Your smartwatch can track a wide range of health data — including your resting heart rate. But what does that number actually say about your heart health?

According to the American Heart Association, a normal resting heart rate falls between 60 and 100 beats per minute (bpm). Well-trained athletes often have lower resting heart rates because their hearts are more efficient, says Dr. Vikas Sunder, a preventive cardiologist at the Cleveland Clinic. Certain medications, such as beta blockers, can also lower heart rate and affect how your body responds to stress.

If your resting heart rate is below 60 bpm and you are not an athlete, Sunder recommends consulting your healthcare provider. In addition, a resting heart rate above 100 bpm may signal that your heart is working harder than it should

“When your heart rate is elevated at rest, it can mean the organs are not efficiently extracting blood from the circulation, so the heart has to beat faster in order to push out more blood,” he explains. If your heart rate is consistently above 100 bpm you should consult your doctor.

Understanding Cardiac Output

Resting heart rate is only part of the picture. Another important measure is cardiac output — the amount of blood your heart pumps in one minute.

Cardiac output is calculated by multiplying heart rate (beats per minute) by stroke volume, the amount of blood pumped out with each heartbeat. This figure reflects how effectively your heart delivers oxygen-rich blood throughout your body. Stroke volume must be determined by your doctor — wearables do not measure it.

An efficient heart can pump more blood with each beat while maintaining a lower resting heart rate. This indicates a strong heart muscle and flexible blood vessels, allowing your body to get the oxygen and nutrients it needs without overworking the heart.

“Your cardiac output is a sign of how efficiently your heart is pumping,” Sunder explains. “When you need more oxygen — for example, when you are exercising — can your heart supply it? An efficient heart is pretty good at speeding up and slowing down when it needs to.

“Cardiac output is high and resting heart rate is low, because the heart does not have to beat fast to push blood out into the body,” Sunder says.

How to Lower Your Resting Heart Rate Naturally

Improving heart efficiency can help lower your resting heart rate over time.

• Exercise regularly. A combination of aerobic activity and resistance training strengthens the heart muscle and improves stroke volume. “When your heart becomes more efficient, your resting heart rate slows down,” says Sunder.

• Don’t obsess over the numbers. It’s normal for your heart rate to dip at night. During sleep, your body requires less oxygen, and your heart naturally slows down.

If you notice persistent changes in your resting heart rate or readings outside the normal range, discuss them with your healthcare provider.