, or increase intensity at a lower volume in order to get improvements in VO2max. And what was really unique about that study, one of the outcomes, was that in the high intensity group, so low volume, low intensity, high volume, low intensity, low volume, high intensity, the group that was in the, the high intensity, low volume group, as soon as you did intensity, there was, uh, they reduced the amount of non-responders. So people who didn't see an improvement in VO2max went to zero. Whereas the other groups, there were non-responders, which suggests that if we want to be, I guess, hedging our bets, like, best bang for our buck, like, let's try our best to improve our VO2max, then you'd wanna prioritize intensity. So, I would say that we just, the collective evidence is definitely favoring high intensity for improving VO2max, and that's a much stronger predictor for all cause mortality than anything else. So, real-

00:40:25,639 --> 00:40:25,799 [Brady Holmer]
Yeah

00:40:25,799 --> 00:40:27,119 [Kristi Storoschuk]
... research is really good.

00:40:27,119 --> 00:41:38,039 [Brady Holmer]
Absolutely. So I think that, of course people want to be aware of, you know, what, what outcome are you sort of trying to optimize for? But regardless, I think, of the outcome, based on all of this literature and your review, it would seem that doing HIT, whether it's, whether you wanna be a better fat burner, whether you want more mitochondria, whether you wanna improve VO2max, HIT tends to be better for doing that. Again, not to say you shouldn't do Zone 2, but yeah, everything that I've read, and I love that, I love those studies on the, the whole non-responders, and basically, like, if you're doing 150 minutes per week of just low to moderate intensity exercise, there are a lot of non-responders at that intensity, for both, I guess we were just focusing on VO2max, so aerobic fitness, but yeah, adding, basically you add HIT, everybody tends t- tends to respond. So, if you're looking to do more exercise and try to get your VO2max up, HIT seem, seems to be the way to do that. And yeah, lots of associations of VO2max with all cause mortality, though some people question whether that's causal, you know, whatever, but [laughs] it's a po- it's a potent, it's a potent marker there. So, yeah, Krissy, I think kind of l- all that I wanted to talk about. I'll, I'll refer people to your review and I'll link it in the show notes so that they can read it. I think it's open access, right?

00:41:38,039 --> 00:41:41,919 [Kristi Storoschuk]
There is an open access link. Um, you can find it somewhere.

00:41:41,919 --> 00:41:43,799 [Brady Holmer]
Okay. Well, people can find it or maybe, uh-

00:41:43,799 --> 00:41:44,539 [Kristi Storoschuk]
[laughs] They can link it.

00:41:44,539 --> 00:42:09,819 [Brady Holmer]
... yeah, email, reach out to you on social media for, for the paper. But I encourage everyone to read it. It was a very fun read. But final question that I have for you is kind of, in doing the literature search and maybe reviewing this evidence, did you, did you change your thoughts at all on how best to train, or perhaps like how, how to train yourself? Or did it kind of reinforce maybe what you were doing for yourself in terms of training in regards to, to intensity?

00:42:09,819 --> 00:42:11,699 [Kristi Storoschuk]
Uh, the latter, just reinforced.

00:42:11,699 --> 00:42:11,719 [Brady Holmer]
[laughs]

00:42:11,719 --> 00:42:26,499 [Kristi Storoschuk]
I'm, I'm, I'm more of a "I'm gonna do this workout. I don't even know if I can complete it, it seems hard, but I'm just gonna try my best" and I'm, yeah, I'm just like a "I'll go as hard as I can every day" type, type of exerciser.

00:42:26,499 --> 00:42:27,539 [Brady Holmer]
Well, I think there's, again-

00:42:27,539 --> 00:42:37,139 [Kristi Storoschuk]
And that's not, that's not gonna be end up super hard. I just, it's what I can tolerate that day but it's almost always most certainly above Zone 2.

00:42:37,139 --> 00:43:48,875 [Brady Holmer]
For sure. Well, and like you've mentioned earlier, I think everybody just, you know, listen to your body and find the exercise regimen that you seem, uh, seems to be sustainable. And, you know, I just think before we log off here it's important to note that we're not, you know, telling people not to do Zone 2. I do a lot of Zone 2. It's incredibly beneficial exercise intensity. And so, you know, you pointed out at the beginning, your review wasn't to say, "Ah, this is better. We shouldn't all be doing Zone 2," but it's just, I think it was a great experiment in evaluating the evidence and, like, having people question what, what is being promoted from podcasts or the quote unquote health influencers. You know, I don't really like that term, but some of this evidence in terms of how to train and how to eat comes from-... people not necessarily doing the research a lot of the times. And, and sometimes these ideas can catch on and we sort of just accept them. So, what I loved really most about reading this was that you questioned it, you investigated the question. You kind of found out that, well, maybe it's not totally wrong what's being spouted out there about Zone 2, but it's certainly not a foregone conclusion that if we wanna optimize our mitochondrial health, Zone 2 is the way to go. So, I think it's some very valuable information that you've added here.

00:43:48,875 --> 00:44:33,915 [Kristi Storoschuk]
Yeah. And, well, thank you for saying that. But I will... Like, again, it was like, I was just seeing everywhere that we needed to be doing Zone 2 for these outcomes, and I was literally tweeting out, like asking for studies. And I still like, I don't think... Like, people are just wanting to believe that it's doing something for these certain outcomes. And no one could, no one could provide me with a study. Like, there's no paper that someone could send me to be like, "Oh, look, here's the evidence that Zone 2 training does this. That's why I'm saying it." And so that was kind of eye- the most eye-opening start to this, and what motivated this review in the first place. 'Cause I'm like, "Where, where is the evidence? I want... I'll believe you if you provide a citation," but no one could do that for me, so that's where we landed.

00:44:33,915 --> 00:45:23,775 [Brady Holmer]
Yeah. Similar story with the whole 80/20 thing. Whenever that, whenever that ratio of this is what you should do for training is brought up, I always just go back to, okay, well this came from like a few studies that just said, "Let's break down the elite athlete intensity," and what does it end up being? 80/20. It was never, it was never a prescription from the outset. It was just like a pattern that was observed, which is probably a lot of what happens not just in maybe exercise science, but I'm sure in like nutrition epidemiology and other areas of science. I think this stuff happens a lot. So, you know, we just, we just need to be aware and, um, but it's a lot of fun to chat about this stuff and, um, so I appreciate you, you know, joining with me, uh, joining me today. And, uh, can you let people know where they can find you? I know you're on X, maybe you're on Instagram, but, uh, you wanna plug a few social media areas where people can, can find you?

00:45:23,775 --> 00:46:15,335 [Kristi Storoschuk]
Yeah. No, I just wanna say thank you for having me, first off. This has been really fun, and it's been fun to connect with you finally. And, uh, yeah, you can find me on X. I think it's K_Storjscheck. I hope you'll just link it. And then my Instagram is my full name, Kristy Storjscheck. And I will mention that we do have some really cool studies that are both wrapped up and are ongoing in our lab looking at Zone 2 training. So both in, uh, trained cyclists that just wrapped up, so stay tuned for the results where we l- the intervention was HIIT versus 80/20, and then we have that for just se- sedentary individuals, so HIIT versus 80/20 basically. So should, should we be extrapolating athlete population, what they're doing to general pub- public? And yeah, so that's the intervention. So it's gonna be fun to share those results in a long time when someone eventually does the Western blots.

00:46:15,335 --> 00:46:28,935 [Brady Holmer]
[laughs] Good stuff. Well, I was gonna say, I interviewed you too early, but I think it maybe will be a while before those are published. But, uh, when they are, I'll, I'll certainly have you back and we can, we can chat about those. I'm excited to hear that those are wrapping up and, uh, will be published at some point. Somebody finally-

00:46:28,935 --> 00:46:28,995 [Kristi Storoschuk]
Yep

00:46:28,995 --> 00:46:32,675 [Brady Holmer]
... doing the research that I want to be done. [laughs]

00:46:32,675 --> 00:46:34,895 [Kristi Storoschuk]
Yeah. We have a pretty fun lab.

00:46:34,895 --> 00:46:42,675 [Brady Holmer]
Totally, totally. I'm envious of the research that you're doing. I'm sure a lot of people would like to be doing that stuff. So, sounds like you're living the dream, uh, the exercise physiologist dream.

00:46:42,675 --> 00:46:45,255 [Kristi Storoschuk]
[laughs] Thanks. Yeah, it is fun.

00:46:45,255 --> 00:46:47,435 [Brady Holmer]
All right. Well, thanks a lot, Kristy. Uh, have a great rest of your day.

00:46:47,435 --> 00:46:49,155 [Kristi Storoschuk]
All right. Thank you, Grady. Yeah, you too.

00:46:49,155 --> 00:46:49,475 [Brady Holmer]
Bye.