Low, moderate and high levels of exercise intensity, as measured by heart rate, are defined as follows:

  • Low (or Light) is about 40-54% MHR.
  • Moderate is 55-69% MHR.
  • High (or Vigorous) is equal to or greater than 70% MHR.

To calculate your MHR, please CLICK HERE TO VISIT another site.

For this example we will use a MHR of 170, then let's say your heart rate measured 100 beats per minute performing a certain activity.

Since 100 is approximately 59% of the MHR (170), that would be considered a moderate level of exercise.


Rating of Perceived Exertion
A simpler method than monitoring heart rate, which also corresponds with measured MHR, is the Rating of Perceived Exertion (or RPE).

RPE is measured by having a person rate how they feel (psychological perception) when performing an activity.

The ratings of physical effort and feelings correspond with heart rate, and people can learn to exercise at a desired level of intensity based on their subjective feelings of exertion. It should be noted, however, that people who have been previously inactive tend to overestimate their intensity level, especially for moderate activity.


Level of Intensity RPE Physical Cues
Light Easy Does not induce sweating unless it's a hot, humid day. There is no noticeable change in breathing patterns.
Moderate Somewhat hard Will break a sweat after performing the activity for about 10 minutes. Breathing becomes deeper and more frequent. You can carry on a conversation but not sing.
High Hard Will break a sweat after 3-5 minutes. Breathing is deep and rapid. You can only talk in short phrases.