Heart rate variability (HRV) is the time difference between heart beats. HRV is somewhat like a barometer of our human health. However, many people do not know what HRV is, so today we will talk about HRV.
1. What is HRV?
From the medical point of view, HRV refers to the time difference between successive heartbeats. Unlike rhythmic music, the beating of our human heart is not always constant. For example, your measured heart rate is 70, which actually represents your constant heart rate. The actual situation may be that your last heart beat interval is 1 second and the next one is 0.8 seconds. This difference in heart beat is called HRV.
If the difference between every two beats and the interval is not large, the HRV is relatively low. On the contrary, if there is a large difference between the intervals of every two heartbeats, the HRV will be higher.
The interval between heartbeats is generally in milliseconds and is calculated by the interval between the peak R and the R point in the ECG wave group (R-R interval). This cardiac irregularity can reflect a person's cardiovascular, cerebrovascular, heart, stress, anxiety, sleep and other conditions. Because HRV is mainly controlled by our autonomic nervous system, and the autonomic nervous system in the human body regulates the functions of the body that are not subject to subjective control: heartbeat, respiration, blood pressure and digestion. Therefore, we say that HRV is a barometer of human health, which can reflect the working condition of our autonomic nerves, so that we can know our own physical condition. Generally speaking, the higher the HRV, the better, representing better cardiovascular function and stress resistance. The lower the HRV, the higher the risk of anxiety, depression incidence rate and cardiovascular disease mortality.
2. How to monitor HRV?
On the market, some professional smart watches, chest bands, rings and watches, such as apple watch, Garmin, veepooRIG, Fitbit, etc., all support the monitoring of heart rate variability.
Different equipment has different calculation methods, and the measured results will be different. After we have collected the ECG data through the wearable device, we need to conduct some preprocessing analysis before statistical analysis to convert it into a statistical value.
In fact, both heart rate and heart rate variability data are derived from the voltage value of heart activity changes captured by the device. Moreover, there is no optimal standard interval for HRV, because it is affected by many factors such as age, hormones and lifestyle. The most useful value of HRV is to compare it with your own basic value when there is no comparison of the same population. Moreover, different people want to obtain the original heart rate data for analysis and scientific research, and have different requirements for accuracy. Therefore, they have different requirements for equipment.
3. Role of HRV analysis
HRV will be affected by environmental factors, such as stress, which will inhibit your parasympathetic nerves and activate your sympathetic nerves, thus reducing HRV rate.That may caused by some reasons: excessive pressure, emotional fluctuation, poor sleep quality, etc. In addition, smoking, alcohol consumption and some drug effects may also reduce HRV.
If there is a continuous sudden drop in HRV, it is sometimes a precursor of illness, which reminds you to pay attention to rest. On the contrary, it is likely that you have been in good physical condition recently, such as eating healthy, sleeping well, or exercising to a certain extent. In short, monitoring HRV can help you understand your health. Especially in the following situations:
When you are in emotional instability
Research on emotional instability shows that people with lower resting HRV are more difficult to regulate their emotions.If you feel that your mood fluctuates greatly, you can use wearable devices for HRV monitoring.
Can't distinguish emotions well
Can't control impulse well so when your HRV is low, you can check whether you have emotional problems. Know your own mood fluctuations in time, and do a good job in prevention and relief.
When you start doing exercise
If you are exercising or have a habit of long-term exercise, HRV monitoring can also help you better plan your training.
When your HRV is high, you are more suitable for high-intensity training;
When your HRV is low, the training with relatively low intensity will be more suitable for you.
Detecting HRV can prevent you from overtraining, reduce your risk of injury, and keep you playing at a high level.