Merlin HRV


Since the introduction of the concept of homeostasis, biological science has been based on the rationale that all cells, tissues, and organs strive to maintain a static or constant “steady-state” condition. But with the introduction of signal processing technologies that are able to acquire continuous time series data from physiological processes such as heart rate, blood pressure, and nerve activity, it has become apparent that biological processes vary in complex and nonlinear ways, even during so-called “steady-state” conditions.

These observations have led to the understanding that healthy, optimal function is a result of continuous, dynamic, bi-directional interactions among multiple neural, hormonal, and mechanical control systems at both local and central levels. Together, these physiological and psychological regulatory systems are never truly at rest and are certainly never static. For instance, we now know that the heart’s normal resting rhythm is highly variable rather than being monotonously regular, which was long believed. These new findings have led to the investigation of the heart’s complex rhythms, or what is now known as heart rate variability (HRV).


What is HRV?

Heart rate variability (HRV) is tightly related to the workings of the autonomic nervous system (ANS). The ANS is part of the peripheral nervous system and acts as a control system, influencing the function of internal organs and helping maintain balance in the body. In most situations, we are unaware of the workings of the ANS because it functions in an involuntary, reflexive manner. Most of these bodily functions, such as digestion, perspiration, and dilation of the pupils, are generally performed without conscious control.

However, some of these activities also have a conscious element of control, such as breathing. Breathing is the only bodily function that is both involuntary (i.e. self-regulated) and voluntary (i.e. through conscious control). All it takes is a bit of training, and you can also have control over your heart rate. Therefore, breathing exercises are regarded as extremely important and useful in many religious, spiritual, martial art traditions, and modern medical and relaxation techniques.


Why HRV?

Stress is prevalent in today’s society as our work and personal lives become increasingly busier. Simply put, stress is not going away any time soon. New research shows that the heart has its own nervous system, its own intelligence, and that the brain and heart are in a two-way communication link, influencing each other in a synchronized manner. An indication of your stressed state can be found by analyzing your HRV—the time interval between heartbeats—measured by the variant between beat-to-beat intervals. In fact, the sporadicness of the interval between beats is highly dependent on how stressed you are.

An optimal level of HRV within an organism reflects healthy function and an inherent self-regulatory capacity, adaptability, or resilience. Too much instability, such as arrhythmias or nervous system chaos, is detrimental to efficient physiological functioning and energy utilization. However, too little variation indicates age-related system depletion, chronic stress, pathology, or inadequate functioning in various levels of self-regulatory control systems.


How is HRV measured?

Simply put, heart rate variability (HRV) refers to the beat-to-beat alterations in heart rate or pulse. Most people think the heart is like a metronome, and beats vary evenly from one beat to the next. But the reality is that how your heart beats depends on how much stress and fatigue you’re under. When you’re under a lot of mental stress or you’re not sleeping well, you see a very specific pattern in the heart rate as opposed to when you’re well rested. A higher HRV suggests a relaxed, low-stress physiological milieu, while a lower HRV indicates a need for recovery, rest, and sleep.

With all the advancement in mobile technology, measuring your HRV via apps and portable sensors has been made possible. One of the pioneers in this field would be the HeartMath Institute, who have come out with some really interesting self-monitoring products such as the Inner Balance sensor. Products such as Merlin’s Heart Rate Monitor connect to your smartphone via Bluetooth to give you instant reading of your heart rate, HRV, calories burned, and other parameters (when used with other third-party fitness apps).


How does HRV benefit me?

The importance of HRV as an index of the functional status of physiological control systems was noted as far back as 1965 when it was found that fetal distress is preceded by reductions in HRV before any changes occur in heart rate itself. Low HRV is linked to depression, poor health outcomes, cardiac symptoms, and high stress levels. On the other hand, higher HRV is reflective of better physical and emotional health and has been shown to reduce the risk of stress-related illnesses such as cardiac problems, asthma, and diabetes.

Coherence is a state of synchronization between your heart, brain, and autonomic nervous system, which has been proven to have numerous mental, emotional, and physical benefits. According to many new studies, emotional self-regulation strategies may contribute to improved client health and performance, alone, or in combination with HRV biofeedback training. Numerous studies have provided evidence that coherence training consisting of intentional activation of positive emotions paired with HRV coherence feedback may facilitate significant improvements in wellness and wellbeing indicators in a variety of populations.


Source: Heart Rate Variability: New Perspectives on Physiological Mechanisms, Assessment of Self-regulatory Capacity, and Health Risk – Global Advances in Health and Medicine (January 2015, Volume 4, Number 1)