In this article we will:
- Define HRM
- HRM vs fitness tracker
- Why Monitor your HR
- Types of HRM and Accuracy
- What I use and recommend for Dad
Heart Rate Monitor (HRM) Defined
A HRM is a piece of wearable technology that reads your heart rate, also known as your pulse. Today there are activity trackers and heart rate monitors together in one piece of wearable technology.
These duo devices have their place but if you are looking for reliable HR data I don’t recommend the duo devices.
Polar is the grandfather of HRM technology. I actually remember my first HRM, it was an A1, I believe. It included a chest strap and a wrist watch. The chest strap read your pulse and sent the information to the wrist watch. It worked great as long as you were not running with a friend who also had a HRM. The display was big and the numbers were bold. As a teenager, I didn’t appreciate that I like do now.
HRM vs. Fitness Tracker
Let’s quickly discuss the difference between a HRM and Fitness Tracker. A HRM reads your heart rate; a fitness tracker tracks your steps, your active minutes, and maybe flights of stairs. Okay, here is where it gets a little tricky. A fitness tracker may have the ability to monitor your HR and a HRM may have a the ability to track your activity. Like I stated earlier I don’t recommend one unit to do both. Let a fitness tracker track your activity and let a HRM track your HR. The reason being, most fitness trackers will use optical technology to determine your HR. There are many limitations to this technology, which we will get into.
Why Monitor Your HR?
People monitor their HR for various reasons:
- Endurance training/Zone Training
- Doctor’s orders
Whatever your reason, I feel if you are looking at your HR you are looking for accurate information. What is the point of monitoring your HR if you can not be confident in the information?
Accuracy comes down to which technology you are using to monitor you HR.
There are basically two types of technology we can use to read your HR. The old school, chest strap or the fairly newer technology, the optical light.
The Old School HRM – Chest Strap
The chest strap is by far the most accurate – most have the accuracy of ECG readings. Specifically, the The Polar H7 Bluetooth chest strap has been shown (in a paper published in JAMA Cardiology) to have the accuracy of an ECG. (Note: the H7 has since been replaced by the H10)
There are some drawbacks to the HR chest strap. Some people find the chest strap uncomfortable. Personally I forget it’s even there, and I have had clients leave a session wearing my HR strap because we both forgot they had it on. On the other hand, there are some who complain that it causes chaffing. That one I can totally relate to. Back when I was quite the endurance queen I had a permanent mark in the middle of my chest. Nothing serious, I just needed a little Aquaphor ointment.
In the old days the chest strap would send a signal to a watch worn on the wrist and this would be how you read your HR.
Today many people opt to have a HR chest strap that is bluetooth enabled and read the HR via an app on their phone.
A few quick tips to know about your chest strap:
- Always disconnect it. Leaving it connected will run down the battery.
- Always get the electrodes wet before using it.
- Some models are available in various colors which makes finding your HR strap in your gym bag much easier!
The Newer HRM Option – LED Optic Lights on Your Wrist Unit
Many of your activity trackers, including your Apple watch, use green LED lights to detect the amount of blood flow through your wrist. When your heart beats, the blood flow in your wrist is greater and the green light is then absorbed more. The HR is determined by measuring the changes in the amount of green light that is absorbed. There are a bunch of fancy algorithms that help it do this.
The accuracy of products that use light to sense your blood flow to then determine your HR is very limited. You may have heard that the FitBit (a popular activity tracker that has some models that read HR) has had lawsuits filed against them because the HR readings have been found to be so inaccurate. According to Consumers Reports it’s not that their technology is worse than other green LED products, but their advertising was inaccurate and made too big of claims.
According to, David Wright CEO of myZone, “…the thing with a lot of these optical blood flow wearables. If you’re just walking and running then they have good algorithms to get rid of light and movement artifacts, but if the intensity is a lot higher, above 160 beats, then the blood passing is so fast that when you add movement as well, it becomes really difficult to get the right reading”
It does not matter if your wrist worn activity tracker is made by Apple, FitBit, Polar or Garmin, the optic technology that these units use has been found to be somewhat accurate for walking or jogging at a steady state, but not accurate for weight training or interval training.
What do I use and recommend for my Dad?
I love my Apple Watch. It is a fitness tracker; it tracks my steps, how much I sit, how active I am, and I can look at my HR during a dog walk or even during a workout. I just know that when I look at my HR during a workout it will be wrong. Although they say the the green led light technology is supposed to be pretty good during walking and steady state exercise I don’t find it to be too reliable even while walking Kami, our 9 year old Vizsla.
When I go to a cycle class in a few hours, I will be wearing my Bluetooth HRM, which connects to my iPhone, and I will be using the CardioCoach App which has my HR zones from my metabolic test. Metabolic Testing? What’s that?
Many serious endurance athletes will still opt for a chest strap and wrist unit that provides a lot of the analytics and data that endurance athletes thrive on. For the rest of us, a bluetooth chest strap that works with an app on your phone will probably do the trick and save you some money. Most bluetooth HR chest straps are less than $100.
For my dad, a former serious endurance athlete himself that still goes to the gym three times a week and does cardio and resistance training, I recommend the Polar H10 strap for $89.95.
Since Dad is not running the trails and roads anymore but sticking inside on cardio equipment, using his phone during a workout should be not be hassle. If he finds he does not want to take his phone with him into the gym area (he does pretty well on his phone but he is not as attached as a young millennial) then he can try the Garmin Forerunner 25 bundle. It has a chest heart rate strap and when you are just using it as a watch it tracks your steps and activity.
If you are just looking to track your steps and your activity, go with an Activity Tracker, like a a FitBit. If you are looking to track steps, activity, and your HR I recommend a chest strap for monitoring your HR. You can still use your Apple Watch, or your FitBit that you wear on your wrist, but I would not recommend using these tools to monitor your HR.