Polar A370
Polar A370

Polar A370 Review

In this Polar A370 review we present to you an alternative to the already available A360 from Polar, the A370. New features include a dynamic 24/7 heart rate measurement on the wrist for the very first time, as well as a more detailed breakdown of sleep phases, including feedback, read more about it.

You can buy the Polar A370 here:

Polar A370 – Overview

The A370 is not only suitable for people who want to be more active in their everyday life, but also for sports and fitness enthusiasts. The A370 supports a range of sports profiles that help measure more accurate fitness values. It also supports personalized running porgrams based on your fitness level and heart rate, designed to make sure that you train right and avoid overreaching. Programs are available for 5k, 10k, half marathon and marathon events for example. Furthermore, the Polar A370 is waterproof, has a sporty and lightweight design and offers some of the popular Smart Coaching features to accompany your training, including running programs which can be tracked over several weeks and can help you prepare for a semi-marathon.

Polar A370 in Review
Polar A370 in Review

Polar 370 vs 360 – What’s the same?

The Polar A370 and the predecessor model A360 have many similarities. You can find everything you need to know about the A360 in our review. The weight depends on the size variant at a maximum of 37.3g, the display resolution at 80×160 pixels and the water resistance at WR30, which allows the A370 to be worn even during swimming.

The battery life with 24/7 activity tracking and continuous heart rate monitoring is approximately 4 days if you train for 1 hour a day in training mode and deactivate the Smart Notifications.

Furthermore iOS (iOS7 or higher) and Android (Android 4.3 or higher) are supported. In addition, the A370 is compatible with the Polar Balance health scale, the Polar Heart Rate Sensor H10, Apple HealthKit, Google Fit, MyFitnessPal and MapMyFitness.

What’s New?

Compared to the A360, the following features have been added and offer more value:

  • Dynamic 24/7 heart rate measurement in Activity-Tracker mode
  • SleepPlus: Advanced sleep analysis
  • Instant GPS: Integrate GPS of the smartphone into training units
  • Classic watch clasp
  • Use as a heart rate sensor for additional devices via Bluetooth

Some of the new features are presented in more detail below.

Polar A370 Review: Exterior and Processing

While A370 and its predecessor A360 look very similar, only a few details have been improved. In general the A370 is well crafted. This applies to the case including the display and buttons as well as the silicone band. The silicone band makes a very pleasant impression because it is soft and flexible. Newly added is a barely visible ripple on the surface, which ensures that the band does not stick to the annoying clothing lint. It also feels good to wear over several days.

The clasp has also been improved, because it resembles that of a classic watch and leaves a high-quality and stable impression:

Polar A370 Wristband
Polar A370 Wristband

The band can also easily be exchanged for another:

Polar A370 exchangable Band
Polar A370 exchangable Band

The charging mechanism via standard Micro USB charging cable has not changed from the predecessor unfortunately and is still fiddly to use:

Polar A370 USB charging Mechanism
Polar A370 USB charging Mechanism

In this case, the manufacturer would have had to improve and should install a freely accessible water-resistant interface as with Polar’s sports watch M430. The USB port cover does not look so stable.

Display and operation

The Polar A370 has only one button, as well as a touch screen with swiping functions. The touch screen can also lead to issues with the use of sweaty fingers, so the fingers must be thoroughly dry beforehand.

The operation via the button and display is overall reliable and intuitive. The display is similar to the predecessor A360 and with 80 × 160 pixels is readable to a good degree. The readability is somewhat more difficult in direct sunlight, especially when red numbers are displayed, for example when training in the highest HR zone.

Polar A370 Review
Polar A370 Review

The display is usually deactivated and can be activated via typical manual movements, the display or the button. In dark environments (such as dark rooms), the display is very easy to read as soon as it is activated.

24/7 Pulse Measurement with the Polar A370

Previously often desired by Polar fans was 24/7 pulse measurement. This is the pulse measurement for outside the training mode. This has been offered by comparable manufacturers such as Fitbit or Garmin for a long time. On the A360 as well as on all other Polar Fitness trackers, the integrated pulse meter was only active during the training mode.

Polar A370 Heart Rate Sensor
Polar A370 Heart Rate Sensor

With the Polar A370, it now changes, because it measures the heart rate at rest as well as during daily activities automatically. Polar uses a dynamic algorithm, which operates at a minimum of five minute intervals. However, if the sensor detects that the wearer moves with higher activity (for example, when running,) the A370 dynamically adjusts the sampling rate of the heart rate measurement and measures at shorter intervals. The A370 also detects periods of inactivity and records the resting heart rate every five minutes during these rest periods.

Polar A370 Test: Running and Pulse Accuracy

In our tests we took the Polar A370 out for running. Among the highlights are, besides the heart rate sensor, the option to use the smartphone GPS receiver, complete running programs or even the Training Benefit. More advanced features such as statements on the training load, the recovery status or the running index can not be found on the A370. These features are reserved for Polar’s M430 or V800 sports watches.

If you have a smartphone, GPS data can be recorded on it. The speed and the distance covered are recorded. Even without the smartphone, distance and pace can be recorded using the movements of the wrist, such as when walking outdoors or on a treadmill.


For the beginning we went a round jogging. Polar has also catered the A370 specifically for runners, because it can be transferred from flow programs to the A370. Running programs, for example, can be prepared with one of the adaptive Polar Flow training plans on 5 km, 10 km, half marathon or marathon runs. Alternatively, you can also create a training plan that fits your own fitness and individual goals.

Here are some examples from previous Polar tests:

Via the training icon you enter into sports mode and choose your sport. There are dozens of sporting profiles available for polar events. These include walking, biking, group training, walking, swimming, outdoor/indoor sports or yoga, each of which calculates the calories more accurately.

Polar A370 Training Mode
Polar A370 Training Mode

If you start the running training, the Polar A370 automatically searches for a GPS (via smartphone) and heart rate. This process usually takes only a few seconds.

After training and synchronization, the data is available extensively and in detail in the PolarFlow web service as well as in the app, and can also be exported in CSV, TCX or GPX format.

Heart Rate Accuracy

During the A370 test, the Polar M430 as well as the Polars H10 chest strap were included. This allows us to measure whether the A370 Pulse Sensor accurately measures the pulse. If the measured values ​​are superimposed on one another, the following picture is obtained for the first run test:

Polar M430 (red) vs Polar HR10 (blue) vs Polar A370 - Heart Rate
Polar M430 (red) vs Polar HR10 (blue) vs Polar A370 – Heart Rate

It is easy to see that the M430 as well as the A370 need some time until they can keep up with the chest strap. If you know this, however, the training can be prepared accordingly in order to obtain as precise data as possible. This would mean warming up well before the actual workout. Further test data:

  • Polar M430
    • Average: 164 S / min
    • Max .: 182
  • Polar H10 HR chest strap:
    • Average: 165 S / min
    • Max .: 183
  • Polar A370
    • Average: 163 S / min
    • Max .: 182

Polar A370 – New Sleep Features

The Polar A370 combines the continuous heart rate measurement with the new Polar Sleep Plus feature. Polar Sleep Plus automatically detects sleep and wake-up times, the duration and quality of sleep by means of the movements of the wrist. Sleep interruptions should also be reliably detected automatically.

PolarFlow records:

  • Sleep Duration: Shows the entire time frame between sleep and wake-up time.
  • Actual sleep: Indicates how long you’ve slept.
  • Interruptions: Indicate how long you were awake or restless during the night.
  • Sleep Continuity: Shares how constant and regular sleep was on a scale of 1 to 5. A 5 is a sleep without interruptions. The lower the value, the more interruptions were there during sleep.

In the Polar Flow app, the sleep duration can be set to determine a sleeping goal. Sleep can also be assessed retrospectively. Based on the measured sleep data as well as the sleep assessment, flow can give feedback about the sleep quality. In Flow, of course, the long-term sleep rhythm can also be seen.

For example, the flow can look like this:

Polar A370 – Questions and Answers

  • Can the exchangeable wristbands of the A370 be used on the A360?
    • Yes.
  • Does the A370 have a GPS receiver?
    • No, but the A370 / PolarFlow can use the GPS receiver of the smartphone. If you absolutely need integrated GPS, look more like the similarly positioned M430. The M430 is not an activity tracker, but a corresponding larger sports watch with some additional training features.
  • What are the main arguments against the predecessor A360?
    • Intelligent 24/7 heart rate measurement, SleepPlus (extended sleep analysis), GPS via the smartphone.
  • Is the running index supported?
    • Currently not.
  • Will the extended sleep analysis SleepPlus be available for other PolarTracker?
    • SleepPlus can only be used with the A370 and the M430 (as of 25.02.17).

The Competition

These are currently, in our opinion, the strongest Polar A370 competitors in direct comparison:

Comparison: Vivosmart HR+ vs Charge 2 vs A370 vs Band 2 Pro
ProductGarmin Vivosmart HR+Fitbit Charge 2Polar A370Huawei Band 2 Pro
ImageGarmin Vivosmart HR+Fitbit Charge 2 stepsPolar A370Huawei Band 2 Pro
Availability2016 (May)2016 (March)2017 (Jun)2017 (Sept.)
Battery (up to)5 days
GPS: 8 hours
5 days12 days
(24×7 Activity Tracking
+ 1 hours training per day)
21 days
GPS: 3,5 h
(sreps, sleep, calories
WR30 (30 meter)
24/7 HR-measurementYesYesNoYes
via Smartphone
via Smartphone
Warning leaving HR zonevisual
vibration (HR-max)
Smartphone Notif.YesYesYesYes
  • running coach
  • wiping gestures
  • breathing coach
  • be more active
  • battery
  • cardio fitness level
  • be more active
  • resting heart rate
  • comfortable
  • style customizable
  • very good color display
  • wiping gestures
  • be more active
  • training app Polar Flow
  • battery
  • running coach
  • wiping gestures
  • breathing coach
  • be more active
  • battery
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Polar A370 review – Summary

The Polar A370 review is still ongoing, so some details are added on this page. We will finalize the review soon…

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