How to save $400+ on a new Series 6 Apple Watch: Get a $20 pulse-ox sensor from Amazon

Is the new pulse oximetry health sensor on the Series 6 Apple Watch worth the spend? We look at a very inexpensive alternative, as well as some reasons it might be worth forking over your hard-earned cash for a new Watch upgrade.
Written by David Gewirtz, Senior Contributing Editor

Let's get the disclaimer out of the way first: I'm not a doctor. Nothing I'm going to tell you is backed by any medical training. You should definitely see your doctor before making any decisions, especially based on the information I tell you.

Also: Everything Apple announced at Sept. 15 event

OK, so now that that's out of the way, let's discuss the two breathing-related features introduced at Apple's Time Flies event: VO2 Max and SpO2. It looks like VO2 Max will be available for any Apple Watch with a heart rate sensor, while the new SpO2 feature is limited to the Apple Watch Series 6 announced today.

VO2 Max

According to the University of Virginia School of Medicine:

VO2 max, or maximal oxygen consumption, refers to the maximum amount of oxygen that an individual can utilize during intense or maximal exercise. This measurement is generally considered the best indicator of cardiovascular fitness and aerobic endurance.

Apple will start tracking VO2 Max data as part of WatchOS 7. Later in the year, Apple will also start tracking the bottom end of VO2 data, which can help flag potential health risks.


Once again, according to Johns Hopkins Medicine:

Pulse oximetry is a test used to measure the oxygen level (oxygen saturation) of the blood. It is an easy, painless measure of how well oxygen is being sent to parts of your body furthest from your heart, such as the arms and legs.

For people with heart or lung conditions, COPD, asthma, and a host of other medical conditions, it's important to keep an eye on your SpO2 levels. The Apple Watch Series 6 adds sensors that allow the Watch to gather SpO2 information in real-time, right on your wrist.

The $20 alternative

I have an Apple Watch Series 4, which I quite like. I also regularly measure my blood oxygen saturation levels. But I don't intend to replace my current Watch with a $400-or-more Series 6 just to get the SpO2 sensor.

That's because I have a $16.95 pulse oximeter that I bought from Amazon. I place this little guy on a finger, and within about 10 seconds or so, it presents me with my SpO2 reading. The batteries on mine have lasted a full year, so far.

Also: Apple Watch: New or refurbished? Why I'm glad I bought a used Series 4

Sure, it's a separate device. But it's also not another $400+. Since I have an Apple Watch with a 44mm screen and cellular service, replacing my Apple Watch would cost me $529. I'll stick with the separate device.

When buying a Series 6 Watch makes sense

That's not to say you shouldn't buy a Series 6 Apple Watch. First, if you don't have an Apple Watch, the new SpO2 feature effectively comes for free, since the price of the watch didn't go up year over year. I'm just saying you probably don't need to rush out and replace your existing Series 4 or Series 5 watch with the new Series 6.

I am intrigued by the SpO2 feature of the Series 6 Apple Watch because it does do things my inexpensive pulse-ox doesn't. The most important is that the Watch logs your measurements. That way, you can keep track of all your numbers without having to transcribe data onto a notepad or something.

It also captures regular measurements. This might be useful for you or your doctor to review later. Let's say you work in an office building and while you're at work, your O2 stats go down, but when you're at home or on the road, the stats go up. That data might mean something.

Also, there may be some strong benefits for early detection of coronavirus, especially if you're out and about regularly or need to be around people.

Falling O2 numbers may indicate all sorts of breathing or lung-related issues, including those associated with early stages of the coronavirus. Unfortunately, as Science Magazine reports, most people don't notice those low levels.

Given that the new Apple Watch Series 6 can deliver alerts when SpO2 levels drop, it might be possible for the new Watch to provide early COVID-19 warnings for otherwise asymptomatic patients.

Another COVID-related benefit of the wrist-borne version of the SpO2 sensor is that it doesn't involve touching with fingers. The typical pulse oximeter needs to be placed on a finger, which might have also touched a contaminated surface. But by keeping the readings on the wrist, that additional potential fomite contact pathway is all but eliminated. Yes, you do need to touch the watch to initiate an action, but you don't need to in order to get alerts.

If you're working with the elderly or kids who are uncooperative when it comes to keeping a finger sensor on a hand -- especially if it needs to be there for an extended period -- the Series 6 version could be a huge help both in terms of increased comfort and increased compliance.

Also: Apple is adding sleep tracking to Apple Watch, but what about the battery life?

Finally, I would think the ability to do real-time blood oxygen monitoring might prove a real boon to tracking sleep apnea, but Apple made no mention of sleep apnea. This was surprising because they have two main measurement components: A sleep tracker and a SpO2 monitor. My guess is that there hasn't been FDA approval of code for sleep apnea monitoring, and we'll probably see the feature announced next year.

Bottom-line it for me, David

So, what's the bottom line? Are the pulmonology-related features of Apple Watch Series 6 worth dumping a Series 4 or 5?

That, of course, is up to you. Look at the various logging and real-time benefits I described above and decide if you need them. If not, you can always pick up an inexpensive pulse-ox now and upgrade to the Series 7 or Series 8 when they come out.

And, remember, check with your doctor before following any of the recommendations I've outlined in this article.

You can follow my day-to-day project updates on social media. Be sure to follow me on Twitter at @DavidGewirtz, on Facebook at Facebook.com/DavidGewirtz, on Instagram at Instagram.com/DavidGewirtz, and on YouTube at YouTube.com/DavidGewirtzTV.

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