There is quite a distinct difference between Heart rate variability (HRV) and heart rate (HR). Heart rate (HR) refers to the number of times that the heart beats per minute, such as 65 bpm. It is measured using a pulse oximeter. The normal heart rate of a person is 60-100 beats per minute. A person has a higher heart rate if they are involved in physical activities such as exercise. The heart rate is generally lower when a person is at rest.
Heart rate variability (HRV) on the other hand refers to the variations in time between successive heartbeats. This time is usually measured in terms of milliseconds (ms). This variation is often referred to as the R-R interval or the inter-beat interval (IBI). It is measured using an Electrocardiogram (ECG) machine. Presently, there are also heart monitors and smartphone applications that can be used in the measurement of HRV. They employ the use of photoplethysmography (PPG) technology in measurement and obtaining relatively accurate results.
Heart rate variability (HRV) is usually indicative of the state of the autonomic nervous system (ANS) of the body. A lower HRV is triggered by the sympathetic nervous system. This occurs when the body is experiencing stress during exercise, or as a result of a psychological event.
These stressors can either be internal or external. On the other hand, a higher heart rate variability is triggered by the parasympathetic nervous system when the body is in a state of rest. This occurs during recovery from a stressful situation or when the body is able to tolerate a particular stressor. A key point to note when dealing with HRV is that in a state of rest, your HRV should be high, and in a state of activity, your HRV should be lower.
Advantages and Disadvantages of using heart rate variability (HRV)
There are advantages and disadvantages of using both parameters in monitoring. The advantages of using heart rate include that it is easy to measure both while resting or when involved in an activity such as working out. It mainly targets aerobic exercises and extreme accuracy is not necessary.
Using heart rate, you can easily gauge the level of exertion applied to the cardiovascular system during strenuous exercise. Lastly, there is a wide range of devices that are used to measure heart rate.
The disadvantages of using heart rate include that it is a vague and inconsistent indicator of the activities of the cardiovascular system while at rest, can only be used in monitoring activities of the cardiovascular system, and the fact that most of the devices used have varying accuracies in determining the exact values.
The advantage of using heart rate variability (HRV) is that it is a reliable indicator of the activities of the autonomic nervous system, it also indicates the activities of the other bodily systems including the cardiovascular and respiratory systems. The main disadvantage is the difficulty experienced in measuring heart rate variability (HRV) when performing an activity such as exercise.
Most people consider heart rate and heart rate variability (HRV) as similar metrics. This is however not the case as explained above. They also have very distinct uses.
Heart rate is mainly used during exercise and training to monitor the effects of workout sessions on the cardiovascular system. HRV on the other hand is used to understand the overall body health, to identify the resilience of the body as well as its ability to tolerate various stress levels.