The Polar Vantage M3 and Garmin Forerunner 265 are two AMOLED GPS running watches aimed at runners who want training insights without stepping into flagship pricing. At $399.99 for the Polar and $449.99 for the Garmin, both weigh 47g, but they differ in battery life, training features, and ecosystem strengths.
| Feature | Polar Vantage M3 | Garmin Forerunner 265 |
|---|---|---|
| Price | $399.99 | $449.99 |
| Display | AMOLED touchscreen | AMOLED touchscreen |
| Battery (Smartwatch Mode) | Up to 30 hours (training mode), several days (watch mode) | 13–15 days |
| Battery (GPS Mode) | Up to 30 hours (continuous GPS) | 20–24 hours (GPS-only) |
| GPS | Built-in GPS/GNSS | Multi-band GNSS |
| Weight | 47g | 47g |
💡 Pricing and specs reflect manufacturer-listed figures as of 2026-06-14 and may vary by retailer, region, or firmware updates.
Why Choose Each Watch
Polar Vantage M3
- Training Load Pro splits cardio, muscle, and perceived load
- Recovery Pro measures autonomic nervous system every morning
- Strong value marathon-training tool in its price range
- Smaller running-focused community/content vs. Garmin or Coros
- Battery life specs are less class-leading than Coros
Garmin Forerunner 265
- Vibrant always-on AMOLED display
- Advanced training metrics: VO2 max, training readiness, HRV status
- Music storage and contactless payments
- Shorter battery life than Coros equivalents
- No onboard maps (route line only)
Verdict
For marathon-focused runners who want strong training and recovery guidance at a lower price, Polar Vantage M3 is the better pick because it costs $399.99 versus $449.99 and adds Polar’s Training Load Pro and Recovery Pro, while still offering up to 30 hours of continuous GPS. For runners who want a brighter smartwatch-style experience and more lifestyle features, Garmin Forerunner 265 is the better pick because it includes advanced metrics like VO2 max, training readiness, and HRV status, plus music storage and contactless payments, all at the same 47g weight.
FAQ
Which has better battery life, Polar Vantage M3 or Garmin Forerunner 265?
It depends on how you use it. The Polar Vantage M3 is rated for up to 30 hours in continuous GPS/training mode, while the Garmin Forerunner 265 is rated for 20–24 hours in GPS-only mode. In smartwatch use, Garmin lasts longer at 13–15 days, whereas Polar is described more generally as lasting several days.
Is the Polar Vantage M3 worth buying over the Garmin Forerunner 265 for marathon training?
For many marathon runners, yes. The Polar Vantage M3 costs $399.99, which is $50 less than the Garmin Forerunner 265 at $449.99, and its Training Load Pro and Recovery Pro are specifically useful for managing cardio load, muscle load, perceived effort, and morning recovery. It also offers up to 30 hours of GPS use, which is helpful for long training sessions.
Should I get the Garmin Forerunner 265 instead of the Polar Vantage M3 if I want more smartwatch features?
Yes, the Garmin Forerunner 265 is the stronger choice if smartwatch features matter more. It has an AMOLED touchscreen like the Polar, but adds music storage and contactless payments, along with advanced metrics such as VO2 max, training readiness, and HRV status. It also matches the Polar at 47g, so you are not paying a weight penalty for those extra features.