@everyone “𝗬𝗼𝘂𝗿 𝗪𝗮𝘁𝗰𝗵 𝗠𝗶𝗴𝗵𝘁 𝗕𝗲 𝗟𝘆𝗶𝗻𝗴 𝗧𝗼 𝗬𝗼𝘂"
Wrist-Based Heart Rate Monitors Could Be Costing Your Results

If you are new to triathlon or endurance sports this is pretty important to know now, so come to race day you have the right data to work with.

This is especially important in two main scenarios

1. If you’re using a smart trainer with a power meter indoors and then switching to heart rate as your main metric for measuring cycling intensity outdoors.
2. If you are using Heart Rate to measure run intensity. This is especially useful when “Pace” metrics aren’t as relevant, for example off off-road running. I’ve seen big swings in heart rate which are not related to the intensity an individual is putting in when individuals are using wrist-based heart rate monitors

𝗔𝗰𝗰𝘂𝗿𝗮𝗰𝘆 𝗺𝗮𝘁𝘁𝗲𝗿𝘀 𝗯𝘂𝘁 𝗵𝗲𝗿𝗲’𝘀 𝘁𝗵𝗲 𝗶𝘀𝘀𝘂𝗲:

1. Wrist-based heart rate monitors often fall short during intense or bumpy activity.
2. They rely on light sensors to estimate heart rate, not direct signals from the heart.
3. Studies show their readings can be off by 5–10 beats per minute, especially during running.
4. The errors aren’t consistent. One day it might be slightly low, another day wildly high.

𝗪𝗵𝘆 𝘁𝗵𝗶𝘀 𝗺𝗮𝘁𝘁𝗲𝗿𝘀:

1. If your aerobic threshold is 150 bpm, a 5% error could mean training at 157 bpm.
2. That small shift could reduce recovery, affect adaptations, or hurt race performance.
3. You won’t know if your workout hit the right zone, or just felt hard.

𝗪𝗵𝗮𝘁 𝘁𝗼 𝗱𝗼 𝗶𝗻𝘀𝘁𝗲𝗮𝗱:

1. Use a chest strap or armband for outdoor sessions. It’s closer to 100% accurate.
2. Compare your devices: try 6 x 1-minute hard intervals with your watch and a chest strap. Do they match?
3. If your heart rate data looks random or off, trust the chest strap — not your wrist.

𝗕𝗲𝗳𝗼𝗿𝗲 𝘆𝗼𝘂𝗿 𝗻𝗲𝘅𝘁 𝗯𝗶𝗴 𝘁𝗿𝗮𝗶𝗻𝗶𝗻𝗴 𝗯𝗹𝗼𝗰𝗸 𝗼𝗿 𝗲𝘃𝗲𝗻𝘁 𝗽𝗿𝗲𝗽, 𝘁𝗮𝗹𝗸 𝘄𝗶𝘁𝗵 𝘆𝗼𝘂𝗿 𝗰𝗼𝗮𝗰𝗵.

𝗔𝘀𝗸:

* What heart rate data do you need to guide my training?
* Are my current tools giving us accurate info?
* What can I improve to hit my race goals?

A few beats off might not seem like much, until it is.

@everyone 𝗧𝗵𝗲 𝟮-𝗠𝗶𝗻𝘂𝘁𝗲 𝗪𝗮𝘁𝗰𝗵 𝗖𝗵𝗲𝗰𝗸 𝗘𝘃𝗲𝗿𝘆 𝗧𝗿𝗶𝗮𝘁𝗵𝗹𝗲𝘁𝗲 𝗦𝗵𝗼𝘂𝗹𝗱 𝗗𝗼 ⌚undefined

Simple steps keep it working properly—especially the altimeter.

Your altimeter relies on the 𝘀𝗲𝗻𝘀𝗼𝗿 𝗽𝗼𝗿𝘁 to detect air pressure.
If it’s compromised, your elevation data will be off 📉

I see this happen a lot with triathletes.
It’s often linked to not looking after the watch—especially after pool swims 🏊, open water sessions 🌊, or muddy run adventures 🏃‍♂️

𝗖𝗵𝗲𝗰𝗸 𝘁𝗵𝗲 𝗽𝗼𝗿𝘁.
𝗖𝗹𝗲𝗮𝗻 𝗶𝘁.
𝗞𝗲𝗲𝗽 𝗶𝘁 𝗰𝗹𝗲𝗮𝗿.

𝗪𝗵𝗲𝗿𝗲 𝗶𝘀 𝗶𝘁?
Right side of your watch.
Between the 𝗦𝘁𝗮𝗿𝘁/𝗦𝘁𝗼𝗽 and 𝗕𝗮𝗰𝗸/𝗟𝗮𝗽 buttons.

𝗛𝗼𝘄 𝘁𝗼 𝗰𝗹𝗲𝗮𝗻 𝗶𝘁:
• Run 𝗹𝗼𝘄 𝗽𝗿𝗲𝘀𝘀𝘂𝗿𝗲, 𝘄𝗮𝗿𝗺 𝘄𝗮𝘁𝗲𝗿 over the sensor port 🚿
• Gently remove any visible debris
• Shake off excess water
• Let it air dry completely 🌬️

Don’t use soap or chemicals.
Don’t poke the sensor.

Do this regularly—especially if you swim often.
Once it’s dry, 𝗰𝗮𝗹𝗶𝗯𝗿𝗮𝘁𝗲 𝘁𝗵𝗲 𝗮𝗹𝘁𝗶𝗺𝗲𝘁𝗲𝗿.

𝗪𝗵𝘆 𝗱𝗼𝗲𝘀 𝘁𝗵𝗶𝘀 𝗺𝗮𝘁𝘁𝗲𝗿?
• Your elevation data helps guide effort on hills ⛰️
• It affects pacing
• It improves tracking on multisport days
• It impacts your Training Stress Scores
• It affects your Intensity Factor
• TriDot athletes: You won’t get a good TrainX score and might miss out on a Unicorn 🦄

𝗗𝗶𝗿𝘁𝘆 𝘀𝗲𝗻𝘀𝗼𝗿 = 𝗕𝗮𝗱 𝗱𝗮𝘁𝗮
𝗕𝗮𝗱 𝗱𝗮𝘁𝗮 = 𝗙𝗿𝘂𝘀𝘁𝗿𝗮𝘁𝗶𝗻𝗴 𝘀𝗲𝘀𝘀𝗶𝗼𝗻𝘀
𝗦𝗮𝗱 ☹ 𝗖𝗼𝗮𝗰𝗵 𝗖𝗹𝗲𝗮𝗻𝗶𝗻𝗴 𝗨𝗽 𝗗𝗮𝘁𝗮

Ask yourself:
• When did you last clean your sensor port?
• Are you trusting your altimeter during training?
• Could your race plan suffer because of blocked debris?

It takes 𝟮 𝗺𝗶𝗻𝘂𝘁𝗲𝘀.
Do it after swims, rain, or muddy runs.
𝗣𝗿𝗼𝘁𝗲𝗰𝘁 𝘆𝗼𝘂𝗿 𝗴𝗲𝗮𝗿.
𝗣𝗿𝗼𝘁𝗲𝗰𝘁 𝘆𝗼𝘂𝗿 𝗽𝗿𝗼𝗴𝗿𝗲𝘀𝘀.

For more information visit https://support.garmin.com/en-NZ/?faq=pCL0xvX9lj8hdtZcNf1ZAA