Is It Normal for Your Heart Rate to Drop During Exercise?

Exercise temporarily boosts your blood pressure and heart rate. It’s one of the best ways to promote a healthy heart.

But if you experience a drop in your heart rate while exercising, it could be due to a serious underlying cardiovascular problem.

Over time, exercise allows the heart to work more efficiently, which will decrease your resting heart rate, reducing the load on your heart and improving overall cardiovascular health, explains Amar Shere, MD, a cardiologist with Atlantic Health System in Mount Arlington and Morristown, New Jersey.

“However, a sudden drop in heart rate while exercising could suggest a mild, temporary [issue] or more serious underlying cardiovascular condition, including issues with the electrical conduction system of the heart,” he says.

It’s important to consult your doctor about any drop in heart rate while exercising.

How Exercise Affects Heart Rate

When your heart expands and contracts, forcing blood through your veins and arteries, you can feel and count those pulses at places like your wrist or neck to know your heart rate.

It’s expected that your heart rate drops after exercise, and the fitter you are, the faster it lowers back to baseline. “A very athletic individual will likely notice that it takes more time for their heart rate to increase as they exercise and that their heart rate drops faster once they finish a workout,” says Jossef Amirian, MD, a cardiologist with Manhattan Cardiology in New York City.

Wearing a heart rate monitor or fitness tracker is a good way to monitor your heart rate during workouts, but if you experience a sudden drop, you’ll also likely experience physical symptoms.

Dr. Amirian says those symptoms might include:

• Dizziness or lightheadedness
• Fainting or loss of consciousness
• Fatigue
• Shortness of breath
• Chest discomfort
• Confusion or disorientation
• Palpitations

If you find that your heart rate isn’t dropping during a workout but simply isn’t increasing as you’d expect, that’s something else. “This is called chronotropic incompetence, which medical providers can test for,” Amirian says.

Causes of a Drop in Heart Rate During Exercise

There are a few potential causes of a heart rate drop during exercise. Some are more serious than others.

Vasovagal Syncope

“Syncope can also occur during times of strenuous exercise if the person is not adequately hydrated, triggering the vasovagal reflex,” Dr. Shere says.

People often faint when they experience vasovagal syncope, which can be dangerous mid-workout.

Bradycardia

However, physically active adults, including athletes, often have a resting heart rate slower than 60 beats per minute. And generally, the more you train, the slower your heart rate will be during exercise.

Stokes-Adams Syndrome and Sick Sinus Syndrome

The chances of having either of these syndromes increases with age, particularly over 60. The abnormal heart rhythms of both syndromes can be dangerous. If you suspect you have either, see your doctor for an evaluation.

Prevention and Treatment of Drop in Heart Rate During Exercise

“Staying hydrated, optimizing electrolyte intake, and avoiding too much heat are all important for a healthy heart rate response during physical exercise,” Amirian says.

If you have bradycardia or vasovagal syncope, you may not need any treatment unless you experience prolonged or repeated episodes, in which case your doctor may give you medication or implant a pacemaker.

“Underlying conditions that may cause bradycardia are not limited to heart issues,” Amirian says. “They include thyroid dysfunction and tick-related illnesses such as Lyme disease. Many times the treatment of the bradycardia will focus on treating the underlying issue causing it.”

When to See a Doctor

Both Shere and Amirian agree that even one instance of a drop in heart rate warrants visiting a doctor.

“It is always advisable to see your medical provider if you experience a sudden drop in heart rate,” Amirian says. “They may or may not advise testing. However, they will likely obtain a history and do a physical exam to determine if further evaluation is warranted.”

Many times, a medical provider will work with you to make sure you’re optimizing all the potential ways to prevent a drop in heart rate in the future.

“For any isolated episode that raises questions or concerns, a healthcare professional should be consulted,” Shere says. “They can decide whether more evaluation is necessary to prevent subsequent events and potentially dangerous complications.”

The Takeaway

• Generally, exercise should cause heart rate to rise. The more vigorous the activity, the higher heart rate will rise.
• If heart rate falls during a workout, it can be a sign of a serious underlying condition. See a doctor about this, even if it happens just once.
• Heart rate dropping during exercise can be a symptom of vasovagal syncope, bradycardia, Stokes-Adams syndrome, or sick sinus syndrome.