Polar RS300X Heart Rate Monitor

The RS300X is a heart rate monitor and sports watch aimed at recreational athletes who are looking for all the important heart rate and timing features. The RS300X is different from the FT range of heart rate monitors in that it has built-in features for handling laps, which makes it a great watch if you’re doing any sort of circuit training, running, and/or swimming, since it’s water resistant down to 50m.

Polar RS300X Heart Rate Monitor Best Price

The following are the current prices for the Polar RS300X, we update these prices daily to ensure you always get the best possible price.

Polar RS300X Heart Rate Monitor Features

The RS300X has automatic heart rate target-zone features, with both visual and audible alarms to alert you if you fall outside the desired range. It’ll record the average and maximum heart rate of your entire training session, and the average and max heart rate of each lap. There’s the Polar sport zones feature, which provides you with an easy way to track the intensity of your training session by dividing your training into five zones depending on your current max heart rate (MHR) setting. There’s very light (50%-60% MHR), light (60%-70% MHR), moderate (70%-80% MHR), hard (80%-90% MHR), and maximum (90%-100% MHR).

You have access to Polar’s online training system, polarpersonaltrainer.com, where you can keep an online training diary, transferring the data from your watch to the site after each workout for a long-term record of your training and progression. You’ll be able to see your “Polar Sport Zones” training zones here so you can actually see how hard you were training at various points in the workout.

Like all the Polar products, the RS300X comes with the Polar HeartTouch feature, which allows you to change the display on your watch by moving your watch hand closer to your heart strap on your chest. Additional features include the ZonePointer, which is a graphical symbol on your watch showing you where you are in your target heart rate zone, so you can determine if you need to change speed/pace etc.

The Polar Fitness test is available on the RS300X, and it allows you to quickly and easily measure your fitness level by recording your resting heart rate, and then displaying your VO2Max. Polar OwnCal will display your calories burned and calculate the amount of those calories that came from fat in your body.

You can optionally purchase either the GPS unit or the S1 footpod to track your distance/pace/speed while running. If you’re serious about your running then this is a must-have feature, as it allows you to keep a very detailed log of your running activities in your online training diary so you can see how your fitness is progressing, and make any alterations necessary to your training program.

Using the Polar RS300X

During training the RS300X feels comfortable and the display is easy to read at a glance, even while running. The design is visually very appealing, and the heart rate strap feels comfortable on your chest. The watch is easy to use while training because of the HeartTouch feature allowing button-free operation. The best part about the RS300X is the ability to upload the detailed training results to Polar’s online training diary at polarpersonaltrainer.com. The amount of training related guidance, programs, and information on the site really sets this watch apart from the cheaper models that only display a training summary on the watch. The online training diary is a lot of fun and can really motivate you to train that bit harder when you see just how much you’re progressing in such a short period.

Comparing the Polar RS300X to Similar Heart Rate Monitors

Upgrade Model: none.There’s no direct upgrade in this line of sports watches. This is the highest spec sports watch from Polar that has support for laps.

Downgrade Model: the RS100 The Polar RS100 heart rate monitor has significantly less features, no online training diary or access at all to polarpersonaltrainer.com, and no support for a GPS unit or the S1 footpod.


The RS300X is a great sports watch that adds so much to your workouts, with all the essential features, plus the ability to handle laps and upload your training records to the online training diary; it’s an essential piece of kit for any recreational athlete.