Transcription
We all want to avoid the cloaked bones of death, holding its scythe, for as long as possible. And it turns out there's two things that you can do that have a massive impact in protecting you from its bony fingers. I know health influencers throw around hyperbolic phrases like "massive" and "incredible" and "effects" and all that stuff, but I'm not exaggerating, as you'll soon see. So let's get into what they are, what the signs show, and what you can do to gain these massive effects. The first habit is ping pong, and the other is pretend smoking Twizzlers. No, no, it's, as you can see from the study, cardiorespiratory fitness and sauna use. But the intriguing thing is how effective they are paired. One is far more powerful than the other, but they both seem to provide additive benefit.
In the study, the researchers quantified the amount of sauna use and cardiorespiratory fitness of over 2,000 participants in their mid-50s. Some had cardiovascular disease, and some didn't. But the researchers assessed these two variables, along with many others that we'll get into shortly, at baseline and then tracked over 26 years how many people died of cardiovascular disease and how many people died, well, in general. They were then able to stratify across low sauna use, high sauna use, low cardiorespiratory fitness, and, would you guess it, high cardiorespiratory fitness, and combinations of the conditions. So low sauna use was two times or less per week, and low cardiorespiratory fitness was under 30 milliliters per kilogram per minute. So that's a VO2 measure if you're familiar.
If we pop open those data, we can see cardiovascular disease caused mortality on the left and all-cause mortality on the right, right? And you can see the corresponding colors related to low and high levels of each condition. FSB isn't the Russian security service, but frequency of sauna baths; and CRF is cardiorespiratory fitness. We can see the time, p, on the horizontal axis and the amount of CVD mortality—that's cardiovascular disease mortality—and overall mortality on the vertical axis. So if the lines go up, that's worse. Clearly, the bluish-purple line and the green line indicate worse results, and those happen to be the lowest in cardiorespiratory fitness, with an improvement with frequent sauna bathing. The green line, however, when cardiorespiratory fitness is high, mortality risk gets crushed into the depths of hell. Okay, I'm actually being a bit dramatic, but clearly it gets crushed into the depths of hell.
The issue with these data, as longtime Physionic viewers will attest, is the fact that these are simple associations. So it doesn't account for any other factors, confounding factors like body weight, socioeconomic status, smoking, high blood pressure, and so on. You get the picture. Fortunately, I did mention the researchers collected a bunch of data on these 2,000 participants, and they did a number of adjustments, controlling for many factors. And they also reanalyzed the data, taking those factors into account. And here are the results. I realized this isn't easy to read, but have no fear, I'll walk you through it, because there's some changes that seem to occur when accounting for these variables.
So on the left side, we clearly see the high and low levels of both key factors that we're interested in and the two outcomes: mortality. Now, up top, we see different models. These correspond to the statistical analyses that account for a variety of factors. So model one, for example, accounts for age only. Model two accounts for age, weight, smoking, blood pressure, cholesterol, and these other factors I'll list on screen. Model three accounts for all the previous factors but also socioeconomic status and C-reactive protein, which is an inflammatory marker. So if we focus on the most adjusted model, model three, we see that the reference is low cardiorespiratory fitness and low sauna bathing frequency. If the risk goes below one, that indicates reduced risk, and we clearly see all the conditions have reduced risk. So if you pull any one lever—improved cardiorespiratory fitness or more sauna bathing—again, mortality risk is reduced across the board. However, there's something important to be said about this, because one clue keeps popping up across the data.
I've been analyzing a good number of studies on sauna and cardiorespiratory fitness, and in so doing, I've put together a variety of ways of figuring out your cardiorespiratory fitness without having to see an exercise physiologist. And I've also put together protocols based on the most effective sauna protocols used in the studies. Both of those guides, along with the extended version of this video, which includes even more fun science, are part of the Physionic Insiders membership. And guess what? That also includes live sessions with this face right here and a private monthly podcast, written research reviews, and more. It's a steal, I tell you. If you want access to all that, just sign up using the Physionic Insiders link in the description. I hope I'll talk to you there.
That clue that I'm referencing is the fact that the majority of the effect seems to be driven by cardiorespiratory fitness. Even the researchers point out that the greatest and most consistent effect on reducing mortality is cardiorespiratory fitness, not sauna. That said, sauna is still beneficial, especially when cardiorespiratory fitness is low, but it just doesn't compare head-to-head, at least on these metrics. Now I should also mention a few more things before we get to the takeaways here. One, this research is limited to a single measure, meaning the cardiorespiratory fitness and sauna and all that jazz was measured at one time point and then never again. So this means that these results are predictive based on a single measurement. Studies that would make measurements over time—say, every, I don't know, five years—would offer us much greater granularity on what matters when it matters and so on. We just don't have that here. Two, this study is only in men. And while I guess that the results would be roughly the same for women, women also have significant, abrupt hormonal changes that affect cardiovascular disease risk. So it's possible that some of these values might shift. Even so, I'd argue it wouldn't be enough of a difference to eliminate the massive benefit, even if, uh, even if that is just educated speculation on my part.
Okay, one more thing that I think really nails the point on how massive these effects are is a metric called NNT: number needed to treat. This statistic tells us how many people we need to treat—in this case, with sauna and good cardiorespiratory fitness—to prevent one death. In this study, they indicate an NNT of four to five. So in the best case, every four people treated prevents one death. That is a monstrous effect. The cloaked figure holding the scythe is going to be out of work with those numbers. Now, how do we use this information? Well, on the cardiorespiratory front, cardiorespiratory fitness is most impacted, without a doubt, by exercise. If you can increase the quality of your muscle—including your heart and lungs, the diaphragm—you will be in that high cardiorespiratory fitness category, essentially. If you aren't exercising, then you're setting yourself up to be in that low camp much faster than someone who moves their body. I'll, I'll have more on that, uh, shortly. As for the sauna, it's pretty simple: increasing sauna use to more than two times per week will do the trick.
So the main points here are that good cardiorespiratory fitness is the greatest protective effect against mortality based on these data, but adding sauna can also provide benefit. I also mentioned I've done a good amount of study analysis on cardiorespiratory fitness, and there's actually another study that indicates that if you can get your cardiorespiratory fitness in a certain range, you can extend your life by a set number of years. I cover that here. Otherwise, there's much more on sauna as well, right here. Thanks for tuning in. [Music]