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Garmin HRM Pro vs Tri (2021): Which Heart Rate Monitor Is Better?

Garmin’s premium chest straps offer a more convenient and accurate way of monitoring your heart rate. After all, it’s not always easy to work out and train while carrying a phone or wearing a bulky smartwatch. Among Garmin’s lineup of heart rate monitors, however, the Garmin HRM-Pro stands out the most. The pro-level heart strap is packed with features and comes with upgraded connectivity options.

Meanwhile, athletes on a budget can opt for the slightly more affordable models, including the Garmin HRM-Tri. It offers almost similar monitoring capabilities as the HRM-Pro but cuts corners in a few areas. In this review, we check out where the Garmin-PRO excels and where the HRM-Tri skimps.

Garmin HRM Pro vs Tri Comparison Chart

ModelGarmin HRM-ProGarmin HRM-Tri
 Amazon productAmazon product
PriceAmazon productAmazon product
Real-time Heart Rate TransmissionYes, via ANT connectivity and BluetoothYes, via ANT connectivity
Heart Rate VariabilityYesYes
Running DynamicsYesYes
Stores HR Data For SwimmingYesYes
Stores HR Data For Standalone Use Cases YesYes
Daily Metric TrackingYesNo
Garmin Connect App CompatibleYesNo
Water Rating5 ATM5 ATM
Battery Life12 months10 months
Connectivity2.4 GHz ANT+, Bluetooth 5.02.4 GHz ANT+
Dimensions (L x W x D)60-142 x 3 x 1.2 cm60-142 x 3 x 1.2 cm
Size AdjustmentBi-foldBi-fold


The Garmin HRM-Pro and HRM-Tri look the same except for the colors of their module’s bezels.

The Garmin HRM-Pro (left) has a yellow-green bezel while the HRM-Tri (right) comes in blue.

Except for the color of the HRM module’s bezel, it’s hard to tell the difference between the Garmin HRM-Pro and HRM-Tri. Both devices use the same soft fabric for the strap. They even share the same weight and dimensions. Now, the skin-facing side of these monitors contains two electrodes, one on the left and the right. Users must then wet these sensors for a stronger connection between the chest and transmitter before wearing the straps.

Garmin indicates that the minimum chest size for both is 60 cm. or 23.5 inches, while the maximum is 106 cm. or 23.5 inches. Users who don’t fall in this range can get the HRM strap extender instead. In addition, the module on the HRM-Pro and HRM-Tri is not removable like that of the HRM-Dual. Where the two have an advantage, however, is that they are both water-resistant up to 5ATM.

The HRM-Pro and HRM-Tri, however, are better suited for open water swimming. This is because the straps of these monitors are thin and can be pushed down as you flip or turn in the pool. For pool swimmers, Garmin recommends the HRM-Swim device instead.

Running Dynamics

Garmin’s ergonomic heart rate monitors capture running dynamics to improve one’s running form.

While both track running dynamics, the Garmin HRM-Pro (left) monitor advanced metrics.

The module on the Garmin HRM-Pro and HRM-Tri contain an accelerometer that monitors torso movement. This component is what calculates the different metrics for Running Dynamics. Both straps do have this feature, although the HRM-Pro captures more data than the HRM-Tri.

On the HRM-Tri, users can monitor cadence, vertical oscillation, and ground contact time. Cadence is essentially a measurement of how many steps you take per minute on both feet. Vertical oscillation, on the other hand, refers to how far you travel up and down with each step. Meanwhile, ground contact time measures the amount of time a step is in ‘contact’ with the ground.

The HRM-Pro, however, adds ground contact time balance, stride length, and vertical ratio to the three existing metrics of the HRM-Tri. Ground contact time balance helps users see how balanced or symmetrical their running form is. Next, stride length refers to how far you travel with every step on both the left and the right. Vertical ratio, on the other hand, calculates running efficiency by dividing vertical oscillation by stride length.

Other Use Cases

While the Garmin HRM-Tri can be used for running, swimming, and cycling, the HRM-Pro adds to its functionality by monitoring daily metrics.

Both the Garmin HRM-Tri and HRM-Pro can be used for cycling, swimming, and running.

The Garmin HRM-Tri is designed with triathletes in mind. The strap is compatible with activities like running, open water swimming, and bike rides. For bike rides, the strap can record activities when connected to a supported watch. According to Garmin, the HRM-Tri is compatible with other wearables used for cycling, including the Garmin Forerunner and Garmin Fenix.

The Garmin HRM-Pro builds on these key features of the HRM-Tri. However, it also has the ability to monitor daily metrics typically captured by your smartwatch. Aside from heart rate, the HRM-Pro can measure steps, all-day heart rate, calories, and even intensity minutes. This is useful if you have to leave a device to charge but need to train or workout. All the metrics recorded by the HRM-Pro will still be updated across Garmin Connect-compatible devices.

Battery and Connectivity

The Garmin HRM-Pro has a longer battery life and Bluetooth 5.0 than the Garmin HRM-Tri.

Unlike the Garmin HRM-Tri, the Garmin HRM-Pro has both ANT+ and Bluetooth connectivity.

Garmin’s heart rate monitors are not rechargeable devices. Instead, they use a replaceable CR2032 battery. The company shares the Garmin HRM-Pro’s battery should last twelve months, for an hour a day of training. Meanwhile, the Garmin HRM-Tri’s battery life is about ten months.

Both the HRM-Pro and the HRM-Tri devices use ANT+, a wireless technology that allows the one-to-many connection. The HRM-Pro, however, can also transmit data to Bluetooth simultaneously, a feature absent on the HRM-Tri. It’s a feature originally introduced in the Garmin HRM-Dual. For athletes, this is convenient if you want to transfer data in real-time to multiple compatible devices and apps. It’s especially useful when using online platforms like Zwift.

Since connectivity can be lost while you’re swimming, the HRM-Pro and HRM-Tri will store data locally. Once the connection โ€” either via ANT+ or Bluetooth โ€” is re-established, data will be transmitted back to the supported watch. This means no information is lost throughout your activity.


If you’re willing to spend extra bucks, you’ll find the Garmin HRM-Pro is a better version of the Garmin HRM-Tri.

Amazon product

Choosing between the Garmin HRM-Pro and HRM-Tri is never going to be about design. The two heart rate monitors look the same after all, with the exception of their module’s colors. Where the HRM-Pro does have an advantage is its support for daily activity monitoring and the inclusion of Bluetooth connectivity. Daily activity monitoring means you can check out standard fitness metrics even without your smartwatch. Bluetooth connectivity, on the other hand, allows you to connect the strap to multiple devices and apps.

The Garmin HRM Pro also has a slight advantage over the HRM-Tri when it comes to running dynamics. But while the new metrics are a welcome feature for runners, it’s not going to be the main game-changer. If you’re happy with the feedback you get from the Garmin HRM-Tri, the advanced data you get from the Pro isn’t going to be revolutionary. For what it’s worth, however, the HRM-Pro feels a lot more future-proof than any of the brand’s current heart rate monitoring straps.


๐Ÿ“Œ What’s the difference between the Garmin HRM-Pro and the HRM-Tri?

The Garmin HRM-Pro supports ANT+ like the HRM-Tri but also adds Bluetooth to its connectivity features. The Garmin HRM-Pro also offers advanced metrics for running dynamics and the ability to monitor daily metrics.

๐Ÿ“Œ Is the Garmin HRM-Tri rechargeable?

No, the Garmin HRM-Tri is not rechargeable. The heart rate strap uses a lithium coin battery instead.

๐Ÿ“Œ How many connections can be supported by the Garmin HRM-Pro’s ANT+?

The Garmin HRM-Pro supported unlimited concurrent ANT connections.

๐Ÿ“Œ Are chest straps better than wristwatch trackers when monitoring heart rate?

Yes, chest straps like the Garmin HRM lineup offer more accurate heart rate readings compared to wrist-based monitors.

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Mari Bassig

Senior Editor, writer and researcher passionate about gadgets, social media, and music.