Today’s marketplace includes many self-quantitative metrics: wearable devices and applications that can change our health and lifestyle. Recently, heart rate (HR) and heart rate variability (HRV) have received a lot of attention. In order to determine when to use these two indicators correctly, it is important to understand the underlying science behind each indicator.
What is the difference between HR and HRV?
Heart rate (HR) is measured in beats per minute. It does not require exact time, just the average of the beats over a specific time period. For example, 60 HRs per minute may mean 1 runout per second, or may mean an average of 1 runout every 0.5 seconds, 1.5 seconds, 0.5 seconds, 1.5 seconds, etc. Heart rate measurement is a simple test that has existed for thousands of years due to low measurement technology requirements. Generally, a low HR indicates rest and a high HR indicates exercise or exercise. Heart rate focuses on the average number of heart beats per minute, while heart rate variability (HRV) measures the specific change in time (or variability) between consecutive heart beats. The time between beats is in milliseconds (ms) and is called “R-R interval” or “beat interval (IBI)”.
In general, a low HRV (or a small change in heart beat) indicates that the body is under stress from sports, psychological events, or other internal or external sources of stress. A higher HRV (or greater variability between heart beats) usually means that the body has a stronger ability to withstand stress or recover from previous stress. At rest, high HRV is generally advantageous, while low HRV is disadvantageous. A lower relative HRV is generally advantageous when in an active state, while a high HRV may be disadvantageous.
HRV is actually a general term for many different calculation and analysis methods. When these calculations are applied correctly, the autonomic nervous system (ANS) can be accurately measured. ANS is associated with every automated process in the body, including two main functions that control body pressure and recover from it. It regulates blood sugar, body temperature, blood pressure, sweat, digestion and more. When we want to track the target, identify the obstacle or during the measurement process, it is a great advantage to understand the state of the autonomic nerve under certain conditions through HRV.
Because the autonomic nervous system is closely related to many biological systems and processes, HRV will also be linked to cardiovascular, respiratory, digestive, and other recovery and stress-related systems. Since HRV focuses on an imperceptible change (in milliseconds) between each heartbeat, HRV is more complex and requires higher accuracy than heart rate. However, due to recent technological improvements, consumer-grade heart monitors and smartphone applications can do all the measurement work and visualize the results through the APP.
When to use heart rate (HR)？
Heart rate and heart rate variability are generally considered to be similar indicators, but their use is completely different when used correctly. It is best to use heart rate when exercising. It is an important tool for training the cardiovascular system or monitoring the impact of training on the cardiovascular system in real time.
When to use heart rate variability (HRV)？
HRV is best for rest (usually the first thing in the morning or the rest of the activity, such as meditation). It is an important tool for understanding overall health, resilience and ability to withstand various stresses. The HRV can be used as a daily checkup of the body to determine its readiness to tolerate stress on a particular date. In this regard, HRVs are often used to optimize and personalize plans based on an individual’s readiness or recovery status. In addition, HRV can be used to determine how various lifestyles affect health and performance through trending HRV and related events over time.