Your heart operates as the pump that drives the delivery of oxygen and fuel throughout your body, while at the same time removing waste so that every system can operate at its best. Typically, your heart rate will elevate, pumping harder and more frequently, during exercise to meet the increased demands of your muscles. Occasionally, however, you could experience a sharp decrease in your heart rate. Depending on the surrounding circumstances, this may or may not be cause for concern.
Potential Good Signs
A drop in your heart rate could be a sign that you're making good progress toward your fitness goals. When your heart is stronger and more efficient, it's able to pump less frequently but with the same results. Usually, as your fitness level improves, you will experience a decrease in heart rate in the first few minutes of exercise.
This variation in your heart rate could be more or less noticeable depending on your style of training. If, for example, you're out for a steady-state run in which you're keeping the same pace the whole time, it's likely that your heart rate will stay within a small range. Interval training, however, where the pace changes drastically, is likely to result in much larger leaps in your heart rate.
If you experience a decrease in heart rate while exercising, though, it could be a cause for concern. This is especially true if you're being treated for heart disease or have undergone heart surgery in the past. Your heart could be struggling to meet the demands of your activity and slowing down as a result. Heart rate variations have a different pattern for heart patients than for healthy individuals; your doctor will be able to suggest future actions.
Warnings and Considerations
Other health conditions, including dehydration as well as endocrine, nervous system, kidney or liver dysfunctions, could also be associated with a decreased heart rate. As a precaution, it's wise to see your doctor before beginning any workout routine.