You no longer need a lab test to get a reasonable estimate of your VO2 max. Modern wearables use heart rate, pace, and sophisticated algorithms to estimate cardiorespiratory fitness directly from your wrist.

What to look for in a VO2 max wearable

Before diving into brands, consider these key features:

• Reliable heart rate sensor – Optical sensors are convenient, but pairing with a chest strap improves accuracy.
• GPS tracking – Essential for accurate pace and distance during runs and rides.
• VO2 max estimation – Look for devices that report VO2 max or “cardio fitness” directly.
• Battery life – Make sure it lasts long enough for your longest sessions.
• Training features – Heart rate zones, training load, and recovery metrics are a bonus.

Garmin devices

Garmin is a favorite among runners and triathletes:

• Garmin Forerunner series – Watches like the Forerunner 255 or 965 provide VO2 max estimates, training status, and race predictions.
• Garmin Fenix and Epix – Premium multisport watches with robust navigation and fitness tracking.

Garmin uses Firstbeat analytics to estimate VO2 max from steady-state runs and rides when GPS and heart rate data are good.

Apple Watch

The Apple Watch focuses on overall health and everyday wear:

• Provides a “cardio fitness” score linked to VO2 max for outdoor walking and running.
• Offers ECG, heart rate alerts, and integration with Apple Health.
• Works well for those who want a smartwatch first and a fitness tracker second.

Look for versions like the Apple Watch Series or Ultra models for the most robust fitness features.

Polar watches

Polar has a long history in heart rate and endurance training:

• Devices like the Polar Grit X or Polar Pacer Pro estimate VO2 max and offer detailed training load metrics.
• Polar’s Fitness Test can estimate VO2 max even at rest using heart rate and variability.

Other notable options

• Coros – Lightweight, long-battery watches that provide VO2 max estimates, especially popular with trail and ultra runners.
• Fitbit – Some models provide “cardio fitness level” based on VO2 max estimates, targeted more at general health than performance training.

You can explore a range of VO2 max–enabled fitness watches to find one that fits your budget and style.

Heart rate straps and accessories

For improved accuracy:

• Pair your watch with a chest-strap heart rate monitor for more stable readings.
• Consider cycling power meters or smart trainers if you’re a cyclist who wants precise power data alongside VO2 estimates.

How accurate are VO2 max estimates?

Consumer wearables give estimates, not clinical measurements:

• They are typically within a reasonable range (often within 10–15%) for many users.
• Accuracy improves with consistent use, good GPS signals, and clean heart rate data.
• The most valuable aspect is the trend over time, not the exact number on day one.

The bottom line

Garmin, Apple, Polar, and other brands offer powerful tools for tracking VO2 max and overall fitness without stepping into a lab. Choose a device that fits your sport, budget, and lifestyle, pair it with good training habits, and use VO2 max as one of several metrics guiding your progress.

References / Sources

Cleveland Clinic – VO2 Max & Testing
Apple – Cardio Fitness (VO2 Max) Info
Garmin – VO2 Max Explained