why does your resting heart rate change
Causes of Heart Rate Changes. The heart rate is affected by different factors. According to MayoClinic.com, a normal heart rate is between 60 and 100 beats per minute. It is not uncommon for an athlete to have a resting heart rate between 40 to 60 beats per minute. A low resting heart rate may be indicative of a healthy cardiovascular system or it may signal the advent of heart disease. When the heart rate is over 100, it can be indicative of strenuous activity or illness.