Heart Rate Variability, or HRV, is a metric that measures the amount of time between each heartbeat and the variation in the timings.

Your body is a wonderful, constantly adapting marvel. It does a bunch of stuff that keeps you alive without you even knowing it.

autonomic nervous system

The system that automatically takes care of all crucial housekeeping tasks is called autonomic nervous system. It has two parts to it: the sympathetic nervous system and the parasympathetic nervous system.

The sympathetic nervous system comes to the fore when you’re reacting to a perceived threat.

When your head is down, delivering to a deadline, when you’re exercising moderately to vigorously, and when you perceive something is threatening, it causes you to be afraid. It’s your fight or flight response. It triggers a physiological cascade so that your heart beats faster, your respiratory rate increases, and oxygenated blood is prioritized for your arms and legs. 

The non-prioritized tasks like digesting lunch are put on hold because they’re not needed. When we decide it’s time to stand down, the parasympathetic nervous system comes to the fore.

The immediate repair work within our bodies begins and digestion turns back on. These two systems work interchangeably throughout the day and night. Most of the time, you’re not even aware that it’s happening.

measure with hrv

One way of measuring the interplay is through heart rate variability. Your body is designed to constantly adapt, so that increasing and slowing down your heartbeat, depending on whether you’re fueled by the sympathetic or the parasympathetic nervous system, creates a lot of variability in the timing of your heartbeat.

What’s a good number for HRV?

High HRV scores are a good thing, because it shows that you’re responding to the stimuli of your day by moving in and out of fight or flight, or rest and digest. 

Just like your body, HRV is highly individualized, and it’s influenced by a wide range of factors. There isn’t a good number, per se. But there is a good trend, and that trend is going up over time. 

If you have a low HRV, chances are, you’re only relying on one system, and it’s usually fight or flight.

HRV declines as we get older

It is important to review your HRV trend. Things that can reduce HRV include poor sleep quality, or not enough sleep, overtraining, or even a one off overdoing it at the gym. Your body is designed to deal with all of it. But the trick is to give your body the space to do that. 

A downwards dip in your HRV trend could be a sign that your body is fighting off an underlying illness. Alcohol and a diet low in nutrient-dense foods can also reduce your HRV, as well as being dehydrated.

support your health and well-being with hrv

The first step is awareness. When you first start wearing your device, give it a couple of weeks of consistent measuring so that you know what’s normal for you. Notice the trend.

Use it to stage your workout schedule and recovery sessions and lighter workouts until you’re back to your normal range. If you want to improve your HRV, start playing with things that can increase your HRV, but introduce them one at a time so that you can measure their impact.

The best place to start is with your sleep. It’s not only about a consistent bedtime and wake-up time. Look at the number of hours you’re getting as well. Look at your sleep cycles. You’ll move from alert to REM to deep sleep in around 19 minutes, and these cycles will repeat through the night.

If you’re waking up tired, check if you’re getting enough deep sleep. Play with increasing your fitness, and then more, and build in more focused recovery sessions than you’re used to.

Heart rate variability is a wonderful tool for noticing how the way you’re living is supporting or detracting from any work for your body.

You’ll be amazed at how only one thing can tip the balance, can boost your immune system, can improve your mood, and can help you be more resilient.