Dr. Andy Galpin

So you're talking $100, $115 or something like that. You could have yourself a nice HIV tool. One more time to be really clear. If we are concerned about HIV, we're going to go with one of those devices. We're going to measure it directly from the chest. We're not going to measure it from the finger or the wrist or anywhere else unless we absolutely have to.

Now, it's been a long time since we talked about this, but earlier I brought up respiratory rate. And I'm going to come back to it now. There's not as much research here, but it is growing. And what's clear about respiratory rate is the information you get from it is different than what you get from heart rate variability. And so ideally, you're going to pay attention to both of these.

Now, it's been a long time since we talked about this, but earlier I brought up respiratory rate. And I'm going to come back to it now. There's not as much research here, but it is growing. And what's clear about respiratory rate is the information you get from it is different than what you get from heart rate variability. And so ideally, you're going to pay attention to both of these.

Respiratory rate, like HRV... It is a non-specific, but highly sensitive measure of your nervous system. In other words, if your HRV is up or down, or your respiratory rate is up or down, something's happening. It's very sensitive to changes. You will see changes within a day. As I just described, you can change these things within minutes or seconds.

Respiratory rate, like HRV... It is a non-specific, but highly sensitive measure of your nervous system. In other words, if your HRV is up or down, or your respiratory rate is up or down, something's happening. It's very sensitive to changes. You will see changes within a day. As I just described, you can change these things within minutes or seconds.

If you see changes over a couple of days, it means something, but they're non-specific. They're not telling you, oh, this was your nutrition, or, oh, this is your mental stress, or, oh, this is hydration or bad sleep. You don't know what's happening. It's simply telling you something about the overall allostatic load, the total stress of the environment.

If you see changes over a couple of days, it means something, but they're non-specific. They're not telling you, oh, this was your nutrition, or, oh, this is your mental stress, or, oh, this is hydration or bad sleep. You don't know what's happening. It's simply telling you something about the overall allostatic load, the total stress of the environment.

So then you gotta go work to figure out what's happening there, but they are both highly relevant. Why I like respiratory rate arguably the most here is because I have personally, and now I'm walking away from the research here, I can't show this scientifically yet, But I have found it personally to be more sensitive. It'll show up fast.

So then you gotta go work to figure out what's happening there, but they are both highly relevant. Why I like respiratory rate arguably the most here is because I have personally, and now I'm walking away from the research here, I can't show this scientifically yet, But I have found it personally to be more sensitive. It'll show up fast.

Oftentimes, not always, but oftentimes in my personal experience, you'll see changes in respiratory rate before you'll see them in HRV. You know, anything that matters, but not always. And so we really pay high attention to both.

Oftentimes, not always, but oftentimes in my personal experience, you'll see changes in respiratory rate before you'll see them in HRV. You know, anything that matters, but not always. And so we really pay high attention to both.

There's a really wonderful article in a technology journal actually called Sensors published a couple of years ago by a scientist that I just love in this field, Andre Nicolo, called The Importance of Respiratory Rate Monitoring from Healthcare to Sport and Exercise. And in that paper, they walk you through a ton of the research, what's going on here, the fact that it is a critical vital sign

There's a really wonderful article in a technology journal actually called Sensors published a couple of years ago by a scientist that I just love in this field, Andre Nicolo, called The Importance of Respiratory Rate Monitoring from Healthcare to Sport and Exercise. And in that paper, they walk you through a ton of the research, what's going on here, the fact that it is a critical vital sign

It has been associated with everything from cardiac events and pneumonia to heat exposure and cold and exercise, emotional stress, cognitive load, and so on and so forth. You can go read about more of the details of respiratory rate there. I've thrown this out a couple of times at the beginning, but I wanted to finally tie a bow on this as well. What does this have to do with CO2 tolerance?

It has been associated with everything from cardiac events and pneumonia to heat exposure and cold and exercise, emotional stress, cognitive load, and so on and so forth. You can go read about more of the details of respiratory rate there. I've thrown this out a couple of times at the beginning, but I wanted to finally tie a bow on this as well. What does this have to do with CO2 tolerance?

If you're not familiar with that, This is a similar metric. So when we're looking at respiratory rate and we're looking at resting heart rate and HRV, we also like to pay attention to CO2 tolerance. This is a different way of examining the state of your nervous system.

If you're not familiar with that, This is a similar metric. So when we're looking at respiratory rate and we're looking at resting heart rate and HRV, we also like to pay attention to CO2 tolerance. This is a different way of examining the state of your nervous system.

Specifically, the way that we have defined CO2 tolerance, this is developed, or rather was brought to me by a gentleman named Brian McKenzie. I don't know who created it initially, but Brian is the one who taught me about it.

Specifically, the way that we have defined CO2 tolerance, this is developed, or rather was brought to me by a gentleman named Brian McKenzie. I don't know who created it initially, but Brian is the one who taught me about it.

And the way that this works is it's effectively like a little bit of a breath hold test where you exhale continuously and you can see how long that you can continually exhale some small amount of air. It's a maximal effort test. In the show notes, we'll put a direct link to a video Brian has made that shows you how to go through the CO2 tolerance test. And I like it. We've used it a bunch.