What is the uniqueness of HRV and its value in smart watches

Heart rate variability is unique

“High” and “low” HRV are relative to everyone. HRV is a highly sensitive indicator, it has a unique response to everyone. Some people have stable HRV scores, while others fluctuate greatly. HRV is a constantly evolving tool, which means that at each HRV level, personal HRV scores and physical status observations are particularly important.

The normal HRV for adults can range from less than 20 to more than 200 milliseconds. The best way to get a normal level is to use a wearable device to measure your HRV in a controlled environment (such as sleep) and establish a baseline within a few weeks.

Everyone’s HRV is unique. Compare HRV to the average and avoid comparisons with others. Daily and seasonal fluctuations in HRV are normal.

There are many factors that affect ANS, and therefore HRV:

Influencing factors

Heart rate variability has short-term and long-term trends

Because HRV is responsive, there are multiple touch points that can provide insight. Useful tracking indicators are:

Short-term and long-term

Each indicator provides different insights. The comparison of the average nightly HRV with the baseline and whether it is rising or falling can help understand how to spend the day. Comparing the general baseline of check-in during the day can provide insight into how certain activities (such as meditation or exercise) affect the body system. The HRV trend and HRV balance within a few weeks can help determine whether you have successfully recovered from the hard days. Changes in HRV over a few months can reveal how major lifestyle changes affect health.

Heart rate variability has a natural high and low

Some explanations of HRV are too simplistic, asserting that high numbers are always good and low ones are always bad. It is much more complicated.

Although high HRV is usually positive, in some cases, low HRV is necessary or even desirable. For example, during strenuous exercise, low HRV reflects that the fight or flight system is properly controlling the heart rate for activity. HRV will rebound afterwards because the rest and digestive system will take over to help recovery.

These fluctuations occur throughout the day as different sources of daily stress constantly challenge the system. Just being excited, or moving from the sofa to the bathroom, can change your HRV at any given moment. By measuring HRV during the day, the body’s response to these fleeting changes can be captured. If you want to understand chronic physiology, the best time to measure HRV is when you sleep. At night, the body is in a consistent state without any confounding variables.

Which models are important?

Monitoring your HRV can achieve maximum productivity, manage stress, and fine-tune training programs.

The nightly HRV reading can show:

· Higher HRV scores reflecting rest days, cool bedrooms, or “conscious” low/moderate intensity activities (such as hiking or yoga)

· Lower HRV scores caused by dehydration, alcohol, dinner or exercise, illness, high-intensity exercise, acute stress, or a hot bedroom

You may notice that HRV varies greatly from day to day. If you are looking for patterns, what matters is the HRV trend. Over time, do you move up or down?

HRV not only reflects the health of the human heart, but also the nervous system of the human body. Therefore, it is very important for us to accurately grasp the HRV data. In the past, the monitoring of HRV was mainly through medical devices. However, since smart watches have applied the HRV function to them, the monitoring of HRV has become more convenient.

Especially since 2020, manufacturers such as Huawei, Apple, Samsung, OPPO, Xiaomi, Huami, Veepoo have developed the HRV function to the extreme and put it into use on their products, especially the newly developed product Watch RIG of Veepoo. The ECG signal sampling frequency can reach 512HZ. The standard has reached the medical level. In the future, the application of HRV in smart watches will be more accurate.