Faster is not always better, especially in regard to your resting heart rate.  When you think of risk factors for heart disease, conditions such as diabetes, obesity, high blood pressure, and abnormal cholesterol profiles readily come to mind.  But, did you know that having an elevated heart rate at rest can increase your risk too?  A Norwegian study published online earlier this year in the Journal of Epidemiology & Community Health found that a faster resting heart rate was associated with a greater risk of death from a heart attack, especially for women.

The study followed over 50,000 apparently healthy adults (24,999 men and 25,089 women) for approximately 18 years (onset of the study occurred between 1984-1986 with the investigation ending in 2004).  For women under the age of 70 years, data indicated that the risk of death from heart disease increased by 18% for every 10 beat increase in resting heart rate.  There was no such relationship in women over the age of 70 years.  Men of all ages experienced an approximate 10% increase of risk (for death from a heart attack with every 10 beat rise in resting heart rate values.

The results of the investigation also indicated that participation in physical activity was associated with a lower risk of death from a heart attack in women who had high resting heart rates, but not for men with elevated resting heart rate values.  The researchers state that this discrepancy could be related to the fact that the subjects' exercise levels were self-reported, and that men are more likely to overestimate their levels of physical activity than are women.

What is a normal resting heart rate?  For most apparently healthy adults, a range of 60-80 beats per minute is typical.  Highly-trained individuals, such as marathon runners, may have resting heart rates that range from 40-60 beats per minute.  Resting heart rate values that are 100 beats per minute and above are classified as tachycardia; and, in the present study, these resting heart rates were associated with a 73% greater risk of death from a heart attack in men.  For women subjects under the age of 70 years with tachycardia, the risk of death from heart disease more than doubled.

What factors can influence resting heart rate values?

• Physical activity/fitness level
• Certain medications
• Environmental conditions (altitude, air temperature, humidity, etc.,)
• Stress/emotions
• Illness

How can you check (measure) your resting heart rate? Two common sites for locating your heart rate (pulse) are your wrist (radial pulse) and your neck (carotid pulse).

Radial Pulse Taking

Carotid Pulse Taking

• Radial Pulse:  Locate your pulse on your wrist at the base of your thumb by using your index and middle finger.  Count the number of beats for 15 seconds by counting the first pulse as zero (then 1, 2, and so on).  Multiply the total number of beats felt by 4 (for a 15 second period) to determine your heart rate in beats per minute.
• Carotid Pulse:  Locate your pulse on your neck to the side of your windpipe by using your index and middle finger.  Take care to not press on the other side of your windpipe at the same time, this can decrease blood flow to your brain.  Count the number of beats felt in a 15 second time period and multiply that value by 4 (as described above) to determine the total number of beats per minute. 

If you are concerned about your resting heart rate and/or you experience symptoms such as dizziness, lightheadedness, fainting, palpitations, and/or shortness of breath, etc., contact your physician for an evaluation.

Note:  Before beginning an exercise program or increasing the intensity level of a current routine, a physician's approval should be obtained, especially for older adults and those at risk for or who currently have chronic health conditions.


Resources:
J Epidemiol Community Health 2010;64:175-181, "Combined effect of resting heart rate and physical activity on ischaemic heart disease:mortality follow-up in a population study (the HUNT study, Norway)," Nauman, J. et al.

Reuters Health, "In women, exercise may keep high pulse in check," Joelving, F.

ACSM Fitness Book: A proven step-by-step program from the experts, third edition.