So, how do fitness trackers measure blood pressure? In short, a fitness tracker can measure blood pressure in three ways: optical sensor, ECG, and inflation-based method. Thus, the results may be different from the doctor’s equipment.
I suggest you read this blog fully to know the complete functions of fitness trackers, specifically in monitoring blood pressure. You will learn an overview of fitness trackers’ different methods of measuring BP. As a bonus, you will get some tips for better accuracy in measuring BP using a fitness tracker.
The Basics of a Fitness Tracker – How It Functions
You can wear a fitness tracker to track other health and fitness metrics. Day by day, they are taking the spots of wristwatches for increased facilities. They can be – a sleep monitor, pedometer, receiving phone calls, SMS, GPS location, and showing a notification. Also, some devices may include advanced features such as water resistance, mobile payments, or voice assistants.
You can find these trackers in versatile colors and designs though mostly wearable as a wristwatch. A small display screen (LCD) shows time and other metrics. Also, it may have additional buttons or touch controls for navigation. Once you charge the tracker, it may run for 3-15 days on average.
If you own a fitness tracker, you may discover it has several sensors to work precisely. For example:
- A pedometer sensor tracks the steps you have taken.
- An accelerometer sensor can track the distance you have traveled and the calories you have burned.
- A heart rate sensor uses optical sensors, ECG, and PPG to measure heart rate and blood pressure.
- A sleep tracker uses movement sensors to track your sleep patterns and duration.
- A gyroscope can help you in orientation and rotation.
- An altimeter can provide measurements while you are climbing higher (e.g., mountain).
- A temperature sensor tracks your body temperature consistently.
- A SpO2 monitor can detect blood oxygen levels instantly (e.g., Willful Fitness Tracker).
After installing a dedicated app, you can connect the tracker to a smartphone or computer using Bluetooth, internet, and USB connections.
How Do Fitness Trackers Measure Blood Pressure?
This section will explain some fitness tracker features for blood pressure monitoring. Indeed, fitness trackers are gaining popularity as people now want instant information on their health. Blood pressure monitoring is one of the essential metrics they look for in a fitness tracker.
You can measure your blood pressure if your fitness tracker has any of these features:
Optical Sensors
Have you ever checked the bottom part of a fitness tracker? A bright light may shine in this area, which is an optical sensor.
“The sensors can be used to measure the rate at which blood is pumped through the capillaries.
Optical sensors work by shining a light onto the skin and measuring the reflection of the light. Through this, the tracker can measure the blood volume changes in the arteries. Then, it provides an estimate of the blood pressure.
Fitness trackers with optical sensors are easy to use. But the accuracy of reading may be affected by several factors. They can be skin color, ambient light, and motion artifacts.
Electrocardiography (ECG) and Photoplethysmography (PPG)
These features are the latest additions to modern fitness trackers for our wellness. You can find “watches that track your ECG and identify atrial fibrillation (Afib).
Electrocardiography (ECG) can calculate the electrical activity of our heart. Alternatively, photoplethysmography (PPG) can track blood volume changes in our arteries. With the combination of these two sensors (or methods), a fitness tracker can show more accurate readings of BP.
ECG and PPG are complex ways to measure blood pressure. That’s why a fitness tracker needs more advanced sensors.
Inflation-Based Measurement
Some fitness trackers use inflation-based measurements to measure blood pressure. It features inflating cuff around the upper arm. When the cuff deflates, the device can measure the changes in blood pressure. However, you may need a separate device (sphygmomanometer) to use the fitness tracker with this feature.
According to American Heart Association, a fitness tracker with an inflatable cuff can provide more accurate information than any wrist or finger monitor. They can even be better than devices with optical sensors and ECG or PPG.
Accuracy of Fitness Tracker Blood Pressure Measurements
The accuracy of blood pressure is extremely important to identify and manage high BP. If the measurement is inaccurate, it may possibly lead to incorrect diagnoses and treatment. However, fitness tracker measurements can be different due to several factors:
- The way you wear it. For example, wearing too loose or too tight can impact the BP measurement accuracy.
- You need to keep your hand steady to get more accurate results.
- If you choose a fitness tracker with an optical sensor, you may get less accurate results, especially if you have a darker skin tone.
- You may get more accurate measurements if you calibrate the device properly over time.
Fitness Tracker Measurements VS. Standard BP Measurements
Several studies may prove that fitness tracker BP measurements can be less accurate than standard ways (using a cuff and stethoscope). Even in a study by Helmond et al. (2019), devices like the Everlast smartwatch (a fitness tracking watch) and BodiMetrics Performance Monitor are not perfectly fit as BP monitors.
Still, the difference in accuracy in the latest fitness trackers is lower compared to standard monitors. Again, the fitness tracker sensors can provide different accuracy. For example, optical sensors are less accurate than ECG/PPG or inflation-based measurements.
Many people consider inflation-based measurement more accurate for BP monitoring. But as I said, you need a different device to use this method. That’s why many fitness trackers do not have any inflation cuff.
How Can I Get More Accurate Blood Pressure Measurement Using a Fitness Tracker?
Accuracy of measurement is always an essential factor for a fitness tracker BP monitor. Thus, you can follow these instructions to get better accuracy while you measure blood pressure:
Proper Tracker Placement
You should place the fitness tracker on your wrist perfectly. It should be snug but not too tight or too loose. Hence, check if the sensor is appropriately aligned with your wrist. Also, you should wear the device on the wrist closest to your heart. You should avoid motion artifacts during the measurement for better accuracy.
Regular Calibration and Maintenance
Fitness trackers like LETSCOM Fitness Tracker may require regular calibration and maintenance. You should read and follow the manufacturer’s instructions to calibrate the tracker. Consequently, you should keep it clean and free of dust and debris for better accuracy.
Consistent Tracking Habits
You should make a habit of tracking blood pressure at the same time each day. I suggest using the fitness tracker in the morning before any physical activity. Again, avoid drinking caffeine or alcohol, smoking, or eating a large meal before you measure your BP with a fitness tracker. They may hamper the result of measuring blood pressure.
Track the blood pressure regularly to figure out any changes or trends. It will give you a better idea about your health condition. Then, discuss the gathered data from the tracker with your healthcare provider.
Frequently Asked Questions
Q1. Can fitness trackers accurately measure blood pressure?
Studies have found that fitness trackers can be less accurate than standard blood pressure measurements. But the difference is slight (like within 5mmHg). However, sensors and the placement of fitness trackers may impact the accuracy of measurements.
Q2. How does measuring blood pressure happen using a fitness tracker?
A fitness tracker can measure blood pressure using different methods like optical sensors, ECG, PPG, and inflation cuff. The result may vary depending on these sensors. Optical sensors may provide less accurate results than ECG, PPG, or inflation-based fitness trackers.
Q3. What is the most accurate way to measure blood pressure?
The most accurate way to measure blood pressure is with an inflatable cuff and a stethoscope, typically performed by a healthcare professional. But you can get almost similar readings from a modern fitness tracker.
Conclusion
Are you a fitness enthusiast or simply looking to take control of your health and well-being? Then, I am sure this post has been the right place for information for you. You have learned about “how do fitness trackers measure blood pressure.”
Therefore, I have discussed several matters regarding fitness trackers. Now you know about functions, sensors, and the accuracy of a tracker in terms of BP monitoring.
If you have any questions, please add them in the comment section. Thanks for your valuable moments.