HRV – Should Your GP Be Monitoring This?
Wearables are everywhere and they are growing in popularity. Many patients come in wearing them. Some proudly show me their connected apps. Others are content with using them as expensive pedometers.
Although they have their downsides, particularly amongst the more neurotic clients on the spectrum, they will have an increasing role in modern healthcare.
A measurement that many are not aware of is heart rate variability.
Our heart needs to be able to adjust the rate it beats at in response to our environment. There are multiple systems at play which include the autonomic nervous system, cardiovascular system, the endocrine system, the respiratory system and baroreceptors (pressure receptors) and chemoreceptors in the circulatory system.
This ability to quickly adapt allows us to escape danger or when we still lived on the Savanna, we were able to quickly run away from the proverbial lion. But we clearly don't live in that setting any longer, so why should it matter?
Research has repeatedly shown that having a decreased heart rate variability is a measure of current or future health problems. The body is less resilient at handling challenges. This may be an illness, an accident, or even a stressful argument.
If HRV is optimal, then self-regulatory capacity is better and attention and emotional processing is improved.
If there is a higher resting heart rate, there is a decreased chance of having an optimal HRV because the time between beats is so short. This often occurs in diabetes, high blood pressure, asthma, anxiety or depression.
So how can I improve it doc?
Focus on the body and focus on the mind. Both need to be working well to optimize HRV. Exercise is the most effective intervention, but emotional health and mind play a significant role too.
(1) Alcohol: It significantly impacts HRV negatively, particularly when consumed later on in the day. Consider stopping it completely, or drinking earlier in the day if going to drink.
(2) Exercise training: Higher intensities and increased frequencies see the most benefit.
(3) Biofeedback training: This upregulates the vagus nerve and by breathing at 6 breaths per minute combined with mental training improves HRV very effectively.
(4) Progressive muscle relaxation: This technique has been shown to improve HRV and autonomic balance.
(5) Meditation and mindfulness: Evidence shows these practices can enhance HRV, particularly during practice sessions, though effects on resting HRV are more variable.
(6) Sleeping adequately is vital: Poor sleep quality and sleep deprivation are associated with reduced HRV and impaired cardiac autonomic function.
Emerging evidence
(1) The gut-brain axis has become well established. Through the short chain fatty acids that are produced by the microbiome, these have plausible positive mechanistic effects on improving heart rate variability. Read that as increasing all fiber and plant foods in the diet!
(2) Social connections are vitally important. We are social animals and living in isolation affects HRV negatively.
(3) Omega-3, B vitamins, probiotics, polyphenols and the Mediterranean dietary pattern have been linked to improved HRV.
(4) Weight loss if there is metabolic dysfunction or overweight or obesity.
Additional factors that worsen HRV:
(1) Nicotine in any form
(2) Lack of sleep
(3) Alcohol
(4) High saturated and trans-fat intake
(5) High glycemic carbohydrates
(6) Caffeine
(7) High mental stress
(8) Infections
So what should my HRV be?
This depends on age and sex. It also depends how it was calculated and measured.
There are a few ways of calculating this and the ranges depend on whether measuring: the RMSSD "root mean square of successive differences" or the SDNN "standard deviation of normal to normal intervals." It also matters whether using a calculation from 24 hours or 5 minutes.
Most wearables are calculating the RMSSD when sleeping or not moving.
So for instance, if a 42-year-old woman's Apple Watch says HRV of 44ms, it's telling her that:
(1) Her RMSSD "root mean square of successive differences" is 44ms.
(2) For her age the average expected measurement is (females between 40-50 years old): 27 ms. However, the range is quite large from the 5th to 95th centile: 14-48ms.
(3) This would mean that she is at the higher end of the HRV level and this would be interpreted as excellent. However, as she is 42 years old, she should be encouraged to continue with interventions to maintain her health, as it will inevitably decline with age.
So should my GP measure it?
Back to my original question. It is an easily accessible measurement that people have to hand. It will certainly complement an assessment of patient's health, but as an isolated measurement it has limited value.
Looking at trends over time is helpful. It is a great measure of cardiovascular autonomic function. It can also be used to assess someone's response to stress management strategies over time, which have positive downstream physiological consequences.
Knowing the whole picture is the key here. There is no major measurement that tells how healthy someone is. People are complicated, our bodies are wonders of nature and the HRV tells a tiny part of the story.
Selected References & Further Reading
Goldberger JJ, Arora R, Buckley U, Shivkumar K. Autonomic Nervous System Dysfunction: JACC Focus Seminar. Journal of the American College of Cardiology. 2019;73(10):1189-1206. doi:10.1016/j.jacc.2018.12.064.
Jarczok MN, Weimer K, Braun C, et al. Heart Rate Variability in the Prediction of Mortality: A Systematic Review and Meta-Analysis of Healthy and Patient Populations. Neuroscience and Biobehavioral Reviews. 2022;143:104907. doi:10.1016/j.neubiorev.2022.104907.
Petek BJ, Al-Alusi MA, Moulson N, et al. Consumer Wearable Health and Fitness Technology in Cardiovascular Medicine: JACC State-of-the-Art Review. Journal of the American College of Cardiology. 2023;82(3):245-264. doi:10.1016/j.jacc.2023.04.054.
El-Malahi O, Mohajeri D, Mincu R, et al. Beneficial Impacts of Physical Activity on Heart Rate Variability: A Systematic Review and Meta-Analysis. PLOS One. 2024;19(4). doi:10.1371/journal.pone.0299793.
Vann-Adibe S, Tsui HKH, Zhou HQ, et al. Efficacy and Methodology of Remote Heart Rate Variability Biofeedback Interventions for Mental Health: A Systematic Review and Meta-Analysis. Applied Psychophysiology and Biofeedback. 2025. doi:10.1007/s10484-025-09750-w.
Young HA, Benton D. Heart-Rate Variability: A Biomarker to Study the Influence of Nutrition on Physiological and Psychological Health? Behavioural Pharmacology. 2018;29(2-3):140-151. doi:10.1097/FBP.0000000000000383.
Mattos S, Rabello da Cunha M, Barreto Silva MI, et al. Effects of Weight Loss Through Lifestyle Changes on Heart Rate Variability in Overweight and Obese Patients: A Systematic Review. Clinical Nutrition. 2022;41(11):2577-2586. doi:10.1016/j.clnu.2022.09.009.
