You're familiar with terms like pulse and blood pressure, but heart rate variability doesn't ring a bell? Don't panic, today we'll explain the concept for you and why knowing more about your heart rate variability is beneficial for great workout results. It also provides valuable insights into your overall state of health and your stress level.
What exactly is heart rate variability?
Intuitively, most people probably think at first that it's good if the heart beats evenly – completely in rhythm. Let's assume you have a resting heart rate of 60, so you probably think your heart ideally beats exactly once every second. And after exactly another second. And again. But that's not the case: The interval between heartbeats is never exactly the same. Instead, it always varies slightly. Sometimes the next heartbeat occurs after 1.1 seconds, sometimes after 0.9 seconds. The intervals between individual beats are never exactly equal. And it's precisely these fluctuations between individual heartbeats that are expressed by heart rate variability, or HRV for short. Thus, HRV refers to the time variations between two heartbeats.
High heart rate variability means good fitness and health
We all know that our heart beats slower at rest and faster under exertion such as exercise or in stressful situations. But now it's clear that our heart never beats as evenly as a metronome, for example. If a high HRV is measured, it means in a positive sense that your body, especially your heart, adapts quickly and efficiently at any given moment to internal and external information – virtually within a single heartbeat. In a matter of seconds, your heart adapts to the new situation and to signals coming internally from the nervous system, your cells, your breathing, etc., as well as those coming from the outside world. And the faster and higher this variance is, the smarter your heart can react appropriately to changes. Which is a good thing. Exciting fact: The more relaxed and calm you are, the more variably your heart beats. And the more stressed and unbalanced your body is, the more evenly your heart beats, meaning your HRV decreases. Crazy, right? So a high heart rate variability indicates that your body has recovered well after a workout session and you are ready for your next workout.
What a low HRV says about your fitness level and stress level
A low heart rate variability gives you indications of how your body is currently doing. Normally, a high HRV tells you that everything is okay with your heart – it is able to react immediately to all internal and external influences within a very short time and adapt to the new situation. After a workout, heart rate variability should slowly rise again. If it does, you are ready for the next session. However, if it stays low, it tells you that your body is still under stress and you may have trained too hard. Or that other stress factors are preventing your HRV from recovering.
Which factors lead to a low HRV and which ones increase it
Let's briefly remind ourselves: A high heart rate variability indicates that your heart is capable of reacting super-fast within milliseconds to even the smallest change in information inside and outside your body. Your body can, so to speak, shift up or down a gear with great flexibility, depending on what the situation demands. By the way, you can easily see this on any ECG (electrocardiogram). The distance between the small spikes, the so-called R-waves, is never exactly identical, but ideally varies slightly.
The lower this variability, the more it reveals that your body is (still) in a stressful situation.
The following factors promote stress and should therefore be avoided:
-
Ongoing mental stress
-
Unbalanced and unhealthy diet
-
Too little sleep
-
Alcohol and nicotine consumption
-
Too much exercise/overtraining
So it should also be clear how to achieve high heart rate variability again. Namely, by eliminating the above factors:
-
Stress reduction through relaxation phases
-
Balanced, healthy diet
-
Sufficient sleep
-
Regular exercise
-
Avoid alcohol and nicotine
-
Avoid or reduce excess weight
-
Balanced workout with enough recovery phases in between
Measuring heart rate variability correctly
In the past, you went to the doctor to get an ECG to learn something about your heart rate variability. Nowadays, thanks to modern apps and devices such as wearables (small fitness computers you usually wear as a wristband or strap), this is no longer necessary at all. Many apps today also show you your heart rate variability values. Important note: you cannot compare your own values with those of other people, because everyone has a different HRV. The smartest approach is to measure your values over a longer period first and draw conclusions about your state of health and fitness based on the changes. After a demanding and exhausting workout, your HRV will initially be quite low for a day or two. But then it should slowly recover and rise again. That's how you know your body is ready for a new workout session. If it remains at a low level for longer, it is a sign of training too hard, that you haven't recovered enough yet, or of other stress factors. High-quality sports watches from well-known manufacturers help you keep an eye on your heart rate variability in order to train as effectively as possible.
