A short discussion on Heart Rate Variability (aka HRV)

I talk a lot about Heart Rate Variability (HRV) on my social media posts, especially when answering my weekly Q&As on Instagram. But then I get more questions about HRV. So I decided to do this short post to discuss HRV. I emphasize "short" because you can go very deep on this topic. 

Heart Rate vs Heart Rate Variability

A common question I get is "what's the difference between heart rate and heart rate variability?" 

Heart Rate is the number of heartbeats within a time frame, typically a minute

Heart Rate Variability is the time in between the beats and how much it varies. 

Whenever I ask patients if they measure their HRV many will say YES and turn to their apple watch and tell me their HEART RATE. Currently, the apple watch does have a metric for HRV, but you'd have to set that up in your settings to display that. Most times it defaults to Heart Rate. 

So how do you measure it? 

The most convenient and accurate way to measure HRV is to use a chest strap monitor paired with an app.  The most accurate way is to measure the heart directly, but that's not convenient for anyone. 

Chest strap monitor - POLAR

App - ELITE HRV

The next accurate way to measure HRV is by measuring the pulse in the fingers. There are monitors from Elite HRV (CorSense) and also the infamous Oura Ring. 

The least accurate way I've found is by measuring the wrist and arm. The connections and readouts just don't fall into the range of being accurate. 

I'd start with the chest strap monitor and ELITE HRV. Or if you want an all-inclusive package, go with the Oura ring. I personally use both and they correlate well. 

How do you measure HRV and what does it mean? 

You should get a week's worth of measurements and that will form your baseline. I'd recommend taking your reading first thing in the morning. Measurement time should be about 2-3 minutes minimum.

Then I usually use the rule of 10 deviations from that baseline (especially drops) to let me know that I'm going into the "stress zone" 

What? 

Say you take your measurements for a week and it averages out to 40, that would be considered your baseline. Now if one day your reading drops to 30 you know that your body is under a higher than normal stress load or it hasn't fully recovered. 

Without getting too technical, a drop in HRV means that you are stressed out. A rise in HRV typically means you're doing good, in a relaxed/healing state.  

How is this helpful? 

I utilize HRV in two main ways. I let it dictate my training intensity and also when I can splurge on the diet (aka sugar consumption). 

Say my HRV is in the tank, I know that I can't push my body at a high intensity so I would back off on my training regimen. If I had a heavy intense training session on the schedule and my HRV for that day was lower than baseline, I would take it easy or even just chill out. 

Also if HRV is low your ability to consume and metabolize sugar is decreased. But this is usually the time when people turn to binge sugar consumption! 

Ok, so if my HRV is low how do I increase it? 

Many people will ask, "what's a good HRV?" There's nothing really set in stone as of yet, but we do have population averages that can serve as benchmarks. But we still have to adhere to what our own baseline is. 

With that said, whenever I see people's HRV below 25 I know they're in a stressed-out state! 

There are 3 main things we focus on to improve HRV

1. Focused Breathing
2. Improving Aerobic Fitness
3. Decreasing systemic inflammation starting in the gut

I teach all of these in my courses which you can find here (Total Gut Restore & Hormonal Harmony) 

I hope this helps to impart some clarity on this dense topic. 

Studies & References

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5624990/ 

https://www.polar.com/blog/heart-rate-variability-hrv/