Dr. Rhonda Patrick: Yeah, maybe we should, that's a good segue into some of the high-intensity interval training protocols that are evidence-based in terms of improving cardiorespiratory fitness, for example. And a lot of these protocols are also, also improve other parameters which we're gonna get into as well, like mitochondrial density as well as other metabolic benefits. But the Norwegian 4x4, so this is one of the most studied protocols. It's a very well-studied protocol where Dr. Benjamin Levine talked about it. Dr. Martin Gibala talked about it. People are doing four different intervals. So they're doing for four minutes, they are exercising typically on a stationary bike, perhaps a rowing machine. You could do it on a treadmill as well.

But a lot, a lot of the, the protocols were on the, on a bike. And you're doing, for the 4-minute interval, you're, you're going at an intensity that you can maintain for that entire 4 minutes, that's pretty hard. So it's, it's pretty, pretty much a sustainable hard intensity for 4 minutes. It's obviously not gonna be maximal, but you're going as hard as you can for, and as hard as you can sustain for that 4 minutes. And then you follow that by a 3-minute recovery period, which is very light, right? You want your heart rate to come down, you wanna clear your lactate, and then you go back into the 4-minute interval. So that's a 4x4, you're doing it 4 times. That's a very good protocol to improve cardiorespiratory fitness.

There's a variety of other protocols out there Dr. Martin Gibala mentioned. So there's the 1 minute on, 1 minute off, and you do that 10 times so that the 10-minute workout, well, it's actually 20 minutes, but 10 minutes of more high-intensity training where again, for that entire minute, you're going as hard as you can sustain for that minute, right? It's not gonna be all out, but it's as, as much as, as hard as you can go and sustain that for a minute. And then you rest and recover for a minute at very, very low intensity exercise. And then there's things like even Tabatas. So Tabata would be a 20-second on, 10-second off. You do that 8 times. The 20 seconds, you're really going as hard as you can.

'Cause I mean, 20 seconds is, it's not long, although it seems long when you're going as hard as you can. It actually seems quite long. And the recovery intervals seem too short.

Brady Holmer: They're very— the hard portions seem longer than 20 and the recovery is like over before you know it.

Dr. Rhonda Patrick: Exactly.

Brady Holmer: And there's a variety of other protocols out there as well. But you, we were talking a lot about even just adding, adding a little like higher intensity workout at the end of a run. Do you, do the intervals necessarily have to be 85% of your, your max heart rate? I think, I think for most people it probably, you know, doesn't matter. You shouldn't focus on heart rate.

It's just if you're going hard and your heart rate is elevated above the moderate intensity. You could probably call that high-intensity interval training and you use that to, to say that was my one HIIT session per week. I think, again, I, I mean, heart rate training, I'm not sure how many people actually use it. I know in any study that you use, an exercise physiology study, they'll have measures of heart rate because yeah, you have physiologists on the side measuring your heart rate during exercise. But I mean, I can't tell you the last time I really looked at my heart rate or what percent of my heart rate I was at during exercise. I'm typically just basing it off of RPE and I'm looking at my heart rate after the fact.

So I think that you can pick an interval workout if you wanna do the 4x4, if you wanna do the 10x1, or if you wanna do Tabata. For one, looking at your heart rate the entire time is gonna be distracting, you know, focus on the workout. So I think going at a hard intensity, like you said, an intensity that you think seems sustainable for 4 minutes and, and doing that. I mean, once you get more familiar with the exercise, you may then be able to know that, oh, if I'm going at, you know, however many watts, maybe 120 watts, and this is kind of 85% of my maximum heart rate, you can use that to kind of guide your training. But in general, I mean, again, I think most people aren't going to be looking at their heart rate the entire time.

So we're talking about what your heart rate should be at, but it's just, just go at a hard intensity. And for most people, that's going to be enough to get the benefits of, of high-intensity interval training, which I think is important because I, a lot of the time we get caught up in, oh, what's my heart rate? And if you're going hard, you know whether you're going hard or not. And that can be fine, I think, for most people to train.

Dr. Rhonda Patrick: Right. And again, going back to what we were talking about earlier and what Dr. Benjamin Levine and Dr. Martin Gibala were mentioning about just mixing it up and, and giving that little extra stressor so that you get those adaptations, right? And you don't, you don't wanna keep doing the same thing.

So sometimes even just doing something a little bit harder in your, you know, normal sort of low to moderate intensity workout is beneficial, right?

Brady Holmer: Definitely. And I think, you know, with, with the training, I think there are some people who like to do, I wanna just do the Norwegian 4x4 every week. It's easy. I know what to do. I'm kind of familiar with it. But I think to avoid, not only avoid kind of like stagnation or maybe just get, getting bored of like the workout, but to stress your system in different ways. We just mentioned 3 protocols. Obviously those aren't the only protocols. They're not necessarily the best, but just do different lengths of intervals every week. And I think that can be fun. You know, there's something that I try to do in my own training.

So maybe somebody picks the 4x4. This week you're gonna do 4x4, next week you're doing 10x1, the next week you do a Tabata. So then you have 3 different lengths. You know, you're doing the 4 minutes, which seem particularly good for improving like VO2 max, the 2- to 4-minute range for intervals. You're doing the 10x1 again, which is, you know, 1 minute long. And then you're doing the 20 seconds, which is your sprint interval training as maybe Dr. Martin Gibala might refer to it. So, mixing those things up I think can not only be enjoyable, but then you're hitting really all the body's energetic systems, which, which can be fun as well.

Dr. Rhonda Patrick: Yeah, for sure. Mixing it up, I, that's something I do as well.

Although I do have wonderful coaches that work with me and they're very great at mixing up my routine and it's very nice. But, if, if it's just me left to my own devices, I usually get on my Peloton and I'll do a Tabata and it's the same, almost the same exact class that I have been doing for years. But, you know, sometimes we're just creatures of habit, you know, and it's easy to kind of go back to the thing that you know.