What’s worse: eating a salad laced with broken glass, or your heart rate monitor not working? If you answered B, you have likely felt that special rage that happens when your expensive device spikes to 267 bpm — or stops reading altogether.
I’ve spent the last couple of months troubleshooting my overpriced, extremely high-maintenance Suunto Smart Sensor with mixed success. (Yes, once in awhile it still reads when hanging in mid-air. Maybe it’s taking the heart rate of ghost or something?)
However, this whole experience has forced me to read roughly 867 articles about heart rate monitors and their care and maintenance. I’ve also tried everything from wearing it on my back to washing it with organic botanical shampoo. I haven’t yet tried an exorcism (though I’m starting to wonder).
So if you’re struggling with a heart rate monitor not working, here are my recommendations.
Replace the battery chest strap battery.
When you call and get service, the manufacturer will likely insist on this. Even if you have a new device, they will tell you, it may have been sitting on the retailer’s shelf for a long time. Most chest strap heart rate monitors use button cells (watch batteries).
My coach says that when her heart rate Suunto heart rate monitor is reading inaccurately, it’s often a sign that it needs an update. This is usually accomplished by connecting your chest strap to an app via bluetooth. Check your devices documentation for specific instructions.
Make sure you’re wearing it right-side up.
Some heart rate monitors (Suunto SmartSensor comes to mind) will read less accurately when worn upside down. Make sure both the strap and the sensor itself (which snaps into the strap) are oriented correctly.
Put it on a few hours before your run.
The electrodes in the heart rate monitor chest strap must be moist in order to read accurately. One of the easiest ways to do this is to put your heart rate monitor on a few hours before your run. This allows time for sweat to form between the electrodes and your skin.
Lick the electrodes.
If a little sweat isn’t enough to conduct the signal accurately, give each electrode a big, sloppy lick. Depending on how hydrated you are, this usually does the trick.
Use conducting gel.
Sometimes during longer workouts, I find that my heart rate monitor electrodes dry out after an hour, and the signal degrades. This is especially common in the dry winter months. One of the best ways to prevent this is to use a conducting gel. Here’s my favorite inexpensive conducting gel, available on Amazon.
But not too much conducting gel.
In my experience, too much of a good thing is a bad thing. When the gel starts oozing off the electrodes and onto the belt, it can cause the heart rate monitor to read inaccurately. It can also cause the chest strap to slip around and lose signal. If you’re having problems during a workout, try giving the excess gel a swipe with your finger.
Make sure you know where the electrodes are.
For the longest time, I was licking and gelling the wrong spots on my heart rate monitor. Most monitors have two electrodes located in the strap. The back of the sensor is not an electrode.
Tighten the strap.
It’s funny. My friend can just throw her strap in her bra (without fastening it) and get a good reading. But in my experience, a lot of people can’t get an accurate reading unless the electrodes are tight against the skin.
Try different clothes.
Certain fabrics cause static that can interfere with your heart rate monitor’s reading. I have one particular sports bra that my Suunto heart rate monitor genuinely appears to hate. It’s a bright color that sometimes bleeds into light colored shirts. Maybe there’s something in the dye that interferes with conductivity?
Rinse it off.
Check the cleaning instructions from your manufacturer. Most chest strap heart rate monitors (including the sensor) should be lightly rinsed after every run.
Wash the strap.
Now that you know the electrodes are located in the strap, you can imagine how deposits of sweat and body fluids interfere with conductivity. Give your chest strap a good wash after every few workouts … or any time the heart rate monitor signal is getting flaky. I like to soak mine overnight with a little bit of laundry soap. Some chest straps can be laundered in the wash machine. Again, check your manufacturer’s documentation for instructions.
Deep clean it.
If you’re really having trouble, give your heart rate monitor a spa day before you throw up your hands. Here’s an excellent tutorial on deep cleaning your device from Nat Harward.
Test before you go out.
If your heart rate monitor tends to flake, give it a trial run at home before you head out to work out. It’s a lot easier to wash, gel, lick, and troubleshoot at home than when you’re freezing at the trailhead. Also, if you’re a girl, this will save you the weirdness of repeatedly lifting your shirt in public.
Give it a flick.
If your heart rate monitor starts going berserk during a workout, flick it hard enough with your finger to unstick it from your chest. Sometimes losing and reestablishing conductivity helps it reset the signal.
Give it 15 minutes.
Sometimes a heart rate monitor that starts our reading flaky will normalize after you start to sweat.
Return it or make a warranty claim.
I can tell you from experience that some heart rate monitor models are better than others. If you’ve got one of the crappy ones, don’t be shy about seeking a warranty repair. Or you may be able to unload it for a refund you bought from a retailer with a good return policy like REI.
Above all, don’t let it ruin your workout.
Screaming at your heart rate monitor, obsessing over it, and stopping every five minutes to futz with it won’t make it work better. And it won’t help you get a better workout.
While heart rate training is awesome, research shows that ratings of perceived exertion (RPE) will also help most people exercise at the right intensity. To learn more, check out my blog post on Stupid Simple Heart Rate Training.
What should you replace your high-maintenance diva of a heart rate monitor with? My money’s on the surprisingly affordable Wahoo Tickr. If far outperforms the Suunto Smart Sensor for half the price. The Wahoo Tickr actually pairs faster with my Suunto watch than the native Smart Sensor! For more info, check out my complete Wahoo Tickr review.
So there you have ’em. All the ways to deal with a heart rate monitor not working.
Got any to add? Comment below to share.
Originally published February 19, 2020.