Heart Rate Variability (HRV) is a common data point that many biofeedback and wellness wearables such as Hanu are using to help people get a deeper look into their body’s level of physical fitness, resilience, and behavioral flexibility. In this guide, we will be helping you to understand better how to interpret your HRV readings while also laying out average heart rate variability trends based on age and gender.
What is Heart Rate Variability (HRV)
Heart Rate Variability is a useful yet often misunderstood statistic. HRV is the variation of time intervals between heartbeats. In other words, it is the variability of time between each heartbeat. A primal part of the nervous system, known as the autonomic nervous system, controls this variation.
As the name suggests, this part of the nervous system works without conscious control to regulate processes, including your heart rate, blood pressure, breathing, digestion, and other vital tasks.
This unique physiologic phenomenon was first discovered back in the 1800s. Research led by Karl Ludwig found an increase in heart rate upon inhaling and a decrease upon exhaling in test subjects. This finding told researchers that the time between heartbeats was not constant and must be variable.
In recent times, HRV has become a big focus in the health and wellness community due to the increased depth these readings can provide compared to the commonly used beats per minute (BPM) heart rate measurement. The variation observed using HRV allows us to get a clear picture of the body’s ability to prime itself to either brace for action or calm itself and prepare for rest.
In other words, it allows you to get an idea of your body’s ability to tolerate stress – which is a critical measure for understanding your body’s ability to adapt to its environment and perform at a high level. Studies have shown that HRV can help us look at the underlying effects of stress, meditation, and exercise and can also be an early predictor of heart problems.
Now that we understand the efficacy of Heart Rate Variability readings, what is the leading cause of this variability?
The main inputs from the body that trigger these phenomena come from the two divisions of the autonomic nervous system we mentioned – the sympathetic and parasympathetic nervous systems (SNS & PNS). These two nervous systems work in tandem to prepare us to act or divert energy to recovery.
The sympathetic nervous system reacts when it is time to escape from a predator, and the parasympathetic nervous system kicks into gear when it is time to relax or digest a large meal. Think of it like this:
Sympathetic (SNS) = Fight or Flight
Parasympathetic (PNS) = Rest and Digest
To grasp the basics and importance of HRV, it helps to understand the autonomic nervous system and the difference between these two nervous system responses. Here is an example of the different systems involved in these two stress responses (see right).
As we mentioned, HRV readings are essential because they show us how the
body reacts to stressors. Insufficient parasympathetic flow and output (reduced variability) can result in difficulties reaching restful and relaxed states post-stress. At the same time, extended autonomic activity can accumulate as cardiovascular disease risks due to stress and an overly-stimulated sympathetic (fight or flight) response.
Heart Rate Variability by Age and Gender
Another critical aspect of HRV readings is that no specific set of HRV scores based on age and gender tell you if you are “healthy” or not. In reality, HRV levels are a metric that can differ significantly from person to person. Therefore, there isn’t a clear answer for what is a good HRV by age or gender.
For example, athletes and active individuals typically have higher heart rate variability. Still, highly fit and healthy individuals will demonstrate heart rate variability levels that may be below average for their demographic – regardless of factors such as age and gender. Does this indicate that they are “less healthy,” “more stressed,” or “more compromised?”
The answer is no.
It is crucial to analyze overall trends in data. HRV levels can fluctuate from day to day and from person to person. Here are some examples of the average trends found among publicly available HRV data from the World Heart Federation:
- HRV ranges tend to decrease with age
- Males have slightly higher variability than females
- Elite athletes often have a much higher HRV score
- Gender dependencies disappear after age 55
While these points are valid, the study linked above tells us that the actual role aging has on heart rate variability is still unclear. It is more likely that HRV is an indicator of how well your autonomic nervous system is working or how well your body can react to stressors and bring the body back to a healthy center.
What is a Good Heart Rate Variability?
When you begin to collect some personal HRV data, the most important thing to remember is that you are unique! There isn’t a standard set of HRV values based on fitness. The only reference you should be comparing your scores with is your historical HRV data.
Due to the reasons mentioned above, there is no point in comparing your data with average scores. The best way to get the most out of your HRV data is to analyze your trends over time – both short and long-term. A “good” heart rate variability score is studied over the long term rather than daily. Deviations from your baseline are a warning sign. As our friend Marco Altini always says, a normal HRV is better.
The heart rate variability data that your wearable gives you depends on various factors, including your genetics, lifestyle choices, level of physical fitness, stress, age, gender, and environment. When analyzing your average HRV data, we encourage you to pay attention to the overall trends that the data displays over time rather than how well you fit into the “normal ranges” of data.
You will notice that your variability increases as you improve your lifestyle and get into better shape. This increase indicates that your heart health and overall wellness are improving. If you notice that your HRV decreases, you are putting too much stress and pressure on yourself and may need to ease up and find more balance in your lifestyle.
Want to get real-time access to your HRV data? Hanu can help you track your HRV and give you actionable insights based on your daily readings. Dig deeper into your heart health and better understand your baseline with Hanu.