Fitness trackers help tailor workouts

If you wear a smartwatch or fitness tracker, you have access to data about your heart health.

Beyond basic heart rate monitoring, smartwatches and fitness trackers also can measure and track heart rate zones, heart rate variability and heart rate trends. To make the data useful, Kathryn Larson, a cardiologist at the Sports Cardiology Clinic at the Mayo Clinic in Rochester, asks patients about their health and fitness goals.

“The discussion changes a lot based on what that patient or athlete wants to do with that data,” she said.

For people looking to develop an exercise habit, heart rate data can be a great tool for understanding how their fitness levels change. For more-experienced athletes, heart rate zone training can help improve speed and endurance.

To measure your heart rate without a wearable device, find your pulse in your neck or wrist. Count the number of beats detected in 15 seconds and multiply that number by four.

Your resting heart rate is the number of times your heart beats in a minute when you are not exerting yourself. Your maximum heart rate is a measure of how fast your heart beats during intense exercise.

A healthy resting heart rate is typically between 60 and 100 beats per minute. Athletes and people with high fitness levels often have lower resting heart rates.

“The best way to really understand zones is by understanding the effort, and the purpose,” said Dr. Tamanna Singh, a cardiologist and co-director of the Sports Cardiology Center at Cleveland Clinic.

Zone 1 is comparable to a warm up or a cool down. You should be able to “sing a song or recite a Shakespearean sonnet without interruption,” Singh said.

Zone 2 should be slightly more challenging. You should be able to hold a conversation, but you might need a breath here and there. During endurance sports such as running and cycling, most of your training time should be spent in this zone.

Zone 3 might require taking more breaks between conversations. Many runners refer to this effort level as “tempo” pace.

Zone 4 is what runners and cyclists call a threshold workout, “something you could probably sustain for maybe 45 minutes or an hour max,” Singh said.

Many factors — stress, weather and sleep, for example — can impact your heart rate, so it’s important to consider your own sense of effort alongside your heart-rate readings.

Many wearable devices also calculate the wearer’s heart rate variability, or HRV. The measurement tracks how your heart rate naturally fluctuates from beat to beat. It can be used to monitor how recovered or fatigued you are between workouts.