Heart Rate Variability Overview

The change in heart rate that occurs with each breath. During inhalation, heart rate increases, and during exhalation, it decreases.

The variation in the time between heartbeats.

The standard deviation of the intervals between heartbeats (R-R intervals).

The time interval between two consecutive peaks of the QRS complex in an electrocardiogram (ECG).

A measure of breathing rate that is often used to assess respiratory sinus arrhythmia. It is based on the concentration of carbon dioxide in the air.

The autonomic nervous system (ANS) controls the heart rate. This includes the sympathetic nervous system (SNS), which increases heart rate, and the parasympathetic nervous system (PNS), which decreases heart rate.

Variations in chest pressure during breathing can affect heart rate.

A recording of electrical activity in the heart. It shows distinct peaks called the QRS complex, which are used to calculate heart rate variability.

A measure of heart rate variability calculated by taking the root mean square of the differences between successive R-R intervals. It reflects the variation in time between heartbeats.

A physiological signal obtained from a sensor that measures the pressure changes in the blood vessels. It can be used to estimate heart rate variability.

The influence of the sympathetic and parasympathetic nervous systems on heart rate. A high heart rate variability suggests strong parasympathetic influence.

A metric used to quantify the influence of the sympathetic and parasympathetic nervous systems on heart rate variability. It measures the variation in heart rate in different frequency bands.

A measure of the oxygen saturation in the blood. It is often measured along with heart rate.

A period of time when the body is at rest and not undergoing any physical or mental exertion.

High heart rate variability is often associated with a state of recovery and low stress. It indicates a strong influence of the parasympathetic nervous system.

Low heart rate variability can be caused by intense training, stress, or illness. It indicates a stronger influence of the sympathetic nervous system, putting your body in a more active, alert state.

HRV is most informative during rest, providing insights into an athlete's recovery levels.

Higher HRV at rest indicates good recovery, suggesting strong parasympathetic activity.

Lower HRV at rest signals poor recovery, likely indicating weakened parasympathetic activity.

HRV is influenced by the type of athlete being studied, with recreational athletes showing greater fluctuations in HRV than highly trained athletes due to training stress.

HRV is a valuable tool for monitoring recovery and predicting the need for rest periods in athletes.

HRV is often oversimplified in interpretation, requiring nuanced understanding for accurate analysis.

While HRV is useful, it's not the perfect measure for assessing training stress during exercise, as heart rate remains the more relevant indicator.