Your heart rate isn’t just a record of your heart’s pumping action; it’s also an indicator of your overall health. Each muscle contraction is a complex electrical process to conduct blood, oxygen, nutrients, and more throughout the body. Used by doctors, heart patients, athletes, and even school gym teachers, heart rate monitors inform users — and their health team — just how well the heart is working at rest and when it is challenged. Luckily for all of these groups, measuring and recording your heart rate is easier to do than ever before, with a little training.
The traditional way to measure the heart rate and rhythm (its contraction pattern) is with an electrocardiogram (EKG) machine, lying down at rest. In the 1940s, the Holter monitor emerged as a portable EKG: a device that could give highly accurate, continuous heart rate details during activity. This first heart rate monitor eventually shrunk to today’s wristwatch size but otherwise remains similar to the original, using a chest strap to detect the heart’s electrical activity.
Other types of heart rate monitors
Holter straps are the traditional way to record heart rates, but they aren’t the only option.
Wrist monitors, focused solely on heart rate (like Polar) or as part of an overall health tracker (like Fitbits), are increasingly popular. These monitors use an optical sensor to detect the pulsation at the radial (wrist) artery. Advantage is an easy snap-and-go option with good accuracy, and automatic recording.
Similarly, pulse oximeters are an older but still reliable way to use optics to learn your heart rate and blood oxygen levels through finger artery pulses. Pulse ox devices are small, cordless, and relatively affordable. However, their accuracy drops during strenuous exercises (for example, with heart rates over 155 beats per minute).
The latest advance in optic measurement, which anyone can use almost anywhere, is a smartphone pulse detection app. Like pulse oximeters, smartphones use a pulse detected in the index finger, but with the camera’s flash as an aid. Apps offer fast and often free results that record the rate, potential rhythm changes, and waveforms. Unlike Holters, though, these apps use photoplethysmograph (PPG) waves, not an EKG, to graph the heart rhythm by sensing changes in blood flow. Research so far supports an accuracy of about 80 percent to 99 percent with PPG waves compared with EKG measures, so these apps likely will continue to increase in quality and become an accessible way for professionals to discuss heart rhythm with patients.
Do you need a heart rate monitor?
The risk of rhythm problems, like atrial fibrillation, increases after a cardiac event or surgery. Although heart rate alone can’t diagnose these problems, it can be a sign to your doctors about possible rhythm changes. Monitoring during cardiac rehab and after helps you exercise safely and cool-down completely.
What if you don’t have a heart condition? Tracking your heart rate is still a great guide to optimal cardiac muscle exercise. Your heart gets the most from workouts within a target heart range and below your individual peak rate. It’s good to know your resting heart rate (when you are sitting quietly) first. The target and maximum rates are health- and age-based percentages of this resting rate. If you are not entirely healthy, or if you just need help with the measures, ask your doctor or nurse to calculate a heart rate goal for you.
Which monitor is right for you?
Choosing a monitor depends on who you are. Are you a performance athlete who aims for high-intensity training? Chest straps or wristwatches offer continuous monitoring with comfort and accessibility. Are you a recovering heart patient who has a target range for exercise? Accuracy is vital, but chest straps may still be uncomfortable. Maybe the pulse oximeter is right for you. Or are you simply looking proactively at heart health? Perhaps an app that might lose some accuracy but can store trends is right for you.
And of course, there’s the oldest method ever, always free and portable: two-finger radial or carotid (neck) pulse detection. The bottom line on choice — the best monitoring method is the one that you’ll continue to use.
Nicole Van Hoey, PharmD, is a freelance writer and editor for consumer and professional health publications. She underwent open heart surgery in August, 2016, and writes about the experience, including cardiac rehab, for HealthCentral. She can be found on Twitter at @VHMedComm.