What is heart rate variability (HRV)?
Our heart does not beat at a constant frequency. Heart rate variability (HRV) is the physiological phenomenon of variation in the time interval between heartbeats.
It is measured by the variation in thebeat-to-beat interval.
HRV is an accurate, non-invasive measure of the Autonomic Nervous System (ANS) – which responds to everything: how you exercise, recover, eat, sleep and perceive
stress. Unlike basic heart rate (HR) that counts the number of heartbeats per minute, HRV looks much closer at the exact changes in time between successive heartbeats
(also called inter-beat intervals, RR intervals, NN intervals, etc).
Heart Rate Variability and the Autonomic Nervous System
HRV is regulated by the autonomic nervous system (ANS), and its sympathetic and parasympathetic branches, and it is commonly accepted as a non-invasive marker
of autonomic nervous system activity. The sympathetic branch of the ANS is the stress or fight or flight system, getting us ready to act, react, and perform – to meet the
different demands that life throws at us. The parasympathetic side is characterized as the rest and digest system that allows the body to power down and recover “once
the fight is over”. The sympathetic branch activates stress hormone production and increases the heart’s contraction rate and force (cardiac output) and decreases HRV,
which is needed during exercise and mentally or physically stressful situations. Conversely, the parasympathetic branch slows the heart rate and increases HRV to restore
homeostasis after the stress passes. This natural interplay between the two systems allows the heart to quickly respond to different situations and needs.
Application of Heart Rate Variability
Today, we can use HRV to:
◆Improve resilience and adaptability
◆Optimize training and recovery
◆Personalize nutrition and sleep
◆Improve mental health – mood, depression, anxiety
◆Improve mental performance and cognition
◆Identify risk of disease, morbidity and mortality
◆Measure systemic inflammation
◆Track progress and guide treatment plans
◆Re-balance the nervous system with live biofeedback
◆Objectively understand motivation and willpower
◆Provide early warning signs for changes in health, overtraining or maladaptation