Garmin’s slim swim-friendly wearable Vivosmart 4 comes packed with many health and fitness features.
One of these features is the Vivosmart’s pulse oximeter (SpO2 feature) which can help you and your family monitor and assess your blood oxygen levels in these worrying times.
Contents
- 1 What is pulse oximetry?
- 2 How does Vivosmart Pulse Oximeter work?
- 3 How to use the Vivosmart pulse oximeter feature to measure blood oxygen at the moment?
- 4 How to read Vivosmart pulse oximeter reading
- 5 How accurate are the Vivosmart’s Pulse Oximeter and Garmin’s Pulse Ox feature?
- 6 Vivosmart Blood Oxygen readings not working? Check these tips
Related reading
- How does Apple Watch Series 6 Blood Oxygen (SpO2) monitoring compare with others
- How do I run a Lactate Threshold Test on my Garmin Smart Watch?
- Amazfit adds new features for Stress and SpO2 readings to its app
- Does Fitbit, Garmin, or other wearable devices offer a Pulse Oximeter?
- Stressed out? Try one of these wearables for stress detection and management
- Turn your smartwatch into biochemical monitoring system with special adhesive
- How to contact Garmin Customer Support about issues and warranty info
What is pulse oximetry?
If you’ve ever visited an emergency room or urgent care clinic, you probably had a pulse oximeter placed on your finger.
Unlike a clinical setting, many wearables, including Garmin’s Vivosmart 4 and Apple’s Series 6+ watch, now include pulse oximeter sensors on their smartwatches and smart trackers.
You use a pulse oximeter to check if there is enough oxygen in your blood.
Your body depends on good blood oxygenation to function well.
Pulse oximeters are pain-free and non-invasive tests (no pricks) that measure the oxygen level (oxygen saturation) of the blood.
They examine how well you send oxygen via hemoglobin (a blood protein) to parts of your body furthest from your heart, such as the arms and legs.
Hemoglobin resides inside your red blood cells and its what makes your blood cells appear red.
Pulse oximeters can even detect small changes in how efficiently hemoglobin carries oxygen to your arms or legs and other body parts.
Typically, a person’s blood oxygen saturation level is normally between 95–100%. These oxygen levels tend to remain stable, regardless of activity including exercise or sleep. 
If your device’s pulse oximeter says 95%, that means each of your red blood cells is made up of 95% oxygenated and 5% non-oxygenated hemoglobin.
Blood oxygen saturation levels are a concern when they drop consistently below 92%–that could be a sign of poor blood oxygenation (hypoxia)
Knowing your oxygen saturation can help you determine how your body is adapting to exercise, and stress.
If you suddenly see your oxygen level drop below 92% over multiple readings, it’s time to pay attention and alert your doctor.
Because low oxygen levels are often an early warning sign of disease, pulse oximeters are also a low-risk intervention that assists doctors and healthcare staff in diagnosing and treating many illnesses (like asthma, anemia, lung diseases and cancers, pneumonia, COPD, and emerging research for viruses like COVID-19).
Healthcare providers can also use it to check a person’s ability to handle increased activity levels, sleep apnea, post-surgery recovery, and rehabilitation and also to see how well your lungs are functioning.
Smartwatches and trackers that include oxygen sensors
While this article focuses on Garmin’s Vivosmart’s oxygen sensor, quite a few of Garmin’s smartwatches and some of its competitors also include a pulse oximeter.
- Garmin’s Fenix 6X and Fenix 5X Plus
- The Garmin Vivoactive 4
- Garmin’s Forerunner 245, 645, and 945
- Fitbit’s Ionic, Versa Lite, Charge 3 & 4, Versa 2, and Versa (2018 model and above)
- Fitbit tracks oxygen saturation only during sleep of 3 or more hours
- Withings Scanwatch (coming soon), Pulse, Pulse O2, Pulse Ox
How does Vivosmart Pulse Oximeter work?
The vívosmart device has a wrist-based pulse oximeter to gauge the saturation of oxygen in your blood.
Your device gauges your blood oxygen level by shining two frequencies of light, red and infrared into the skin, and checking how much light is absorbed to determine the percentage of hemoglobin in the blood that is saturated with oxygen.
This measure is referred to as SpO2.
The backside of your Vivosmart tracker has two LEDs that emit infrared and red light wavelengths.
When the user commands an SPO2 reading, the sensors emit light from these LEDs onto your skin. By measuring how much light passes through the blood, the sensor detects blood-oxygen levels. 
Oxygenated blood absorbs more infrared light, while deoxygenated blood allows more of it to pass through.
How to use the Vivosmart pulse oximeter feature to measure blood oxygen at the moment?
For the Garmin Vivosmart, you can measure your blood oxygen saturation while sleeping (3 hours +) and you can also manually measure your blood oxygen saturation at any time using the pulse oximeter widget.
When you manually test your blood oxygen, your device shows you an estimate of your peripheral blood oxygen saturation (SpO2%) for that moment in time.
Other Garmin models, like the Fenix, Forerunner, or Vivofit include options to measure and track your Pulse Ox automatically throughout the day (All-Day Pulse Oximeter readings) or night (Pulse Oximeter sleep tracking).
Get a Pulse Oximeter reading on your Garmin Vivosmart
- Wear the device above your wrist bone and make sure that it is snug but still comfortable.
- Garmin recommends you wear the band 2 finger-widths above your wrist for this reading. You can loosen it afterward so it’s everyday comfortable.
- Wrist-based heart rate sensors benefit from a snug fit for getting the most accurate readings!
- Press the ‘-‘ on the bottom of your Vivosmart
- Select the person icon with the heart symbol with the graph
- Tap the Pulse OX symbol (looks like an EKG)
- Lift your arm so it’s at heart level and stay still as the SPO2 sensor reads your oxygen level
- Vivosmart’s Pulse Oximeter displays your blood oxygen level as a percentage
Customizing pulse oximeter settings using the Garmin Connect app
You can customize settings via your Garmin Connect app to set up preferences for your pulse oximeter reading for sleeping.
The Vivosmart 4 lets you record up to four hours of pulse oximeter readings while you sleep.
Set up the pulse oximeter to track blood oxygen levels while you sleep
- Go to the settings menu in the Garmin Connect app
- Select Garmin Devices and choose your device
- Tap Activity Tracking > Pulse Ox
- Enable Pulse Ox Sleep Tracking
How to read Vivosmart pulse oximeter reading
Vivosmart and other Garmin trackers display your blood oxygen level as a percentage reading on the display of your device.
Any reading between 95% and 100% is normal and shows that your red blood cells are well oxygenated and sufficiently transport oxygen throughout your body.
Understanding the limitations of Pulse Oximeter in fitness bands
Pulse Ox readings from both wearables and finger pulse ox devices are less accurate when the wearer is moving, making them much less useful for continuous monitoring of healthy, mobile users.
A Fitbit rep said that the Estimated Oxygen Variation chart seen in its app is “not intended to track slow fluctuations in relative SpO2 or sustained hypoxia as might occur with acute or chronic respiratory problems.”
Similarly, Garmin’s UK head of product, Rich Robinson said in a recent interview to Wired that “the SpO2 sensors on its Fenix adventure watches are precise enough to help users to train and make decisions at high altitude in mountainous regions, where oxygen saturation can drop, but they are categorically not designed for medical use:
“To a certain extent, it is accurate but there’s a whole host of variables, whether you’ve got the device fitted correctly or are you moving while you’re trying to take the reading?”
How accurate are the Vivosmart’s Pulse Oximeter and Garmin’s Pulse Ox feature?
When it comes to Vivosmart pulse oximeter accuracy, Garmin is very clear.
While every effort is made to ensure a high degree of accuracy, there are certain limitations that can cause inaccurate measurements.
The user’s physical characteristics, fit of the device, and presence of ambient light may impact the readings.
The Pulse Ox data is not intended to be used for medical purposes, nor is it intended to diagnose, treat, cure, or prevent any disease or condition.
The company clearly spells it out on its site that Garmin wearables are not medical devices, and the data provided by them is not intended to be utilized for medical purposes and is not intended to diagnose, treat, cure, or prevent any disease.
Garmin recommends you consult your doctor before engaging in any exercise routine.
That said if you consistently see results in the 95-100% range, your blood saturation is all likelihood good.
However, if your Vivosmart or other Garmin (or another brand) device consistently shows multiple readings below 92% at different times of the day and on different days, it’s time to contact your healthcare provider.
Let them know you see these concerning results on your wearable device and ask them to test your device’s results against their medical pulse oximeters.
Vivosmart Blood Oxygen readings not working? Check these tips
If the pulse oximeter data is erratic or does not appear, follow these Garmin tips and give it a try.
- Use your device to measure your oxygen level in the blood when you are at rest
- Given the position of the sensor, inspect the back of your Garmin for any accumulated dirt or residue from regular wear
- Clean the device with a dry or slightly damp microfiber cloth–you can use water, 70% isopropyl alcohol, or a Clorox disinfecting wipe–do not use bleach!
- If needed, use a soft-bristled toothbrush (like a surgical toothbrush) or interdental brush to clean dirt and debris away from charging contact points or any cavities.
- Clean the device with a dry or slightly damp microfiber cloth–you can use water, 70% isopropyl alcohol, or a Clorox disinfecting wipe–do not use bleach!
- You must remain motionless in order to get the best oxygen saturation reading. Research has shown this as one of the most important factors when trying to get accurate SpO2 readings.
- Check if the device is snug yet comfortable.
- Hold the arm wearing the device at heart level while the device reads your blood oxygen saturation.
- Check that there are no scratches or damage to the optical sensors on the back of the device.
Lastly, make sure you are not using sunscreen, lotion, or insect repellant on your skin under the device. That can cause issues with getting accurate blood oxygen readings.
References:
It appears that the Vivosmart 4 records oxygen level every minute for four hours while sleeping.
That being said, what does it mean when minutes are skipped? For instance, I place my finger on the ox chart and it shows the time taken but last night it skipped three minutes before recording the next ox. This has happened more than once.
Hi Sarah,
Skipped minutes could be due to your body’s movement or even sleeping in an unusual position that disrupts a reading. It isn’t that unusual to see skipped minutes here and there.
Remember that your Garmin Vivosmart 4 takes a measurement of your blood oxygen level for up to 4 hours each time you sleep–it cannot take a measurement for your full night’s sleep.
The accuracy of Garmin’s SPo2 sensor is suspect. I am consistently reading 90% with my Garmin where my fingertip pulse ox is reading 96% or 97%.