Garmin HRM-TRI Owner's Manual

See the Important Safety and Product Information guide in the 

product box for product warnings and other important 

information.

You should wear the heart rate monitor directly on your skin, just 

below your sternum. It should be snug enough to stay in place 

during your activity.

If necessary, attach the strap extender to the heart rate 

monitor.

Wet the electrodes 

À

 on the back of the heart rate monitor to 

create a strong connection between your chest and the 

transmitter.

Wear the heart rate monitor with the Garmin

®

 logo facing 

right-side up.

The loop 

Á

 and hook 

Â

 connection should be on your right 

side.

Wrap the heart rate monitor around your chest, and connect 

the strap hook to the loop.
NOTE: Make sure the care tag does not fold over.

After you put on the heart rate monitor, it is active, storing, and 

sending data.

Before you can pair the heart rate monitor with your device, you 

must put on the heart rate monitor.
Pairing is the connecting of ANT+

®

 wireless sensors, like your 

heart rate monitor, with a Garmin ANT+ compatible device.
NOTE: The pairing instructions differ for each Garmin 

compatible device. See your owner's manual.
• For most Garmin compatible devices, bring the device within 

3 m of the heart rate monitor and use the device menu to pair 

manually.

• For some Garmin compatible devices, bring the device within 

1 cm of the heart rate monitor to pair automatically.
TIP: Stay 10 m away from other ANT+ sensors while pairing.

After you pair the first time, your Garmin compatible device 

automatically recognizes the heart rate monitor each time it is 

activated.

You can use your compatible Garmin device paired with the 

HRM-Tri

™

 accessory to provide real-time feedback about your 

running form. If your Garmin device was packaged with the 

HRM-Tri accessory, the devices are already paired.

The HRM-Tri accessory has an accelerometer in the module 

that measures torso movement in order to calculate three 

running metrics: cadence, vertical oscillation, and ground 

contact time.
NOTE: The HRM-Tri accessory is compatible with several ANT+ 

fitness products and can display heart rate data when paired. 

The running dynamics features are available only on some 

Garmin devices.
Cadence: Cadence is the number of steps per minute. It 

displays total steps (right and left combined).

Vertical oscillation: Vertical oscillation is your bounce while 

running. It displays the vertical motion of your torso, 

measured in centimeters for each step.

Ground contact time: Ground contact time is the amount of 

time in each step that you spend on the ground while 

running. It is measured in milliseconds.
NOTE: Ground contact time is not available while walking.

Hand wash the heart rate monitor after exposure to chlorine or 

other pool chemicals. Prolonged exposure to these substances 

can damage the heart rate monitor.

The HRM-Tri accessory is designed primarily for open water 

swimming, but it can be used occasionally for pool swimming. 

The heart rate monitor should be worn under a swim suit or 

triathlon top during pool swimming. Otherwise, it may slide down 

your chest when pushing off the pool wall.

The heart rate monitor records and stores your heart rate data 

while swimming. Heart rate data is not visible on compatible 

Garmin devices while the heart rate monitor is underwater.
You must start a timed activity on your paired Garmin device to 

view stored heart rate data later. During rest intervals when out 

of the water, the heart rate monitor sends your average and 

maximum heart rate for the previous interval, and your real-time 

heart rate, to your Garmin device.
Your Garmin device automatically uploads stored heart rate data 

when you save your timed swim activity. Your heart rate monitor 

must be out of the water, active, and within range of the device 

(3 m) while data is uploaded. Your heart rate data can be 

reviewed in the device history and on your Garmin Connect

™ 

account.

The heart rate monitor can store up to 20 hours of data in a 

single activity. When the heart rate monitor memory is full, your 

oldest data is overwritten.
You can start a timed activity on your paired Garmin device, and 

the heart rate monitor records your heart rate data even if you 

move away from your device. For example, you can record heart 

rate data during fitness activities or team sports where watches 

cannot be worn. Your heart rate monitor automatically sends 

your stored heart rate data to your Garmin device when you 

save your activity. Your heart rate monitor must be active and 

within range (3 m) of the device while data is uploaded.

If the heart rate data is erratic or does not appear, you can try 

these tips.
• Reapply water to the electrodes and contact patches (if 

applicable).

• Tighten the strap on your chest.

2

Installation Instructions