Low Heart Rate During Exercise: Understanding Bradycardia
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What to Do About a Low Heart Rate During Exercise

What to Do About a Low Heart Rate During Exercise
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Updated on July 31, 2025
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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 the 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

Your maximum heart rate is the number of times your heart beats per minute while at your highest exercise capacity.

 However, as Dr. Singh points out, you only want to reach what's called your target heart rate — 60 to 80 percent of that number. Also, this range gradually lowers with age.

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.

Increasing your heart rate during exercise is the best way to improve your heart strength and lower your risk of a heart attack.

 If you exercise a lot and are in excellent physical shape, it will take more exercise to get to your target range. If you're new to exercise, your heart rate will increase quickly with less exercise.

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."

Doctors define bradycardia as a heart rate of less than 60 beats per minute. However, even a heartbeat as low as 40 may be normal for very fit people, such as trained athletes. Bradycardia doesn't always cause symptoms. For other people, though, a heart rate under 60 could be a problem, especially if you have the following symptoms:

  • 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 Dr. Singh. "They may get worse during exercise."

Keep in mind, however, that your resting heart rate and heart rate while sleeping will naturally be lower than your exercise heart rate.

What Causes Bradycardia?

Bradycardia is more common in older adults with heart damage, such as from a heart attack or heart surgery, for instance. Infections of the heart — called myocarditis — can also cause bradycardia.

 "Other common causes include an underactive thyroid gland and medications that slow the heart, like some blood pressure or heart medications," says Dr. Singh.
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. From there, electrical signals travel down to the lower chambers of your heart to trigger heartbeats. Issues with your heart's electrical system can cause your heartbeat to slow.

Sinus node problems leading to a slow heartbeat can cause complications, but only if they're severe enough to trigger symptoms and you don't receive treatment for them.

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 Dr. Singh.

Get help right away or call 911 if you pass out during exercise or if you have chest pain and shortness of breath. Your doctor can do tests to find the cause of bradycardia and get you on the right treatment.

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.
EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. Target Heart Rates Chart. American Heart Association. August 12, 2024.
  2. What is a normal heart rate? Harvard Medical School. June 13, 2023.
  3. Bradycardia. Mayo Clinic. December 13, 2024.
  4. Sinus Bradycardia. Cleveland Clinic.
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Chung Yoon, MD

Medical Reviewer
Castle Connolly Top Doctor
Chung Yoon, MD, is a noninvasive cardiologist with a passion for diagnosis, prevention, intervention, and treatment of a wide range of heart and cardiovascular disorders. He enjoys clinical decision-making and providing patient care in both hospital and outpatient settings. He excels at analytical and decision-making skills and building connection and trust with patients and their families.
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Chris Iliades

Chris Iliades, MD

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Chris Iliades, MD, is a full-time freelance writer based in Boothbay Harbor, Maine. His work appears regularly on many health and medicine websites including Clinical Advisor, Healthgrades, Bottom Line Health, HeathDay, and University Health News. Iliades also writes a regular blog for The Pulse, a website for fetal health and pregnancy.

Iliades is board-certified in Ear, Nose and Throat and Head and Neck Surgery. He practiced clinical medicine for 15 years and has also been a medical director for diagnostic research and a principal investigator for clinical research before he turned to full-time medical writing.

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