Home Fitness Cardiovascular Aerobic Training Calculating Heart Rate

Calculating Your Heart Rate


Cardiovascular System

Your heart rate is an actual measurement of the number of times your heart beats per minute, which is referred to as BPM.

An average human being at rest has a heart rate or HR of around 70 BPM (male adults) or 75 BPM (female adults).

The number of heart beats per minute is different for everyone and is due to several factors, including the following:

  • Age: Your heart rate changes as you age (it tends to slow down as you grow older)

  • Genetics: Some people are genetically predisposed to have higher or lower heart rates.

  • Current physical fitness: If you are overweight or consume a poor diet consisting of high levels of saturated fats and excess sodium, your heart rate can be higher.

warning

Warning!

There are other hidden causes of increased heart rate. Certain drugs and substances like caffeine can also increase heart rate, as well as emotions such as anger, fear, and anxiety. Finally, heart rate tends to increase with heat, like exercise or exposure to the Sun.

A person may be concerned about his or her heart rate for a variety of reasons. For example, if you are engaged in aerobic (or even anaerobic) training, you might like to know how close your heart rate is to your target heart rate, an important consideration to maximize training efficiency. Heart rate can also be measured by medical professionals as an indication of certain medical conditions. For instance, a resting heart rate of more than 100, known as tachycardia, can be an indication of an underlying condition such as anemia or hyperthyroidism.

What is Your Maximum Heart Rate?


Your maximum heart rate is the highest heart rate you can safely achieve during any period of exercise or stress, and varies depending on your age. The inverse of heart rate is R wave to R wave interval, as measured by an ECG and often denoted as RR.

Maximum heart rate can vary widely based on many factors. Children engaged in physical activity, for example, can have heart rates that exceed 200 BPM, a level that could be dangerous for older adults and the elderly. As you age, your resting heart rate will most likely decrease, as will your maximum heart rate.

Performing a maximal heart rate rest requires expensive equipment, and can be dangerous without the presence and assistance of a medical professional. Most people that begin an exercise routine can estimate their individual maximum heart rate using a mathematical formula.

Calculating Your HR Max


There are a variety of ways to measure maximum heart rate, the most accurate being a cardiac stress test, during which an individual is monitored by an ECG. During this test, exercise intensity is increased periodically until changes in heart function are evident. The test subject is then stopped and the ECG results are recorded. In total, this type of test can last up to twenty minutes.

To calculate maximum heart rate, a health professional can use the ECG and apply one of several calculations as follows:

  1. HR = 300 divided by number of large squares between R waves

  2. HR = 1,500 divided by RR interval in millimeters

  3. HR = 60 divided by RR interval in seconds

Of course, most people will not have access to a medical professional and ECG to constantly monitor heart rate, and it is unnecessary and impractical during most forms of physical activity. There are small commercial heart rate monitors available that consist of a chest strap and set of electrodes. These are preferred for measurements during physical activity, as even manual measurement during physical activity is difficult and will often yield inaccurate results.

Immediately following physical activity and during rest, you can monitor heart rate by finding your pulse in one of 13 major points of your body. A pulse rate is a measurement taken on any point where an artery's pulsation can be readily felt at the surface using your index and middle finger. Pulse is often taken by compressing an artery momentarily against a hard surface, such as a bone.

Although there are certainly other possible measurement points, the major areas where pulse measurement is possible on the human body include:

    Calculating Your Heart Rate
  • Radial Artery: The wrist (ventral aspect on the side of the thumb)
  • Ulnar Artery: Anterior and Medial Aspect of Wrist
  • Carotid Artery: Neck
  • Brachial Artery: Beneath the Bicep/Inside of Elbow
  • Femoral Artery: Groin
  • Posterior Tibial Artery: Feet/Behind Medial Malleolus
  • Popliteal Artery: Back of Knee
  • Abdominal Aorta: Above the Abdomen
  • Heart Apex: Chest
  • Superficial Temporal Artery: Temple
  • Facial Artery: Mandible (Lateral Edge)
  • Basilar Artery: Side of Head/Near Ear


Once you have accurately measure your pulse for your heart rate at rest, you can calculate your target heart rate, as well as use your maximum heart rate calculation to help you control your exercise intensity.

Below are the steps for a precise calculation. You can also use our Target Heart Rate Calculator if you don't want to perform the calculation manually:

  1. Subtract your age from 220. For example if you are 31, your answer will be 189.

  2. Multiply the result by 0.55, this will establish 55 percent of your maximum rate. Following the example you will multiply 189 x 0.55 which will give you 103.95, or 104 beats per minute. This will be the lower end of your exercise range, meaning the slowest rate that your heart should beat per minute during an exercise.

  3. Multiply the result from step 1 by 0.90. This process will calculate 90 percent of your estimated maximum heart rate. So in step 1 our answer was 189, the next thing to do is multiple this number by 0.90 this will give you 170.10, or 170 beats per minute. This will be the high end of your exercise. In other words, the fastest your heart should beat per minute during your exercise workout.

Regardless of the method you use to measure your heart rate during physical activity, doing so is important in making sure that your exercise is at maximum efficiency, especially when seeking an aerobic effect.

Heart Rate as a Risk Factor


Certain relatively recent studies have examined the link between increased heart rate as a risk factor for heart attack. One Australian study performed in 2008 included 11,000 patients from 33 countries around the world. A leader of the study, Ben Freedman - a professor of cardiology at the University of Sydney - stated that, following the test, they found that patients with a high heart rate were subject to a 46 percent increase in hospitalizations for heart attacks, both fatal and non-fatal. The study found that these patients with increased heart attack risk had a resting heart rate above 70 BPM.

Calculating Your Heart Rate

Other studies have established a link between faster resting heart rates in mammals and cardiovascular mortality rates. Increased resting heart rates also increase the production of certain molecules responsible for inflammation, along with regular mechanical stress within the heart. This link is only present in increased resting heart rates and is not associated with increased heart rates due to performing an exercise routine or any other form of physical activity.

Activities known to increase resting heart rate can also have adverse health effects. For example, lifestyle choices like nicotine use and regular intake of caffeine can increase your risk for a variety of diseases and adverse health conditions.

Increased resting heart rate is not always an indication of increased risk for heart attack. Heart rate can increase during the onset of a fever, for example.