Why keep an eye on HRV

HRV, or heart rate variability, offers a unique insight into the time gaps between heartbeats, measured in milliseconds. It serves as a gauge for the autonomic nervous system (ANS), governing involuntary bodily functions such as heart rate, blood pressure, and breathing.

The ANS consists of two opposing branches: the sympathetic, triggering the "fight or flight" response during stress, and the parasympathetic, orchestrating the "rest and digest" response during relaxation. HRV captures the intricate interplay between these branches, reflecting their optimal balance. When both branches give contrasting signals to the heart—parasympathetic signaling for a slower heartbeat while sympathetic signals for a faster one—it indicates a harmonious and well-regulated nervous system.

In essence, HRV is a dynamic measure showcasing the ongoing dialogue between these two systems.

HRV as a health indicator

A healthy HRV not only signals better fitness but also resilience to stress. Higher HRV values reflect the body's active engagement with both branches of the autonomic nervous system, showcasing responsiveness to feedback and optimal performance readiness.

However, HRV is a sensitive metric, with fluctuations occurring throughout the day. Additionally, individual variations contribute to diverse HRV readings, with factors like age, gender, and athletic ability. Older individuals and women tend to display lower HRVs.

When it comes to HRV monitoring, emphasizing trends within your own readings proves more insightful than direct comparisons with others. Your HRV journey provides valuable insights into your body's unique patterns and readiness to perform at its peak. By focusing on your personal HRV trends, you gain a deeper understanding of your body's typical responses and enhance your ability to optimize performance whenever necessary.

Read about: Biofeedback Technology: Understanding Your Body's Stress Signals


Despite all the possible variations, a normal HRV score generally falls between 40 to 60 (millisecond variation between heartbeats). A very fit and healthy person might have an HRV as high as 70 to 100.

A low HRV value serves as a red flag, indicating potential vulnerabilities in our cardiovascular and respiratory systems. A low HRV is associated with increased stress susceptibility, cardiovascular issues, and weakened immune function.

Several factors can contribute to low HRV, ranging from chronic stress, inadequate sleep, and sedentary lifestyles to underlying medical conditions. The modern whirlwind of constant stressors, coupled with poor lifestyle choices, often causes damage to our bodies that leads to lower HRV. Recognizing these contributors is the first step in reclaiming control over our health.


Decoding symptoms

Since HRV is a complex metric that is tied to many health parameters, some of the most common symptoms associated with low HRV present as complex, multifaceted health issues. Here is what you should watch out for as you start monitoring your HRV in a quest for improved health and well-being:

1. Fatigue

Spot it: Lingering tiredness despite adequate rest, difficulty concentrating, a lack of motivation, heightened sensitivity to stress, and muscle weakness.

Meaning: Low HRV may signify an impaired ability to recover from stressors. Scientifically, a reduced HRV reflects an imbalance in the autonomic nervous system, particularly a dominance of the sympathetic branch over the parasympathetic. This imbalance hampers the body's capacity to efficiently switch between the rest and active states, leading to persistent fatigue, heightened sensitivity to stress, and muscle weakness. Low HRV can even predict burnout!

Also Read; Does Your Heart Rate Increase When Sick?

2. Autonomic Dysfunction

Spot it: Irregular heartbeats, dizziness, difficulty regulating body temperature, digestive issues, reduced exercise capacity, and changes in skin color.

Meaning: A malfunction in the autonomic nervous system, as mirrored by HRV, can manifest in autonomic dysfunction. The ANS regulates involuntary bodily functions, such as heart rate, blood pressure, and body temperature. Reduced HRV implies a dysregulation in this finely tuned system, contributing to symptoms like irregular heartbeats, dizziness, difficulty maintaining a consistent body temperature, digestive issues, reduced exercise capacity, and changes in skin color.

3. Anxiety and Depression

Spot it: Persistent feelings of worry or sadness, irritability, changes in sleep patterns (insomnia or hypersomnia), social withdrawal, decreased cognitive performance, and changes in appetite.

Meaning: Low HRV is intricately linked to compromised emotional resilience, creating a fertile ground for anxiety and depression. Scientifically, a lower HRV indicates an overactive sympathetic nervous system and an underactive parasympathetic nervous system. This imbalance disrupts the delicate dance between stress and relaxation responses, contributing to heightened emotional distress, persistent negative emotions, social withdrawal, decreased cognitive performance, and even changes in appetite.

While a temporarily low HRV is not a big deal and a single reading shouldn’t be a cause for concern, consistently low scores coupled with one of the symptoms described above, should be seen as a call to action. Your body is signaling a need for a lifestyle change and you owe it (and yourself) that much.

Consider incorporating tools like Oxa's breathing exercise device into your routine to improve HRV and overall well-being.


Q: What does low HRV indicate about my health?

A: Low HRV may indicate an imbalance in the autonomic nervous system, suggesting increased stress susceptibility, potential cardiovascular issues, impaired recovery, and weakened immune function.

Q: What is a healthy HRV range, and when is it considered low?

A: A healthy HRV typically ranges between 50-100 milliseconds. Consistently falling below this range may be considered low. Monitoring trends over time is key, as daily metrics can naturally vary. Note, also, that average HRV numbers decline exponentially with age.

Q: Is low HRV reversible?

A: In many cases, adopting lifestyle changes, stress management techniques, controlled breathing practices, and regular exercise can help improve HRV over time.

Serge Weydert
May 28, 2024

Ph.D., is Co-Founder, Scientific Lead and Board Member at Oxa Life. As a neuroscientist and electrical engineer by training, Serge is committed to health innovation. His philosophy centers around empowering people by demystifying health data and restoring control over personal health through actionable insights.

Ready to begin?

Get the Oxa Sensor and your choice of garment - lounge-wear shirt, bra, or adjustable chest strap. Your purchase includes access to the Oxa app which gives personalized data summaries and insights, as well as access to breathing exercises to teach you how to harness the power of your own breath.