3 Best Wearables for Life Extension in 2021

3 Best Wearables for Life Extension in 2021

Affiliate Disclaimer: Longevity Advice is reader-supported. When you buy something using links on our site, we may earn a few bucks.

I came to the human life extension community not as a spanner (initially), biohacker, or a young person filled with existential dread, but as a person obsessed with quantified self. As a teen, I used pencil and paper to track my sleep and my food intake. As a college student, I wore a pedometer and tracked my daily steps on a spreadsheet. In 2014, Fitbit released the Fitbit Force, and since then I’ve had some version of top wearable on my wrist, continuously tracking what I do. 

The feedback I’ve gotten from these devices is exceptional. I know that I gain, on average, 1.7 pounds before every menstrual cycle, and that I lose that weight about a day before it’s finished. I know that I need about seven hours and 40 minutes of sleep every night to feel well-rested. I know that if I get at least 40 minutes of cardio on one day, the following day my resting heart rate is a beat or two lower than my overall average. Knowing my body this well puts me in a great place to know if something is going wrong, if I need to reconfigure my lifestyle to push my metrics in the right direction.

This past year, my beloved Fitbit Ionic died (it didn’t survive an eight-foot-deep pool, even though it really should have). Panic emerged. I hadn’t prepared to replace my wearable in 2020, and with so many options on the market, I wasn’t ready to commit to another Fitbit just because I had owned several in the past. 

I wanted the best wearable with the best data with the most actionable feedback I could find. After all, I’m a spanner. I want to use this data for something pretty important: living a really long time.

The best wearables for life extension

So I broke out the spreadsheet and started my research. What are the best wearables for life extension—not just for me, but for anybody? I decided that the following variables were important:

  • The best wearable must continuously gather actionable, useful data, regardless of interaction from the user (e.g.: automatically tracks sleep stages and continuously monitor heart rate)
  • The best wearable must have proven their data accuracy in a clinical setting
  • The best wearable must sync with common health apps (without bandaids like IFTTT)

From there, I developed a comprehensive list of about 25 wearables—and found that there were categories that I hadn’t previously considered, like sleep wearables. I broke down my research further: I wanted to find the best wearables for longevity overall, (including smartwatches, headbands, and rings), the best heart rate monitor chest strap, and the best continuous glucose monitor. I slowly narrowed down the list, feature by feature, tie-breaking by price when I had to. 

One wearable emerged victorious over the others in each of the three categories. I’m including the runners-up for context and to provide an alternative if you’re not convinced by my top pick. 

Best Wearable for Radical Life Extension Overall

1. Polar Vantage V2

Price: $499

The Polar Vantage V2 is one of the best wearables in 2021 for life and healthspan extension. Image of the Polar Vantage V2 on a cyclist.
The Polar Vantage V2 is the best wearable for spanners in 2021. Source

It should come as no surprise that a super rugged, feature-dense, made-for-athletes sports watch climbed to the top of this best wearables list. 

The Polar Vantage V2 is not for people who want to skimp on their workouts. It’s a smartwatch that was created for ultrarunners and triathletes; it offers military-grade hardware, a 52-gram lightweight body (it weighs a little more than two silver dollars), and a color touch display. 

But enough about how tough it is and what it looks like; let’s talk about the kind of data that you can get from it. 

polar vantage longevity wearable data
The Polar Vantage V2 data output. Source

It’s almost unfair to compare the Polar Vantage V2 to other wearables because of just how much data it can accurately collect and analyze

For example, the WHOOP strap 3.0 is really good at one thing: measuring recovery. It looks at your Heart Rate Variability (HRV), Resting Heart Rate (RHR), respiratory rate, and sleep metrics (making it a top sleep tracker for longevity in 2021) to spit out a daily “Readiness Score.” Polar Vantage V2 offers the exact same features as part of its overall suite… and it doesn’t mince on other basics, like steps, calorie counting, VO2max, and stress measurements also found in smartwatches like the Fitbit Sense and the Apple Watch Series 6. And, like many of the other brands mentioned here, Polar has an extensive research library of peer-reviewed studies to back up the accuracy of their sensors—not just the Polar Vantage V2, but their entire suite of products.  

In other words, Polar certainly has all the basics that you’d expect to find in a top wearable. Where it excels is in the advanced data gathering that you can’t find in other commercial products.

For example (and especially for keto enthusiasts), Polar Vantage V2 will break out your calorie expenditure by macros: it will estimate, from your workout data and body composition, the distribution of how many carbs, fats, and proteins you used for fuel during the workout’s duration. And remember, this watch was made for endurance athletes, so you can set it to nudge you to eat a carb or hydrate if you’ve lost track of time on a long run.

The top wearable Polar Vantage V2 calculating calorie expenditure.
Calculating burned carbs, fats, and proteins with Polar Vantage V2. Source

If you’re looking to gather information about your muscle and cardio load during a strenuous workout, the Polar Vantage V2 also calculates your training load level based on your heart rate data. It’ll let you know how much strain you’re putting on your cardiovascular system. It also records your “muscle load.” Polar explains:

Muscle load shows the amount of mechanical energy (kJ) that you produced during a running or cycling session. This reflects your energy output (instead of the energy input it took you to produce that effort). In general, the fitter you are, the better the efficiency between your energy input and output. Muscle Load is calculated from your power data, so you only get a Muscle Load value for your running workouts (and cycling sessions if you’re using a cycling power meter).

The tracker also accepts inputs for your rate of perceived exertion.

Who is the Polar Vantage V2 not for?

Here’s the thing: most people don’t need all of the Polar Vantage V2’s advanced tracking features. While I imagine most spanners do work out regularly, the Polar Vantage V2’s metrics might be overkill for someone who works out a half-hour at a time a handful of times a week. Many of the device’s more advanced measurements (like calorie expenditure) are based on equations over advanced sensors, so while the user may appear to get more information, they’re just learning more about themselves from algorithms other tools haven’t bothered with. 

If you’re looking for a slightly more affordable option, I’d recommend the Apple Watch Series 6, the WHOOP Strap 3.0, and the Fitbit Sense with Premium, depending on your existing digital ecosystem. 

Best Heart Rate Monitor Chest Strap

Why might someone want a chest strap heart rate monitor in addition to an optical heart rate monitor on a smart watch? 
In 2019, a team of researchers set out to test the accuracy of chest strap heart rate monitors and fitness bands. While the chest strap heart rate monitor matched an ECG’s reading 98% of the time, fitness bands didn’t line up nearly as well (except, notably, the Apple Watch III, which was aligned 96% of the time). If you’re worried about your heart rate data getting messed up from a sweaty wrist, a misplaced band, or an inaccurate wrist device, consider a chest strap.

2. Polar H10

Price: $99.95
Polar H10 is considered the standard in the industry—the study mentioned above used the Polar H7 to benchmark chest strap heart rate accuracy, and a more recent analysis concluded that the Polar H10 is 99.7% aligned with ECGs. And that’s the biggest selling point for the Polar H10: it’s ridiculously accurate.

Top chest heart rate tracker in 2021 Orthostatic test
Like stats? Polar gives you stats. Source

Everything else about the chest heart rate monitor is window dressing. It can pair up to two devices at once over Bluetooth and it offers ANT+ connectivity. If you have the Polar Vantage V2, you can run regular Orthostatic tests, which give you feedback about your cardiovascular fitness and recovery over time. 

Looking for an alternative? Check out the Wahoo Tickr X, which some reviewers say is a little more comfortable to wear over a long period of time.

Best Continuous Glucose Monitor

The longer you’re in the life-extension space, the more you’ll hear about the dangers of sugar. Longevity influencer Dr. Aubrey de Grey argues that avoiding a sedentary lifestyle and sugar are starting points for any spanner. Dr. Peter Attia dedicates an inordinate amount of time educating his audience on insulin resistance. And Dr. Rhonda Patrick is obsessed with glucose regulation… so much so that she famously wears the continuous glucose monitor (CGM) that we recommend in this guide. 

While more research is certainly needed, there have been a handful of studies that show that both random glucose and a high mean fasting glucose correlate with all-cause mortality (in the general population and among Korean adults, respectively). Learning about your daily glucose fluctuations can, at least theoretically, help guide you to avoid certain foods and engage in healthier behaviors. It’s worth nothing that while it may seem intuitive, using a CGM for behavior change has never been proven in a clinical setting. 

Again, while looking for the best continuous glucose monitor in 2021, I sought out the option that gave the highest quality, actionable data. Discerning how to rank glucose monitors was tough—in the U.S., most continuous glucose monitors are available by prescription only. While I’m sure there are plenty of spanners who have Type I and Type II diabetes, I did go back and forth on including a by-prescription-only option on this list for accessibility purposes. I decided to include the prescription model because of its accuracy, and then offer an alternative for people who can’t get access to the Dexcom G6.

3. Dexcom G6

Price: Around $370, according to GoodRx

Compared to competitors like the FreeStyle Libre and the Medtronic Guardian Connect, the Dexcom G6 offers the most features. It has a compatible Android and iOS app, it can provide accurate readings (even with acetaminophen), and provides automatic glucose-data sharing. Clinical trials studying both adults and children show that the Dexcom G6 is a highly accurate glucose monitor. 

The Dexcom G6 syncs with Dexcom CLARITY Diabetes Management Software. CLARITY uses the data from your monitor to detect patterns, see how long you stay within defined ranges, and detect hypo- or hyperglycemia, regardless of if you have a formal diabetes diagnosis. 

best wearables for life extension dexcom g6 data
Dexcom CLARITY patterns from Dexcom G6. Source

The Dexcom G6 data can also sync with some of the other best wearables that you might already be using, including Fitbit and Apple watches. 

Ask your doctor nicely for a prescription for the Dexcom G6 if you don’t have diabetes—there are several blog posts from biohackers claiming that their physicians have few qualms about writing a script, especially if it’s for preventative care. Note that many insurance companies will not cover a Dexcom G6 if you don’t have diabetes. 

If your doctor is unwilling to write a script, you might want to check out Levels Health. 

Levels Health

Price: Not listed on website

Levels Health is also only available by prescription, but unlike the Dexcom G6, you don’t need diabetes to gain access to it. Levels Health aligns you with an in-state physician who asks you “a series of questions” (it’s unclear what those questions are) before writing you a script. 

From there, you wear your Levels Health continuous glucose monitor and log your foods. Part of the service includes chatting with Levels specialists to determine what’s working, what isn’t, and how you can optimize your diet.

Levels continuous glucose monitor as one of the best wearables in 2021
Feedback from Levels Health. Source

The trouble with Levels Health is that I couldn’t find any clinical trials to validate the accuracy of their sensor. The company is also so new that there aren’t any integrated apps for its data other than their own. I imagine that anyone interested in Levels Health would be someone with the mindset that more data is probably better than less, that physician-guided quantified self is worthwhile, and that continuous glucose monitoring is worth jumping through all the hoops to gain access to it. 

Are these really the best wearables for life extension?

I know that there are several top wearables that are particularly popular among spanners that aren’t mentioned here. Those include the Oura Ring (good for sleep analytics), WHOOP Strap 3.0 (good for recovery analytics), and Apple Watch Series 6, Garmin Vivosmart 4, and Fitbit Sense (all good for lifestyle health metrics). It’s worth underscoring that all of these are worthwhile wearables, especially if you aren’t a regular endurance athlete. 

I’m curious about which of these best wearables you’re using. Do you use any of the ones mentioned above? How do you make use of the data to live longer? Let me know your thoughts in the comments below.


  1. Pingback: 8 Best Sleep Trackers and Apps for Longevity in 2021 - Longevity Advice

  2. brent

    I have the Oura ring and Apple Watch 6 and love the metrics from both. I have started looking more into wearables that effect change. I have been wearing the Apollo Neuro for a couple of months and have noticed a significant change in HRV.

  3. Pingback: Quantified Self for Longevity: The Ultimate Guide - Longevity Advice

  4. Pingback: 5 Best Nutrition Tracker Apps for 2021 - Longevity Advice

  5. Max

    Hi Rachel – great article!

    Did you consider any of the Garmin watches while doing your research? Those are cropping up quite a bit in my research, curious as to A) whether they came across your radar, and if so B) what their major disqualifying factors were (low accuracy? not enough peer-reviewed lit?).


    1. Rachel Burger

      Hey Max!

      Great question. I actually think Garmin is great—Polar just spits out more health data than lifestyle watches (Fitbit/Apple Watch etc). If you’re not a professional athlete, lifestyle watches really are all you need.

      In particular, I like the Garmin vívosmart® 4. It has an excellent battery life and has plenty of accuracy research behind it (and it’s moderately good at sleep stage tracking—something most smart watches struggle with). Plus it’s relatively cheap ($129?) so there’s not a massive barrier to entry.

      I’ll also add that the Garmin Fenix 6 Pro is a great direct competitor to the Vantage V2—it only falls short on every day heart rate monitoring. It’s also slightly pricier, but if you’re a big hiker you’ll probably appreciate its GPS capabilities over the V2.

      I hope that helps!

  6. Pingback: What Longevity Diet do Experts Eat? - Longevity Advice

  7. Pingback: 7 Best Life Extension Blood Tests and Companies in 2024

Leave a Reply

Your email address will not be published. Required fields are marked *