Dr. Jay Wiles

I can take that raw EEG and I can filter it and start to get the component rhythms of your brainwave state and how strong they're responding.

Alpha, beta, theta, gamma, delta, and so forth.

We can do the same thing and look at characteristics of your cardiovascular system.

We just call it something different in the HRV world.

It's just three bands that are typically looked at.

It's the very low frequency band, low frequency,

And high frequency.

So when you're breathing at a slow paced rate, so you're doing HRV biofeedback, for instance, or resonance breathing, you start to create these really long sinusoidal low frequency oscillations of your heart rate.

So the peak to trough differences between your heart rate start to change significantly.

So maybe at rest, your heart rate's just going from let's say 60 up to 63, 64, 65, and then back down.

Now we're going from your heart rates at 60, it's going up to 75, 80, 90 even if you have a really strong baroreflex gain, and then it's dropping.

And it's going well below 60 to 55, 50, 40, 45.

So that's low frequency power.

These real...

sinusoidal large-scale changes in the heart rate.

So when we see someone that has a lot of power in the low frequency band, we typically know that they're breathing at a really slow rate, and that's an oscillation that's occurring that's in line, again, with that baroreflex response.

And then high frequency power is what we call the respiratory sinus arrhythmia band.

So at rest, when you're not breathing at a slow pace, most of the power should be in the high frequency band because that's where kind of just the normal breathing oscillation should occur.

So when we look at high frequency power, we know that as someone becomes more attuned to resonance breathing, that number increases because your vagus nerve is what is driving the power there more.

Yeah, and you can kind of bookend it.