Polar RS300 X

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Polar RS300 XReview Facts

The Polar RS300X heart rate monitor watch is a multi-sport training computer and heart rate sensor. It allows athletes to monitor, control and track their heart rates, length and speed of the workout, and a calorie meter. The Polar RS300X Heart Rate Monitor Watch also tracks the calories burned and training intensity guide. It’s an accurate watch built for those that want a user-friendly experience. Designed and released in 2009 by Polar, it’s compatible with two available sensor expansions. Those being the S1 Footpod Sensor and the G1 GPS Sensor. With a display screen that features easy to use menu functions, it’s the perfect watch for new and continuing Polar users.

  • Big and easy to see display
  • View real-time training information
  • Polar OwnZone feature that helps avoid over-training and under-training
  • Data saved from up to 16 training sessions.
  • Ability to transfer data to a PC or Mac via Polar FlowLink.
  • View information from the add-ons (G1 GPS Sensor and S1 Footpod) on the training computer.
  • Occasionally the transmitter fails to connect or seems faulty.
  • Accessing all the features can be difficult if you are not tech savvy.
  • Add-ons can make the heart rate monitor slow.

Size / Weight

The heart rate chest sensor is quite small and thin, making it hardly noticeable when wearing snug tops. The wristband measures 8.5 inches from the last hole to the end of the rubber. The watch comes with an H1 heart rate sensor chest strap for accurate and continuous heart rate measurements. The Polar RS300X has a water resistance display of up to 165 feet (50 meters) of depth.

Heart Rate Monitoring

The heart rate can be easily seen by just pressing a single button without needing to record it first. To record the heart rate, you can simply press the same button twice.

Data Transfer / Recording

Though you can’t pair it completely with your mobile devices, you do have the ability to transfer the data files. It is compatible with PC, Mac (Intel-based) and polarpersonaltrainer.com via Polar FlowLink.

Multi-Sport Modes

Whether you’re running, spinning, swimming, or doing cardio – the Polar RS300X Heart Rate Monitor Watch can suit all sports. The 50 meters of depth water resistant come in handy when doing laps around the pool. You can easily check your heart rate without having to stop in the middle of an intense workout. The Polar Sports Zones allow you to easily select and monitor the training intensity based on the sports program. It is divided into five zones: very light (50-60% max HR), light (60-70% max HR), moderate (70-80% max HR), hard (80-90% max HR), and maximum (90-100% max HR).

You can also do interval trainer guided workouts that are based on your heart rate, distance and pace as well as attain guidance through the training sessions.


The one-piece watch strap is molded into the watch. It doesn’t hinder the buttons or the watch display. It is lighter and has more stretch than other Polar watch models. It’s suggested that you use around eight inches of space to allow enough tension to keep the strap as taut as possible. The strap doesn’t chafe and is made of a semi-soft material, making it easy and comfortable to wear. The chest band measures at around 38 inches and can stretch up to 50 inches.


The watch informs you of any large changes through an audible and visual alarm. The alarm will warn you if your heart rate, pace, or speed exceeds or falls from the pre-set limits of your target zone.

The display text can be set to English, Spanish, French, and German. It also works on a dual time zone and a 12 hour or 24-hour time set with an alarm (+ snooze) button.

Compatible Activity Apps

You can use Polar FlowLinkÒ to upload the training session data onto a PC or Mac.

Another compatible app is the Polar OwnZoneÒ that helps the user avoid under-training and over-training. This is done with the real-time feedback provided to the users about their current state (or lack) of readiness. The data can depend on the time and day, stress levels, tiredness or not fully recovered from previous sessions.

Polar OwnIndex Fitness Test can calculate your aerobic fitness and provide a reference to the training intensity and how to measure any improvement.

Polar OwnCal shows the energy spent for each exercise session. This program accurately calculates the number of calories you burn per session. The calculation will be based on your height, weight, gender, age, and workout intensities.


The main screen can be personalized depending on which three parameters you wish to see. Most people have set up the screen to view their calories, heart rate and elapsed time. There are two colors – black and orange – available for purchase.

Metrics & Analytics

The Polar RS300X Heart Rate Monitor Watch has the ability to track your latest sixteen training sessions as well as the last sixteen weeks of training. It can measure up to 99 laps. The watch provides metrics for speed, heart rate, distance, calorie burn, and pace. You can adjust the max heart rate indicator to your preferences. An automatic ideal heart rate is set up according to your age. You can also manually set up your target zone to what is suitable for your training. It can be set as beats per minute (bpm), as a heart rate reserve percentage (HRR%), or as a maximum heart rate percentage.

The watch allows for automatic lap recordings based on a pre-set distance as well as graph your current intensity zone during your training session.

Real Time Data Tracking

The training computer display shows three different measurements simultaneously. The three that are shown are completely up to the user. They can choose to set a screen to display peak heart rate, average heart rate and the lap time. It also gives you your average and maximum heart rate for each lap and the entire workout.

The Polar OwnCode is a coded heart rate transmission that transmits your heart rate to the training computer. The training computer will only pick up the heart rate that is emitted from your transmitter.

The Polar Fitness Test can measure your resting aerobic fitness in about five minutes. The result comes through Polar OwnIndexÒ which evaluates your maximal oxygen uptake (VO2max). The test is based upon your heart rate and its variability as well as any additional personal information that is provided.

Key Features of the RS300 X

• Coded transmission (Polar OwnCodeÒ) between the heart rate sensor and the training computer to avoid any potential interruptions.
• Customizable display – user can pick three training parameters to see in real time.
• Polar Fitness Test allows users to create a benchmark to test their progress throughout their workouts.
• Target heart rate zones, including audible and visual alarms for safety.
• Display calories burned (Polar OwnCalÒ).
• Manual target zone setting
• Adjustable maximum heart rate indicator set by the user.
• Automatic heart rate indicator set based on your age.
• Heart rate variability (Polar OwnZoneÒ) that can determine the recommended intensity of training.


For the features that the Polar RS300X Heart Rate Monitor Watch has, compared to its price, it’s an excellent choice to buy. The heart rate variability along with the customizable display outweighs any negatives that the product might have. In the case of this watch, there are enough pros compensating the cons.

This device also comes with an option to purchase the GPS and FootPod add-ons, making the watch have an ever expanding list of features. The Polar RS300X Heart Rate Monitor Watch is also compatible with the Polar RC3 GPS, which has several built-in features, including distance, speed, and route tracking.

If you’re looking for an affordable but quality heart rate monitor – Polar RS300X Heart Rate Monitor Watch is the perfect choice for you. The basic model is enough for most people, especially if they do not want a GPS included. Overall, this product has everything that a user could need to track their progress, no matter what sport they choose to partake in.