The Foundation of Heartify’s Personalized Insights
Science
National Library of Medicine:
Applying Heart Rate Variability to Monitor Health and Performance in Tactical Personnel: A Narrative Review
DID YOU KNOW?
Every year, millions of people worldwide die from cardiovascular disease.
According to the World Health Organization, this is the no. 1 cause of death globally - so it is crucial to be proactive to prevent heart problems in the future. One of the indicators which help monitor heart health is HRV.
National Library of Medicine:
Heart Rate Variability: New Perspectives on Physiological Mechanisms, Assessment of Self-regulatory Capacity, and Health risk. (McCraty R, Shaffer F.)
What Is Heart Rate Variability?
HRV
Heart rate variability is an important indicator of overall cardiovascular health. It shows how your nervous system functions and the ability to respond to physical, mental, and emotional stressors. In recent years, there has been a resurgence of interest in HRV, thanks partly to technological advances that have made measuring more accessible.
Heart rate variability, or HRV, is a measure of time between each heartbeat, known as RR intervals. In other words, if your heart rate is 80 beats per minute, there may be 0.7 seconds between two beats or more – 1.20 seconds.
National Library of Medicine:
Real-world heart rate norms in the Health eHeart study (Robert Avram, Geoffrey H. Tison, Kirstin Aschbacher, Peter Kuhar, Eric Vittinghoff, Michael Butzner, Ryan Runge, Nancy Wu, Mark J. Pletcher, Gregory M. Marcus, and Jeffrey Olgin)
HRV VS. HR
Heart rate and heart rate variability are two different but interconnected measures. Your heart rate, also known as your pulse, is the number of times your heart beats per minute. An average resting heart rate should be between 60 to 100 beats per minute, but it can vary from minute to minute. While your pulse may feel consistent, the timing between heartbeats fluctuates.
HRV is the measure of the time interval between each heartbeat. These two are connected because HRV is affected by your heart rate. If your heart rate is too high, it can cause your HRV to be low. If your heart rate is too low, your HRV will increase. The ideal situation is to have a balance between the two measures.
HRV is the measure of the time interval between each heartbeat. These two are connected because HRV is affected by your heart rate. If your heart rate is too high, it can cause your HRV to be low. If your heart rate is too low, your HRV will increase. The ideal situation is to have a balance between the two measures.
What Is The Difference Between HRV And Heart Rate?
History
When did the history of HRV begin?
III-II century BC
The first written heart rate reports are established in the literature of Greek scientist Herophilos. Later, Archigenes continued his research and described the pulse and its characteristic features such as rate, rhythm, and volume.
1733
In 1733, Rev. Stephen Hales was the first one to demonstrate beat-to-beat variation and arterial pressure variation occurring during respiration.
1900
The concept of heart rate variability was later proposed in the early 1900s by Dr. Wilhelm Einthoven, who developed the first electrocardiogram (ECG). Dr. Einthoven noticed that the intervals between successive heartbeats were not always equal and proposed that this variability could be used to assess cardiac function.
1968
In 1968, American physiologist William Haslam Rosenbaum published a paper in which he used HRV to evaluate the autonomic nervous system.
1976
The breakthrough was in 1976 when Dr. Alan Waage and colleagues at the Norwegian Institute of Public Health found that patients with low HRV were at increased risk of death from cardiovascular disease over a follow-up period of 12 years. Since then, numerous studies have confirmed the predictive value of HRV for cardiovascular mortality.
1991
Cerulli introduced spectral analysis of HRV in rats in 1991. A year later, Zieglac introduced HRV spectral analysis in humans.
1996
Later in 1996, the European Society of Cardiology and the North American Society of Pacing and Electrophysiology defined the standards and guidelines to measure and interpret the HRV in the context of Healthcare.
2003
A study published in 2003 found that athletes who used HRV to monitor their training had a significantly lower risk of overtraining than those who didn't. This was one of the first studies to show the value of HRV for athletes.
2010
In 2010, Garmin released the first commercial HRV device, the Forerunner 610. This was a game-changer for athletes because it made HRV data more accessible and easier to use. Before the Forerunner 610, athletes had to go to a lab or clinic to get their HRV data. Now they can get it from their wristwatch.
2018
In 2018 alone, there were over 1,000 articles published on PubMed about heart rate variability. This shows just how far HRV has come in the past decade and how widely accepted it has become for well-being.
2020
The release of the Heartify App in 2020 - is a new and innovative way to calculate your heart rate variability, which shows accurate results about the condition of the heart. This marked the next level of heart measurements.
III-II century BC
The first written heart rate reports are established in the literature of Greek scientist Herophilos. Later, Archigenes continued his research and described the pulse and its characteristic features such as rate, rhythm, and volume.
1733
In 1733, Rev. Stephen Hales was the first one to demonstrate beat-to-beat variation and arterial pressure variation occurring during respiration.
1900
The concept of heart rate variability was later proposed in the early 1900s by Dr. Wilhelm Einthoven, who developed the first electrocardiogram (ECG). Dr. Einthoven noticed that the intervals between successive heartbeats were not always equal and proposed that this variability could be used to assess cardiac function.
1968
In 1968, American physiologist William Haslam Rosenbaum published a paper in which he used HRV to evaluate the autonomic nervous system.
1976
The breakthrough was in 1976 when Dr. Alan Waage and colleagues at the Norwegian Institute of Public Health found that patients with low HRV were at increased risk of death from cardiovascular disease over a follow-up period of 12 years. Since then, numerous studies have confirmed the predictive value of HRV for cardiovascular mortality.
1991
Cerulli introduced spectral analysis of HRV in rats in 1991. A year later, Zieglac introduced HRV spectral analysis in humans.
1996
Later in 1996, the European Society of Cardiology and the North American Society of Pacing and Electrophysiology defined the standards and guidelines to measure and interpret the HRV in the context of Healthcare.
2003
A study published in 2003 found that athletes who used HRV to monitor their training had a significantly lower risk of overtraining than those who didn't. This was one of the first studies to show the value of HRV for athletes.
2010
In 2010, Garmin released the first commercial HRV device, the Forerunner 610. This was a game-changer for athletes because it made HRV data more accessible and easier to use. Before the Forerunner 610, athletes had to go to a lab or clinic to get their HRV data. Now they can get it from their wristwatch.
2018
In 2018 alone, there were over 1,000 articles published on PubMed about heart rate variability. This shows just how far HRV has come in the past decade and how widely accepted it has become for well-being.
2020
The release of the Heartify App in 2020 - is a new and innovative way to calculate your heart rate variability, which shows accurate results about the condition of the heart. This marked the next level of heart measurements.
National Library of Medicine:
Stress and Heart Rate Variability: A Meta-Analysis and Review of the Literature (Hye-Geum Kim, Eun-Jin Cheon , Dai-Seg Bai, Young Hwan Lee, Bon-Hoon Koo)
National Library of Medicine:
Anatomy, Autonomic Nervous System (Joshua A. Waxenbaum; Vamsi Reddy; Matthew Varacallo)
HRV and ans
The hypothalamus is a small region in your brain that processes information and sends signals to the rest of your body through what we call "the autonomic nervous system". The ANS handles about 90% of automatic functions, including heart rate, blood pressure, respiration, and digestion.
The autonomic nervous system is a complex web of interconnected systems and consists of two parts – the sympathetic and parasympathetic nervous systems. The SNS increases the heart rate while activating "the fight-or-flight response." The PSNS does the opposite; it slows the heartbeat and controls the natural relaxation response.
The autonomic nervous system is a complex web of interconnected systems and consists of two parts – the sympathetic and parasympathetic nervous systems. The SNS increases the heart rate while activating "the fight-or-flight response." The PSNS does the opposite; it slows the heartbeat and controls the natural relaxation response.
How does it work: HRV and the autonomic nervous system?
The parasympathetic nervous system is responsible for the body's rest and digestion response when the body is resting or feeding. It slows down the heart rate and widens blood vessels.
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The sympathetic nervous system reflects responses to things like stress and exercise. This branch of the autonomic nervous system increases heart rate and blood pressure and constricts blood vessels.
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When these systems are in balance, your body can function at its best. HRV arises from these two opposing branches concurrently sending signals to your heart. A high HRV indicates that the sympathetic and parasympathetic systems work well together, and the body can adapt quickly to physical, mental, and emotional stressors. A low HRV may signify that the sympathetic nervous system is dominant and can lead to increased anxiety, difficulty sleeping, and other symptoms of stress. If one has a low HRV, it is essential to take steps to reduce stress and promote relaxation.
Journal of the American Heart Association
Heart Rate Variability for Risk Assessment of Myocardial Ischemia in Patients Without Known Coronary Artery Disease: The HRV-DETECT (Heart Rate Variability for the Detection of Myocardial Ischemia) Study
National Library of Medicine
Autonomic balance revisited: panic anxiety and heart rate variability (B H Friedman, J F Thayer)
National Library of Medicine
Psychological Stress and the Human Immune System: A Meta-Analytic Study of 30 Years of Inquiry (Suzanne C. Segerstrom and Gregory E. Miller)
National Library of Medicine
Obesity, Nutrition and Heart Rate Variability (Anna Strüven, Christina Holzapfel, Christopher Stremmel, and Stefan Brunner)
Juan Sztajzel
Heart rate variability: a noninvasive electrocardiographic method to measure the autonomic nervous system
Nocturnal heart rate variability in obstructive sleep apnoea: a cross-sectional analysis of the Sleep Heart Health Study
Matteo Bradicich, Noriane A. Sievi, Fabian A. Grewe, Alessio Gasperetti, Malcolm Kohler, Esther I. Schwarz
Using HRV
HRV is a great way to assess health and see what is happening with the heart. You can monitor the risk of developing heart disease and hypertension, track the immune response, and get an idea of how your body responds to training, life stressors, and recovery from workouts.