Dr. Jay Wiles

So when we look at it across a seven-day window, is it varying significantly, indicating that it's having a hard time adjusting because it's going up and down and up and down, maybe due to stress?

overtraining, overreaching, or is it nice and stable, indicating that the nervous system is always rebounding, it's always doing what it should do?

So I know that's a long-winded way of saying, is high good, low bad?

The answer is yes and no, but mostly no.

There are a lot of different factors that come into play here.

So you have to think about a couple of things.

I think the biggest thing are what are the non-modifiable factors that influence heart rate variability?

And then what are the modifiable factors?

Because I think that we place a lot of pressure in a day and age where there's like so much motivation.

I guess, biometric hypervigilance.

We place a lot of pressure on ourselves to have certain metrics meet whatever our standards are.

Typically, they're pretty arbitrary standards because people are just like, again, I saw somebody who had a 200 millisecond HRV.

I probably should have that because they're a pro athlete.

We're comparing apples and oranges here.

We're using the same metric, but we're comparing two different physiological presentations.

So let's talk then about, first, non-modifiable influencers, because I think that that's the one that people need to hear more than anything.

The first one's age.

Age is one of the primary non-modifiable factors that we see within the literature.

If you go and you look at the literature that compares normative values across longitudinal time in these studies, we see that there is a distinct negative slope there.

And one of the things that's happening is that generally around ages 40 to 50 or so, or even like in the mid 30s, we start to see a pretty steep decline in baseline heart rate variability.