Exercise boosts your blood pressure and heart rate temporarily and is one of the best ways to promote a healthy heart. But if you experience a drop in your heart rate while exercising, it could signify either a minor, temporary problem or a more serious underlying cardiovascular condition. Consult your doctor about any drop in heart rate while exercising.
Your heart rate, or pulse, is the number of times your heart beats per minute and is a way to tell how hard and effectively your heart is working. 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. If your resting heart rate is between 60 and 90 beats per minute, it's considered normal. Depending upon your age, the maximum heart rate you should experience during exercise can range from 150 to 200. If your heart rate drops too low during rest or exercise, it can lead to lightheadedness, fatigue and fainting, the National Emergency Medicine Association warns.
One of the most common causes of a drop in your heart rate while exercising is vasovagal, or neurocardiogenic, syncope, when blood vessels expand and blood pools in the lower parts of your body. This is often precipitated by overheating or dehydration, the Mayo Clinic explains. A heart arrhythmia called bradycardia can cause your heart to beat too slowly. This is usually a result of damage to the heart from a previous heart attack or heart disease. Adams-Stokes disease and "sick sinus syndrome" are two other conditions caused by a heart rhythm disorder that makes your heart rate slow down, the American Heart Association adds.
If you have bradycardia or vasovagal syncope, you may not need any treatment unless you experience prolonged or repeated attacks, in which case your doctor may give you medication or implant an artificial pacemaker. If your heart-rate drop is tied to overheating or dehydration, you should make sure to avoid exercising during the hottest parts of the day, dress appropriately and drink plenty of water before, during and after exercise.
If you find your heart rate is dropping on a regular basis during exercise, you should check with your doctor to determine if you have a heart arrhythmia or heart disease causing the problem. If you feel faint due to a drop in your pulse rate while exercising, the Mayo Clinic recommends that you stop immediately, lie down and lift your legs slightly until you recover, or put your head between your knees.