What to Do About a Low Heart Rate During Exercise

When working out, you expect your heart rate to go up. In fact, increasing your heart rate during exercise is the best way to monitor your health and fitness level. But what if your heart rate stays low?

"Normally, when you exercise, you want your heart rate to get up to about 60 to 80 percent of your maximum heart rate," says Tamanna Singh, MD, a clinical cardiologist at Cleveland Clinic. "If your heart rate does not go up enough during exercise, or if it can't mount any response to exercise, you could have a heart problem."

Defining Maximum or Target Heart Rate

To find the target heart rate range for your age, subtract your age from 220 and then multiply that number by 0.6 and by 0.8 to see the low and high ends of the range. If you are 40 years of age, for example, this formula will indicate that your target range for healthy exercise is approximately 108 to 144 beats per minute.

When Is A Slow Heart Rate a Medical Problem?

"Bradycardia is the medical term for a resting heart rate that is less than 60 beats per minute," explains Dr. Singh. "There are two types. If you have a medical condition that slows down your heart rate, your heart may speed up during exercise, but not enough to reach the target range. If you have an abnormality of the electrical conduction system of your heart, your heart rate may not increase at all. Exercise could make you pass out."

• Extreme tiredness during exercise and physical activity
• Dizziness
• Shortness of breath
• Chest pain
• Confusion
• Memory issues
• Passing out

"These symptoms are warnings that your body and brain are not getting enough blood supply," says Singh. "They may get worse during exercise."

What Causes Bradycardia?

Additionally, electrical impulses that control your heartbeats originate in the right upper chamber of your heart, specifically in a natural pacemaker known as the sinoatrial node, also referred to as the sinus node.

When to Contact Your Doctor About Bradycardia

"If your pulse is below 60 most of the time, or if you get tired quickly during exercise and your pulse does not go up as expected, let your doctor know," says Singh.

The Takeaway

• If your heart rate does not increase as expected during exercise, it may indicate bradycardia, a condition in which the resting heart rate is below 60 beats per minute.
• Symptoms such as dizziness, chest pain, extreme fatigue, or fainting during physical activity may signal inadequate blood supply, warranting immediate attention and consultation with a healthcare professional.
• Bradycardia can be normal among well-trained athletes with strong heart health, but it may indicate underlying issues, such as heart damage or thyroid problems, in others. Understanding whether these are symptoms or natural variations requires a professional diagnosis.
• Seek immediate medical attention if you have shortness of breath and chest pain or faint often, as these can be serious signs of heart issues that need urgent treatment.