If you are used to measuring your physical effort during exercise by monitoring your heartbeat, you will probably notice certain changes during your pregnancy. Heart rate can be influenced by many factors, such as dehydration, fatigue levels, outside temperature, the time of day, ingestion of stimulants (e.g.: caffeine), and an increase in blood volume that occurs during pregnancy.
Targeted heart rate during pregnancy
The chart below illustrates the percentage of desired intensity for a physical activity according to maximum heart rate. Maximum heart rate (MHR) is the number of beats per minute that you can achieve during a very high-intensity exercise, for example during an intense effort of one to two minutes. A heart rate measurement test is very demanding and should never be done during pregnancy. You can estimate your heart rate by using the following formula*: MHR = 208 - (0,7 x age).
The following chart presents data for women who have no major health problems. The efficiency of the cardiovascular system varies from one person to another; therefore, actual heart rate may vary for the same intensity level.