One of the best mid-range sports watches I've tested isn't made by Garmin or Amazfit

ZDNET's key takeaways

The Polar Vantage M3 has all the software features of its more expensive older siblings, but is available in two color options for just $400. The watch is affordable, has a lovely AMOLED, performs well, and appeals to those with smaller wrists. Rugged durability is not a focus of the watch, and the smartwatch features are limited.

We are approaching the tail end of the fall marathon season, but I just spent a few weeks running in Washington, Maine, Rhode Island, and Maryland and saw hundreds of runners out on the local roads and trails. Many runners also participate in other activities to help build strength and prevent injury, so having a watch that supports multiple activities is important for them.

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Polar excels at offering free training programs that mix various activities with running to help you achieve the best results. I've taken the new Polar Vantage M3 out for the past few weeks, and it is clear that Polar did well at launching an affordable multi-sport watch that includes its superb performance and recovery tools from its flagship models, like the Vantage V3 and Grit X2 Pro.

Since I have larger wrists and love big watches, those two other Polar watches are best for me. That said, the Vantage M3's smaller size and lower price will appeal to more people.

We've seen Garmin, Coros, and Suunto recently release watches in the mid-range market as well, so this space is heating up. Polar is clearly focused on serving as your advanced training tool, not just acting like a smartwatch. It has limited notification support, no third-party application support, no wrist-based payments, and no offline music support.

That said, it has advanced training tools, recovery guidance, performance tests, advanced sleep tracking with skin temperature sensors, and offline maps for navigation that look great with the brilliant 1.28-inch AMOLED touchscreen. Weighing just 53 grams, which includes the band, the watch is very comfortable for wearing 24/7 and in my experience, you can expect it to last about a week if you run 30 to 45 minutes every few days.

Also: Why I wear this $180 smartwatch even after testing Garmin and Samsung watches

Polar advertises 30 hours of the best GPS tracking mode with seven days of smartwatch mode. Over the past month, I charged it up every five to seven days.

Dual-frequency GPS and five GNSS options are available, with test results showing very accurate location tracking. The fourth-generation optical heart rate sensor closely matched the results from other watches and the arm band sensor I compared it with while running, biking, rowing, and walking.

Once you determine that the Polar Vantage M3 is the right fit for your budget and wrist, explore the vast Polar Flow ecosystem. There is a Polar Flow smartphone app for iOS and Android, along with a website. I highly recommend that you do not limit your experience to just the app -- the app provides glanceable information and some details of your activities, but the website is where you can go to dive into all the details of the vast amount of data the Vantage M3 collects.

While there are custom running programs for typical running events, you can also use the season planner to create custom programs for off season running. The various strength, stretching, and cross-training elements that you can include in these programs is fantastic. I've learned many new stretches and exercises thanks to Polar Flow, and love that the programs are not limited just to different sessions of running.

Also: I walked over 10,000 steps with 3 sports watches - this one was the most accurate by far

Smartwatches, like the Apple Watch, have fairly limited data screens for your activities, so you can only view the key metrics Apple wants you to see. Open up each of your favorite activities, labeled sports profiles, in the smartphone app or website and then fully customize each of the data screens.

You can have up to eight screens, with up to four metrics on each screen. These include rather unique metrics such as incline/decline, body temperature, power metrics, and cadence metrics. There are several other views and settings to completely customize and optimize your activity view. The Vantage M3 has more than 150 activities you can participate in and track.

Once you have your sports profiles set up, Polar's Training Load Pro kicks in to evaluate the recorded data and your daily life metrics for recovery. After three nights of wearing your Vantage M3 to bed, you will begin to see sleep tracking results. In addition to your sleep details and nightly skin temperature (good for indicating possible illness), Polar provides a Boost from Sleep metric that shows how your sleep affects your energy levels throughout the day.

Also: This Garmin beat my Apple Watch Ultra in almost every way (and it's just as rugged)

In the past, I rarely used the mapping and navigation features on my watches, but Strava heat maps have proven to be an amazing function when I travel, and it has also prompted me to add new routes to my typical running routine. After selecting my preferred distance and finding a route that interests me on Strava, I simply save the route, which gets synced to my Polar Flow account and then to the Vantage M3. It is easy to then start a run and have full color mapping guide me on unique routes in various cities.

ZDNET's buying advice

Polar has taken the software features of its best watches and brought them to the masses with the Polar Vantage M3. You can now choose a smaller, lighter, more affordable Polar watch and enjoy the same advanced functions and options that are in the company's flagship watches. It's great to be able to choose a watch based on the size, style, materials, and design that works best for you, while trusting that the software experience will be the same as a watch priced almost twice as high.