What is heart rate variability?
Heart rate variability (HRV) measures the time difference between each heartbeat.
What controls heart rate variability?
The autonomic nervous system (ANS) controls the HRV. ANS is divided into two parts: the sympathetic nervous system and the parasympathetic nervous system, which regulate heart rate, blood pressure, digestion and breathing. These two components are called the fight or flight system and the relaxation response.
The hypothalamus is a small area located above the brain stem. It continuously processes information and transmits signals to other parts of the body through ANS. These signals can relax or stimulate different functions of the body, including HRV. According to the way the body reacts, especially in the case of continuous negative signals, it will affect the function of the fight or flight response, forcing the heart rate to overspeed.
Although the ANS affects the heart rate, the sinus node (SA node) is a natural pacemaker that controls the heart rate, so the heart beats according to its rhythm. The SA node keeps the heart beating about 100 beats per minute.
ANS affects heart rhythm at the cellular level:
· The relaxation response tells the heart to slow down, leaving room for changes between beats. The brain's "fight or flight" system tells the heart to accelerate, thereby reducing the room for change
The impact of ANS on HRV is more direct and more important. In daily life, we should pay more attention to the health of HRV. But how should we monitor HRV?
In addition to traditional medical equipment, what else can there be? Now there are some smart watches on the market that can monitor HRV. The data monitored by these smart watches can deliver accurate HRV data to the wearer in real time.
Why check heart rate variability?
· It can identify ANS imbalance. When the system is in battle or flight mode, the difference between heartbeats is larger when in relaxation mode, and the difference between heartbeats is smaller.
· HRV can detect the pressure level. People with low HRV are more likely to feel acute stress, while people with high HRV are rarely stressed and their cardiovascular system is in good condition. Checking the HRV can help understand how to deal with stress in a healthier way.
· May increase awareness of lifestyle habits. Checking the HRV is a way to understand the health or unhealthy effects of lifestyle on the heart, and it is also a great tool to stimulate behavior change.
· It can detect reactions to the environment and emotions. When tracking HRV, the nervous system can respond to the environment, feelings, and emotions.
· Can improve self-awareness. HRV measurement helps to improve understanding of how life and thinking and behavior affect the nervous system and bodily functions.
HRV has an intuitive impact on all aspects of human health. We should pay more attention to the normal data of HRV. We can use smart watches, such as Huawei, Apple, Samsung, OPPO, Xiaomi, Huami, Veepoo and other manufacturers have developed the HRV function to the extreme, and put it into use on their products, especially Veepoo’s newly developed product Watch RIG. The ECG signal sampling frequency can reach 512HZ. And in 2021, OnePlus and Meizu also joined the smart watch market. When using Watch RIG for HRV monitoring, it only takes 30 seconds to get the result. Now the standard of HRV monitoring has reached the medical level. In the future, the application of HRV in smart watches will be more accurate.