Blood pressure, BMI, cholesterol — biological measures of well-being, often referred to as biomarkers, are part of the everyday lexicon we use to define and describe the state of our physical health.
Each of these measures tells us something about how our body is functioning, warning us about potential risks and imbalances which we can then take steps to correct.
But the world of biomarkers can often seem daunting. How do we know which biomarkers to pay attention to? And how do we apply their measurements to actually make concrete changes to our own health? The sheer number of biomarkers to potentially worry about can feel quite overwhelming.
Enter heart rate variability, or HRV for short: a comprehensive biomarker that can tell us simultaneously about our physical and psychological health — in one convenient measurement.
What is HRV?
Put simply, HRV is a measure of the amount of variation between beats in your heart rate.¹ We often think of our heartbeat as a steady, uniform pulse — but in reality, a healthy person’s heart rate changes quite a lot throughout the course of a day.
When you’re in a stressful situation, for example, your autonomic nervous system activates a sympathetic response that makes your body more alert and focused. Your heart rate jumps, and you experience that familiar adrenaline rush as your body prepares to deal with the threat.²
Once the threat is gone, the parasympathetic response kicks in, returning your heart rate to its resting level and allowing you to calm back down.³
So, for a normal person, a high level of HRV is good! It tells you that your cardiovascular system and your nervous system are functioning normally, able to effectively respond to stressful situations.
But if your HRV is low, your body isn’t so good at responding to stress: your cardiovascular system may be impaired in some way, or your psychological ability to deal with stressful situations might be reduced.⁴ As a result, we can view HRV as a broad measure of both physical and psychological health.
Risk Factors and HRV
A low HRV is correlated with several major categories of health problems, both physical and mental.
Firstly, HRV tells you about your risk of cardiovascular diseases. Low HRV measurements are associated with diabetes, heart disease, and obesity⁵, as well as a higher risk of sudden death from cardiovascular issues.⁶ HRV measurements can be a useful way to monitor heart health, especially if you are diagnosed with or at risk of developing heart disease.
Secondly, HRV tells you about your body’s responsiveness to stress. When you experience chronic stress, your nervous system’s sympathetic response is constantly being overexerted; over time, its ability to effectively regulate heart rate declines, resulting in a lower HRV.⁷
People who are clinically depressed⁸, as well as people who experience high levels of stress⁹ and overcommitment¹⁰ in the workplace, tend to have low HRV measurements.
Applications of HRV
Put simply, HRV shows us that physical and psychological health are intimately connected. When you’re chronically stressed, it’s not only your mental state that is affected — your cardiovascular health suffers as well.
So how can we use HRV to make practical lifestyle changes? Fortunately, scientists have done a lot to answer that question for us.
Mindfulness meditation¹¹, emotion regulation training¹², and physical exercise¹³ have all been studied as methods to raise HRV to a healthy level — allowing you to reduce stress, bolster heart health, and even improve productivity and cognitive function.¹⁴
Studies have suggested that you can learn to deliberately raise your HRV by practicing controlled breathing techniques.¹⁵ Some workplaces have even implemented HRV biofeedback programs, allowing employees to monitor their heart health in real time using electronic devices.¹⁶
In today’s world, too many of us are burdened with chronic stress and poor physical health. Perhaps it’s time to start listening to our bodies and learning what they can tell us.
Biomarkers like HRV may very well be the future of modern health, allowing us to directly monitor our own body and intervene with positive, productive lifestyle changes.
1. Sztajzel, J. (2004). Heart Rate Variability: A Noninvasive Electrocardiographic Method to Measure the Autonomic Nervous System. Swiss Medical Weekly, 134, 514–522. doi: 2004/35/smw-10321 2. Kristal-Boneh, E., Raifel, M., Froom, P., & Ribak, J. (1995). Heart Rate Variability in Health and Disease. Scandinavian Journal of Work, Environment & Health, 21(2), 85–95. doi: 10.5271/sjweh.15 3. Ibid. 4. Sztajzel (2004) 5. Young, H. A., & Benton, D. (2018). Heart-Rate Variability: A Biomarker to Study the Influence of Nutrition on Physiological and Psychological Health? Behavioural Pharmacology, 29(2), 140–151. doi: 10.1097/FBP.0000000000000383 6. Kristal-Boneh et al.(1995) 7. Kim, H.G., Cheon, E.J., Bai, D.S., Lee, Y. H., & Koo, B.H. (2018). Stress and Heart Rate Variability: A Meta-Analysis and Review of the Literature. Psychiatry Investigation, 15(3), 235–245. doi: 10.30773/pi.2017.08.17 8. Schiweck, C., Piette, D., Berckmans, D., Claes, S., & Vrieze, E. (2019). Heart Rate and High Frequency Heart Rate Variability During Stress as Biomarker for Clinical Depression. A Systematic Review. Psychological Medicine, 49(2), 200–211. doi: 10.1017/S0033291718001988 9. Chandola, T., Heraclides, A., & Kumari, M. (2010). Psychophysiological Biomarkers of Workplace Stressors. Neuroscience & Biobehavioral Reviews, 35(1), 51–57. doi: 10.1016/j.neubiorev.2009.11.005 10. Garza, J. L., Cavallari, J. M., Eijckelhof, B. H. W., Huysmans, M. A., Thamsuwan, O., Johnson, P. W., … Dennerlein, J. T. (2015). Office Workers with High Effort–Reward Imbalance and Overcommitment Have Greater Decreases in Heart Rate Variability Over a 2-H Working Period. International Archives of Occupational and Environmental Health, 88, 565–575. doi: 10.1007/s00420–014–0983–0 11. Heckenberg, R. A., Eddy, P., Kent, S., & Wright, B. J. (2018). Do Workplace-Based Mindfulness Meditation Programs Improve Physiological Indices of Stress? A Systematic Review and Meta-Analysis. Journal of Psychosomatic Research, 114, 62–71. doi: 10.1016/j.jpsychores.2018.09.010 12. McCraty, R., Atkinson, M., & Tomasino, D. (2004). Impact of a Workplace Stress Reduction Program on Blood Pressure and Emotional Health in Hypertensive Employees. The Journal of Alternative and Complementary Medicine, 9(3), 355–369. doi: 10.1089/107555303765551589 13. Lin, S.L., Huang, C.Y., Shiu, S.P., & Yeh, S.H. (2015). Effects of Yoga on Stress, Stress Adaption, and Heart Rate Variability Among Mental Health Professionals — A Randomized Controlled Trial. Worldviews on Evidence-Based Nursing, 12(4), 236–245. doi: 10.1111/wvn.12097 14. Sutarto, A. P., Wahab, M. N. A., & Zin, N. M. (2010). Heart Rate Variability (HRV) Biofeedback: A New Training Approach for Operator’s Performance Enhancement. Journal of Industrial Engineering and Management, 3(1), 176–198. doi: 10.3926/jiem..v3n1.p176–198 15. Ibid. 16. Ibid.