You don't need the fanciest watch. You need one that fits how you actually move, so it gives you a number you can retest every 90 days.
How we make money: the "Affiliate placeholder" cards below link straight to each maker's official page. None of them are affiliate links yet. If we join a program later, we'll label those links "(paid link)" and it won't change which watches we pick. Affiliate disclosure.
This matters more after 40 than any spec sheet. Garmin's and COROS's VO2 max estimates on the watches below come from outdoor runs (Garmin also counts trail runs).811 Garmin's manual asks for at least 10 minutes outdoors at 70% or more of your max heart rate.12 If you don't run, you may never get a fresh number.
Apple Watch estimates from outdoor walks, runs and hikes.3 Polar's Ignite 3 has a dedicated 30-minute Walking Test.56 For a lot of people over 40, that's the difference between a number you can track and one you can't.
| Watch | How it estimates VO2 max | From walking? | Maker's price* |
|---|---|---|---|
| Apple Watch Series 12 or SE 3 | Outdoor Walk, Outdoor Run or Hiking workouts | Yes | From $229 (SE 3) / $399 (Series 12) |
| Polar Ignite 3 | 30-min Walking Test, 5-min resting Fitness Test, Running Index on runs | Yes (Walking Test) | $399.99 |
| Garmin Forerunner 170 | Outdoor runs and trail runs | Not listed | $299.99 |
| COROS PACE 4 | Outdoor runs (pace + heart rate) | Not listed | From $249 |
| Garmin Forerunner 570 | Outdoor runs and trail runs | Not listed | $549.99 |
| Garmin Venu 4 | Outdoor runs and trail runs | Not listed | From $549.99 |
| Garmin fēnix 8 | Outdoor runs and trail runs | Not listed | From $999.99 |
*US list prices shown on garmin.com, polar.com, coros.com and apple.com on Oct 20, 2026. Prices change and sales are common, so check the maker's page. "Not listed" means the maker's spec sheet lists VO2 max for running and trail running only.
Best for: iPhone users who mostly walk or hike
Estimates "Cardio Fitness" (VO2 max) from outdoor walks, runs and hikes, so you don't have to run. Lets you note heart-rate-lowering medications in the Health app. Needs an iPhone 11 or later.
From $229 (SE 3) / $399 (Series 12) on the maker's site
See Apple Watch →Links to the maker's official page · not an affiliate link yet · if that changes we'll label it. Disclosure.
Best for: Walkers who want a set test to repeat
Three ways to estimate: a 30-minute Walking Test on a flat ~2 km route, a 5-minute lying-down Fitness Test, and Running Index after runs of 12+ minutes. The Walking Test is easy to repeat every 90 days.
$399.99 on the maker's site
See Ignite 3 →Links to the maker's official page · not an affiliate link yet · if that changes we'll label it. Disclosure.
Best for: Runners on a budget who want Garmin
Garmin's entry-level runner's watch. VO2 max from outdoor runs and trail runs, plus fitness age, training load and recovery time. Up to 10 days of battery in smartwatch mode.
$299.99 on the maker's site
See Forerunner 170 →Links to the maker's official page · not an affiliate link yet · if that changes we'll label it. Disclosure.
Best for: Lowest price for a dedicated running watch
A light AMOLED running watch. COROS estimates VO2 max from your outdoor runs and updates it over time, alongside its Running Fitness score and lactate threshold.
From $249 on the maker's site
See PACE 4 →Links to the maker's official page · not an affiliate link yet · if that changes we'll label it. Disclosure.
Best for: Regular runners who want more coaching
Two sizes (42 and 47 mm). VO2 max from runs and trail runs, with heat and altitude acclimation, fitness age and Garmin Coach training plans. Up to 11 days of battery in smartwatch mode.
$549.99 on the maker's site
See Forerunner 570 →Links to the maker's official page · not an affiliate link yet · if that changes we'll label it. Disclosure.
Best for: An everyday health watch that also runs
More lifestyle and health-tracking than training-focused, in 41 or 45 mm. VO2 max from runs and trail runs, plus fitness age. Up to 12 days of battery in smartwatch mode.
From $549.99 on the maker's site
See Venu 4 →Links to the maker's official page · not an affiliate link yet · if that changes we'll label it. Disclosure.
Best for: Hikers and ruckers who want maps and long battery
Rugged, premium and expensive. Built-in maps, an LED flashlight, endurance score and real-time stamina, with VO2 max from runs and trail runs. Up to 29 days of battery (51 mm AMOLED).
From $999.99 on the maker's site
See fēnix 8 →Links to the maker's official page · not an affiliate link yet · if that changes we'll label it. Disclosure.
No watch matches a lab test, and the differences between brands are smaller than the error within any one brand. A 2022 meta-analysis found exercise-based estimates were close on average but could be about 10 mL/kg/min off for an individual.1 In a 12-week training study, Garmin and Polar estimates didn't pick up real lab-measured gains.2 We cover the brand-by-brand evidence in How accurate is your watch's VO2 max estimate?.
The practical upshot: pick the watch you'll wear and use the same way every time. Consistency beats a fancier sensor.
WHOOP is a screenless strap, not a watch. It now estimates VO2 max from all-day and overnight data, plus GPS-tracked outdoor runs, and you can anchor it to a lab result. Its published accuracy figures come from the company's own testing, not an independent study yet.14 It's a reasonable option if you'd rather not wear a watch and don't mind a membership.
Enter your watch's reading in our VO2 max calculator to see your approximate percentile for your age and sex. You can also browse the men 50–59, women 50–59 and all norms by age. Then use these simple ways to move it up.
Not a diagnosis. Strong After 40 compares your numbers to published population norms for education and motivation only. It is not medical advice. Consult your doctor before starting a new exercise program or doing maximal-effort tests, especially if you have heart, joint, or other health conditions. Full disclaimer
Product mentions aren't medical advice or an endorsement for your situation. We didn't receive free products or payment for this page.