How Intensive Exercise Reverses Cardiac Stiffness

Dr. Rhonda Patrick: And there's also studies showing that, you know, you can take, you can take a 50-year-old person who is sedentary, so they're, they're not physically active, but they don't have any other markers of disease. So they're not, you know, they don't have type 2 diabetes or cardiovascular disease or hypertension, and put them under a pretty intense exercise protocol for 2 years. And basically, you can reverse the aging of their heart by almost 20 years. So this study was done by Dr. Ben Levine out of UT Southwestern in Dallas, and what he showed was, you know, so as we age, our heart structure gets— it changes with time. So it gets— our heart gets stiffer and shrinks, and that plays a role in increasing our cardiovascular disease risk.

It plays a role in, you know, affecting our aerobic capacity. So, what he wanted to know, he asked the question, can I take these people that have essentially been sedentary their life, their whole life, but they're otherwise not, they don't have any identifiable diseases, and can I make their hearts look better? And so, his group put them on a pretty intense exercise protocol for 2 years, and it was a progressive loading. So, it wasn't like right out the gate, they were doing 5 hours of exercise a week, which is essentially what they were doing at the end of the 2 years, they were doing about 5 to 6 hours of a lot of vigorous-intensity exercise, moderate as well, but they were doing high-intensity interval training, they were doing something called the Norwegian 4x4 protocol.

This is, you're doing 4 minutes of as hard as you can maintain for that 4 minutes, so most people are probably doing 80% of their max heart rate or something like that, or they're not going all out, obviously, and then you recover for 3 minutes, and that's really, you're really going down to let your heart rate go down, and then you do that 4 times. They did that once a week on top of just doing a lot of aerobic, you know, training, and they were able to reverse the aging, the structural changes to their aging heart by 20 years, which is incredible, you know, absolutely incredible. You take a 50-year-old and make their hearts look like a 30-year-old. Like, who wouldn't, who wouldn't sign up for that? You're not going to get that with beta-hydroxybutyrate or lactate.

Rich Roll: And what do we know, again, another like, what do we know or not know about The impact of vigorous exercise versus endurance exercise on moving the needle on cardiovascular health?

Dr. Rhonda Patrick: I mean, they're both good for cardiovascular health, right? You know, like, what I was mentioning was the cardiorespiratory fitness aspect, and the reason I was mentioning that is because almost half the population isn't responding to that if they're just doing the sort of moderate-intensity exercise, where they're doing 70% of their max heart rate for 2.5 hours a week. I like to mention that because it seems that a sizable part of the population really does need a little bit more stress for their body to adapt for whatever reason.

I don't know that that's well understood, but what is understood is that it does occur. And so, you know, I do think, again, you don't want to compare apples to oranges. So, like, a lot of times we'll look at what these endurance athletes are doing, and they're doing a lot of zone 2 exercise, right? But they're doing a lot of it. So, I don't think you can compare someone who's doing over 10 hours a week—

Rich Roll: Oh, no, no.

Dr. Rhonda Patrick: Yeah, I mean, yeah, nobody should really look at that as a benchmark to decide what they're going to do. And, you know, those people, their zone 2 is very unlike the average person's zone 2 because they've been doing it for so many years and they've built this huge base.

Like, the kind of pace that they're able to maintain would be, you know, beyond the threshold of an average person. So, they're putting a— even though they're cardiovascularly they can handle it, they are putting an additional strain on their ligaments and their muscles and things like that. It's very different from the average person.

Rich Roll: But in that conversation, I think it needs to be said that, um, what endurance athletes or, or any, like, you know, elite athlete understands is, is the idea of training on these polarities. And I think the average person spends most of their time somewhere kind of in the middle. They're going A little bit too hard for zone 2.

If they only have a couple hours a week, like zone 2, because they're not that fit, feels like they're not getting anything out of it, and they're not pushing themselves hard enough to get into that threshold vigorous state required to catalyze all of these kind of benefits that, that you're talking about. So a lot of it is like slowing down and then knowing when to speed up and how you create that mix and the construct of how many hours a week you're capable of like devoting to these things.

Dr. Rhonda Patrick: Right, and then don't forget, we have to add in some strength training and resistance training, right? So, I mean, there's a lot, and then you have to work and take care of your family. And so, you know, there's a lot of factors here.

And I think that's where I personally do like the, you know, the, I guess, option to go a little bit harder and not have to spend as much time, and at least be able to make improvements to my cardiovascular system, to, you know, cardiorespiratory fitness, and get things like the lactate. And not to mention, you're doing other, there's other benefits, like you're increasing the number of mitochondria in your muscle, you know, it's called mitochondrial biogenesis, and that's both, you know, doing moderate intensity and high-intensity, you know, exercise does that.

Rich Roll: But over time, isn't zone 2 a more effective way to build mitochondrial density?

Dr. Rhonda Patrick: So, it depends.

If you're comparing, let's say you're comparing someone that is doing a 30-minute zone 2 run versus a 30-minute more vigorous run, then you're going to increase the number of mitochondrial density more by doing the vigorous-intensity. And that is because lactate itself actually signals to your mitochondria to make more mitochondria. And the reason for that is because it's an adaptation. Your body is freaking out. Your body's going, I can't use my mitochondria. I'm not getting oxygen here quick enough to make energy with my mitochondria. Therefore, I need to make more mitochondria to try to adapt so that I can use the mitochondria to make the energy.

Rich Roll: Do you see what I'm saying?

Dr. Rhonda Patrick: Yeah.

So, the high-intensity, so the vigorous-intensity exercise stresses the mitochondria in a way through lactate that's increasing the mitochondrial number. But, you know, zone 2 training can affect mitochondrial size, so it can make mitochondrial— it can increase the mitochondrial size, and so there are differences there, but generally speaking, if you were doing the same volume of training, then a more vigorous exercise would actually improve mitochondrial density more. Now, if you were to then take and do, like, let's say you were going to do an hour-long zone 2 versus, you know, the 30-minute, then maybe you start to get more differences, right? So again, it's like, it all depends on what we're comparing here, apples to oranges. Like, are the same durations the same?

Or— because most of the time, if you're doing zone 2, you're going to have a longer duration anyways, right? Then that's the whole point of doing high-intensity interval training, is it's time efficient, right? So you can get more bang for your buck. Now, there are differences as well, and certainly for people that are endurance athletes, they have to spend more time doing more zone 2. But in no way would I ever say or think it's accurate to say that doing vigorous-intensity exercise is not improving your mitochondrial function or improving mitochondrial number or density, because it absolutely is. It's very, very strongly improving mitochondrial function and mitochondrial density. So, I wouldn't— I wouldn't feel like you're lacking something by, you know, engaging more in high-intensity interval training and not doing enough zone 2 either. So I think there's a little confusion out there with that. So I just wanna clarify that.

Rich Roll: Yeah, yeah.