Heart Rate Variability (HRV): A Key to Optimal Brain Health

What is Heart Rate Variability (HRV)?

Heart Rate Variability (HRV) refers to the variation in time between consecutive heartbeats. A healthy heart doesn't beat with mechanical regularity. Instead, it shows dynamic adaptability with high variability. To illustrate, heart rate naturally speeds up during inhalation and slows during exhalation. Within this respiratory rhythm, each beat-to-beat interval changes slightly. That variability is called HRV. Interestingly, the medical field long ago believed that a healthy heart beat like a metronome, with consistent, evenly spaced beats. We now understand that greater variability reflects a more resilient and responsive autonomic nervous system and is an important health status biomarker. The diagram below shows an example of HRV.

Blood pressure and heart rate are vital signs measured during a routine physical at the doctors office. Heart Rate Variability, on the other hand is not, though should be. Read on to understand the importance of why HRV should be monitored regularly and why the Empowered Brain Program uses HRV from session to session as a critical quantitative measure.

The importance of HRV as a Biometric

HRV plays a significant role in our level of adaptability – physically, cognitively, emotionally – relating to our level of cognitive and physiological resistance in response to environmental demands.

Lower HRV lowers health expression

Lower HRV is linked to conditions including anxiety, depression and sleeping disorders.¹

Additionally, HRV is an appropriate tool for detection of diabetes, sleep apnea, myocardial infarction, cardiac arrhythmia, hypertension, renal failure, psychiatric disorders and more.²

Our Empowered Brain Program is entirely focused on cognitive decline and dementia care. This 2023 study published in Frontiers of Neuroscience found that abnormal HRV changes are seen in mild cognitive impairments, dementia, mild traumatic brain injury, migraine, COVID-19, stroke, epilepsy, and psychological conditions^.3

At this stage one can see the widespread benefits of effectively addressing low Heart Rate Variability levels. That said, let’s take it a step further…

Higher HRV improves health expression

A systematic review study performed in 2021 found that HRV biofeedback training (improving HRV) showed favorable outcomes and reduction in hypertension and cardiovascular prognosis, inflammatory state, asthma disorders, depression and anxiety, sleep disturbances, cognitive performance and pain.⁴

HRV and Biological Aging

HRV is naturally higher when we are young and declines as a natural result of the aging process. Considering the abovementioned studies and the connections between low HRV and many different intertwined chronic health disorders – the lower your HRV within age group, the higher one’s general risk of all cause mortality independent of other risk factors.^5,6

HRV is not just a stress marker, it is a predictor of survival. 

Biological age, youth is therefore well measured and well indicated with HRV.

The Science Explained: HRV and the Heart-Brain Neuraxis

Heart Rate Variability is a measure for neuro-cardiac function, the connections and regulatory signaling between the brain and the heart.

The diversity of conditions influenced by HRV is due to the role the Autonomic Nervous System plays in heart rate. The sympathetic branch speeds up the heart rate and the parasympathetic branch (Vagal) slows it down. Healthy parasympathetic-vagal function increases the level of variance whereas higher sympathetic function reduces it. This is illustrated in Diagram 1 below. ⁷

How HRV relates to Executive Function, Cognition and Dementia 

The Heart-Brain neuraxis plays a significant role in executive function and cognition. Much of this has to do with the role of inhibitory pathways directed from the prefrontal cortex to the heart as well as the afferent cardiac pathways that return to the brain.⁸

More recent studies address the salience of utilizing HRV as a biomarker for cognitive decline, future cognition and as a therapeutic target for improving cognition.^9,10

As it relates to cognitive decline, dementias and Alzheimer's current studies support the use of HRV as an early diagnostic tool as well as a safe non-invasive and cost effective monitoring tool. The Empowered Brain Program uses HRV monitoring as a valuable quantitative tool with our patients on a daily basis within the 12 month rehabilitative care program.^3,11-14 Not only as a health status measure but as a training tool to improve cognitive and many other functions tangibly.

How to Improve Your HRV For Optimal Health and Cognitive Performance

The quality of HRV can be easily improved with regular aerobic and strength training exercises. Generally speaking, everybody should be actively engaged in several days of both forms of training per week.

• 2-3 days of Zone 2 aerobic exercise like running, swimming or cycling at a moderate pace
• 2-3 days of strength training / resistance exercises

Interestingly, through strategic utilization of High Intensity Interval Training (HIIIT) workouts, it is possible to combine the above for optimal time efficiency.

The Empowered Brain Program is proud to partner with HeartMath® technology, enabling patients to engage in targeted breathing protocols supported by real-time HRV biofeedback. This form of guided meditation integrates both emotional and cognitive focus—making it especially effective for building Heart-Brain Coherence, the alignment of rhythmic wave patterns between heart rate variability and brain function.

Breathing-based meditation—such as Box Breathing—is a simple, effective way to stimulate vagal nerve activity and directly improve Heart Rate Variability (HRV). A classic Box Breathing rhythm follows a 4:4:4:4 ratio: inhale for a count of 4, hold for 4, exhale for 4, and hold again for 4. Practicing this for just 5 minutes daily, especially in the evening, can yield measurable benefits.

You can gradually increase the count (e.g., 5:5:5:5) as your breath control improves. Some individuals may prefer the 6:7:8 pattern—inhale for 6, hold for 7, and exhale for 8—which promotes deep relaxation and is especially helpful before sleep.

Disclaimer: The information presented in this article is for educational purposes only and is based on evidence-informed research. It is not intended to diagnose, treat, cure, or prevent any disease. Always consult your qualified healthcare provider before making changes to your health regimen.