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Everything You Need to Know About Your Heart Rate Sensor

Oh, technology! I love it when it’s working, but when it’s not working it’s enough to drive me bananas. (Can I get an amen?) And for me, a heart rate sensor is no exception!

However, over the years I have learned quality care and little tricks with a heart rate monitor can go a long way! Using a heart rate sensor with PK Fitness will give you a real-time effort score as you workout. And to me, the value I get from knowing my effort is an invaluable part of my workout.

Follow along with my top tips below so that you can enjoy your heart rate sensor to the fullest!!

Choosing a Heart Rate Sensor

Electrical Technology vs. Optical Technology

There are a few different types of technology out there that can read your heart rate. Electrical technology tends to be most accurate, and is commonly found in chest strap heart rate sensors. It reads the electrical signal from the pulse of your heart.

Optical technology on the other hand, is what is found in the Apple Watch, Fitbit, and similar sensors. This technology uses a light to read blood flow data which helps the device generate a reading of your pulse. One downside of these sensors is because they work with light, they can have trouble getting a reading for individuals with lower body fat, or darker skin.

Bluetooth/ ANT+ Technology

When looking for a sensor to pair with PK Fitness you will need a HR sensor that has Bluetooth/ANT+ technology. Without this technology your HR sensor won’t be able to connect to your phone. What makes this connection special is that PK Fitness is able to receive information about your heart rate, and provide you with instant feedback on your effort during your workout!

Activity Type

Depending on your favorite activities, you may find that different sensors suit your needs! For example, a chest strap is great for general activities like running, walking, circuit/HIIT style workouts. I use the PK Fitness chest strap for all my workouts, and in general it works pretty seamlessly for me. I also know some fans of the Wahoo chest strap, which is more expensive but comes with some neat features like memory, treadmill mode, cycling cadence, etc.

However, a chest strap might get in the way for more intense activity like cross fit, jiu jitsu, or other sports. For activities like these, I would suggest the Scosche Rhythm Arm Band which you can wear either on your upper arm, or near your ankle. What makes it so great is that it’s made out of neoprene, a very pliable material. AND it’s not bulky or touchy like an Apple Watch or other wristwatch model that you might avoid wearing during sports. Because of its pliability it also can fit very snugly unlike a lot of molded wrist wear accessories.

For water sports, many sensors are now water resistant. However, any sensor that is dependent on a bluetooth connection with a phone/device will have trouble making that connection through water. That’s why with swimming your best bet will be an option like the Apple Watch 2 or 3 which act both as the sensor and as the device hosting PK Fitness. Finally, Apple Watch 2 and 3 are winners because they are waterproof, and a great option for those who highly value quick visual feedback throughout their workout.

Getting the Best Sensor Connection

Bluetooth Turned On and Connected to Device

To ensure your HR sensor can connect to your phone/device, you will need to make sure that bluetooth is turned on in your phone settings. The simple steps for this are as follows:

#1) Go to Settings in phone.

#2) Click on Bluetooth.

#3) Turn Bluetooth On.

#4) Wait for heart rate monitor to appear in Bluetooth.

Sensor not connected to any other apps or sources

Sometimes your heart rate sensor might be connected to bluetooth, but also connected to a different app. This would make the sensor unavailable to connect to PK Fitness.  If you know what app it’s connected to, simply disconnect the monitor from within the other app. If this doesn’t work try closing out of the other app altogether. Then reopen PK, and try to connect the sensor again.

Directly on Skin

You will need to have your heart rate sensor directly on your skin to get a reading. For wrist sensors, attach the sensor a little further up the arm, out of the way of any bony protrusions. These little bones at your wrist might distort the position of the sensor.

For chest straps, make sure to tuck the sensor under any articles of clothing. Side note, ladies, rather than letting your chest strap compete with the edge of your sports bra, tuck it under the bottom edge to hold it in place.


Whatever sensor you’re wearing it needs to be snug. If a chest strap or similar band isn’t snug it will slide around during your workout and have a harder time getting a heart rate reading. If you’re wearing a sensor using optical technology, outside light might get in and mess with the light technology that’s trying to read your blood flow.

Turned On

Some sensors- like a chest strap- read your heart rate as soon as they’re touching your skin and can pick up a pulse. Whereas some wrist sensors may require you to push a button so that the device knows it’s looking for your heart rate.

Give it Time

It may take a little time for your heart rate monitor to find your pulse. This is actually pretty standard. I put my sensor on while I’m getting ready in the morning, or on with my outfit before I head to the gym so that it has some time to pick up on my heart rate, and is warmed up and ready to go once I’m ready to workout!


This might sound a little weird, but a little moisture for a heart rate monitor is actually a good thing! Usually sweat will do the trick, but if you’re particularly dry, wet the back of your sensor with a drop or two of water before putting it back on to try again.

Fresh Battery

Batteries don’t last forever. With some sensors, you can recharge at night. With other sensors like the chest strap, you’ll have to replace the battery every so often. Sometimes when battery power gets low the connection starts getting a little iffy, this is a good reason to always have a fresh battery in your sensor!

A little tip for care with your chest strap if you have one- that battery that’s in the little sensor piece isn’t turned on unless it’s connected to the actual strap. Remove the sensor from the strap when you’re done working out to save the battery.


Good luck, and let me know any of your tips and tricks you’ve found to be helpful with your HR sensor!

Stay fit,
Sydney Eaton

PK Fitness Program Coordinator, CPT, CES

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