Dr. Andy Galpin

Heart rate variability is exactly what it sounds like. It is the variation in your heart rate. Let me use an example. Let's say your resting heart rate is 60 beats per minute. You would then assume that since there's 60 seconds in one minute, that your heart is then beating, in this example, every second on the second.

And then if you sped your heart rate up to 670 or 80 or 90 or 100 beats per minute, you would simply shorten the time between each heartbeat. But that the time between each heartbeat would be the same. It'd be one second or half a second or three quarters of a second or whatever the case is. Well, in that particular case, there's no variation in your heart rate. That's not actually what happens.

And then if you sped your heart rate up to 670 or 80 or 90 or 100 beats per minute, you would simply shorten the time between each heartbeat. But that the time between each heartbeat would be the same. It'd be one second or half a second or three quarters of a second or whatever the case is. Well, in that particular case, there's no variation in your heart rate. That's not actually what happens.

If your heart rate is 60 beats per minute, What's going to happen naturally is maybe it beats at 1.1 second, and the next beat comes at 1.2 seconds later, and the next beat after that comes 0.9 seconds later, and then it comes at 0.8, and then it goes to 1.3. And so there's variations. At the end of the 60 seconds, you'll still have done 60 beats, but it won't be a metronome.

If your heart rate is 60 beats per minute, What's going to happen naturally is maybe it beats at 1.1 second, and the next beat comes at 1.2 seconds later, and the next beat after that comes 0.9 seconds later, and then it comes at 0.8, and then it goes to 1.3. And so there's variations. At the end of the 60 seconds, you'll still have done 60 beats, but it won't be a metronome.

It doesn't happen every second on the second. How variable that is, is the marker we're talking about. It's a little bit counterintuitive, but the more variation, the more parasympathetic you are. So the more variation in your heart rate, the more down-regulated. If it becomes like a metronome, every second on the second, it's dialed in, that means you're in sympathetic drive.

It doesn't happen every second on the second. How variable that is, is the marker we're talking about. It's a little bit counterintuitive, but the more variation, the more parasympathetic you are. So the more variation in your heart rate, the more down-regulated. If it becomes like a metronome, every second on the second, it's dialed in, that means you're in sympathetic drive.

Now, as I said, parasympathetic and sympathetic aren't on-off switches. They toggle back and forth. So HRV is just telling us kind of where at on that entire spectrum we are. Generally, on average here, we want to spend more time in parasympathetic, meaning a higher HRV, and less time in sympathetic. Most people struggle with spending too much time in sympathetic and therefore have a low HRV.

Now, as I said, parasympathetic and sympathetic aren't on-off switches. They toggle back and forth. So HRV is just telling us kind of where at on that entire spectrum we are. Generally, on average here, we want to spend more time in parasympathetic, meaning a higher HRV, and less time in sympathetic. Most people struggle with spending too much time in sympathetic and therefore have a low HRV.

Now, you can have the opposite problem, and we have seen that. I've coached people through that, where their HRV is extraordinarily high and they're lethargic with no energy, no motivation, and so on and so forth. But that's way more rare. Generally, I would probably say 95 times out of 100, it's the opposite.

Now, you can have the opposite problem, and we have seen that. I've coached people through that, where their HRV is extraordinarily high and they're lethargic with no energy, no motivation, and so on and so forth. But that's way more rare. Generally, I would probably say 95 times out of 100, it's the opposite.

We're getting people out of so much time in sympathetic drive and more in parasympathetic. A million explanations for this, but just as a practical example, you can imagine going from a A high stress job, sitting in traffic, even if it's not a high stress job, but it's a job.

We're getting people out of so much time in sympathetic drive and more in parasympathetic. A million explanations for this, but just as a practical example, you can imagine going from a A high stress job, sitting in traffic, even if it's not a high stress job, but it's a job.

You're around people, you're performing, you're in traffic, you're listening to podcasts, you're coming home, you're watching TV, and it's just sensory input all the time that requires your attention and reaction. If you're managing children, if you're managing other stuff, and there's just not enough quiet time that used to be around us.

You're around people, you're performing, you're in traffic, you're listening to podcasts, you're coming home, you're watching TV, and it's just sensory input all the time that requires your attention and reaction. If you're managing children, if you're managing other stuff, and there's just not enough quiet time that used to be around us.

Plenty of other reasons to explain it, but that's a good way to kind of understand the idea here of why most people are probably in sympathetic drive. If you want to say that that means we're in a more stressed life than we used to be, I don't know. I'll leave that up to you.

Plenty of other reasons to explain it, but that's a good way to kind of understand the idea here of why most people are probably in sympathetic drive. If you want to say that that means we're in a more stressed life than we used to be, I don't know. I'll leave that up to you.

But just from a practical perspective, we have way more arousal coming in way more frequently than we probably had for most of our experience as a human species. That's what HRV is, it's that variation, and that's what it tells us. It is a snapshot into the autonomic nervous system, specifically parasympathetic and sympathetic drive. It is only one metric. It is not perfect.

But just from a practical perspective, we have way more arousal coming in way more frequently than we probably had for most of our experience as a human species. That's what HRV is, it's that variation, and that's what it tells us. It is a snapshot into the autonomic nervous system, specifically parasympathetic and sympathetic drive. It is only one metric. It is not perfect.

There's not a single metric I will show you today that is perfect, but it does have a lot of research behind it. So that's roughly what HRV is. It is, at our best guess, 50% genetic and 50% lifestyle. Admittedly, I am not thoroughly impressed with that research.