How Popular Heart Rate Monitors Work

Heart rate monitors have become so readily available that you can buy them at your local drug store. Many models, however, don’t work well enough for you to track your heart rate accurately. While a $25 wristband from CVS might give you a rough estimate, it will make a lot of mistakes, too.

You can currently find three major types of heart rate monitors. Learn about each one to help you decide which model suits your needs best.

Chest Straps Use EKG Technology

When it comes to accuracy, chest straps almost always beat wristbands. Chest strap heart rate monitors essentially work like EKG machines. When your heart beats, it creates a small electrical signal. The signal is too small for you to notice, but chest strap sensors are designed to record them.

Electrocardiography offers the most accurate way to measure your heart rate while exercising. You do, however, have to place the sensor on your skin. Some people find that chest straps become uncomfortable during strenuous exercise. Other than using a wristband, there isn’t much you can do about the discomfort.

Wristbands Use Light to Measure Blood Flow

Wristband monitors rarely work as well as chest straps, but they’re comfortable and convenient to use. Instead of strapping something onto your chest, you just wear the monitor like a wristwatch.

Most wristband monitors use a version of photoplethysmogram technology to measure your heart rate. Photoplethysmogram is the technical word for shining light into capillaries and measuring the result. The wristband’s sensors detect how much light penetrates the capillaries and use an algorithm to give you an estimate of your heart rate. It’s not perfect, but it works pretty well.

Unfortunately, wristband monitors have one big problem: you have to stay still for them to work. If you’re running, doing yoga, or lifting weights, it will not give you an accurate result. In fact, the device will probably refuse to give you any result at all.

Ear Buds Listen to Your Heart Rate

Wristbands and chest straps have been around for several years. More recently, a few companies developed ear buds that can listen to your heart rate while you play music. The ear buds have built-in sensors that measure the thud, thud that you hear when you’ve been exercising vigorously. If you stick a fingertip in your ear, you can listen to your heart thumping. The ear buds function in a similar way.

The downside to ear buds is that they have limited battery lives. Most of them are comfortable, and they work well, but you can’t get more than five hours of use before the battery dies. That amount of time is fine for most people, but serious athletes may find it limiting during training season.

No matter what type of heart rate monitor you choose, you’ll likely need a compatible smartphone to use all of its features. Make sure you choose a model that works with your mobile device. If you choose a monitor that won’t connect properly, you’ll only get a limited amount of information from it.

Image via Flickr by aperturismo