Rate of Perceived Exertion or the Borg Rating of Perceived Exertion (RPE) is a way of measuring physical activity intensity level. In medicine, this is used to document the patient’s exertion during a test, and sports coaches use the scale to assess the intensity of training and competition.
The original RPE scale – A.K.A. Borg scale (6-20)
The original scale introduced by the Swedish psychologist Dr. Gunnar Borg, rated exertion on a scale of 6-20; as a simple way to estimate heart rate—multiplying the Borg score by 10 gives an approximate heart rate for a particular level of activity. It is based on the physical sensations a person experiences during physical activity, including increased heart rate, increased respiration or breathing rate, increased sweating, and muscle fatigue.
The seemingly odd range of 6-20 is to follow the general heart rate of a healthy adult by multiplying by 10. For instance, a perceived exertion of 12 would be expected to coincide with a heart rate of roughly 120 beats per minute.
|How you might describe your exertion||Borg rating||Examples (for most adults under 65 y.o.)|
|None||6||Reading a book, watching television.|
|Extremely light||7 to 8||Tying shoes.|
|Very light||9 to 10||Chores like folding clothes that seem to take little effort.|
|Fairly light||11 to 12||Walking through the grocery store or other activities that require some effort but not enough to speed up your breathing|
|Somewhat hard||13 to 14||Brisk walking or other activities (like riding a bike at an easy pace) that require moderate effort and speed your heart rate and breathing but don’t make you out of breath.|
|Hard||15 to 16||Activities that take vigorous effort and get the heart pounding and make breathing very fast. Like climbing with a bike at a moderate pace.|
|Very hard||17 to 18||The highest level of activity you can sustain: like time-trialing or climbing with a bike at your highest sustainable pace.|
|Extremely hard (Maximum exertion)||19 to 20||A finishing kick in a race or other burst of activity that you can’t maintain for long.|
The simplified RPE scale (0-10)
The Borg scale is good to follow but it’s a little clumsy using the numbers 6 through 20. There are other RPE scales based on the Borg scale, one common version uses a simplified scale of 0 to 10:
|How you might describe your exertion||rating||Examples (for most adults under 65 y.o.)||HR%|
|None||0||Reading a book, watching television.||0|
|Extremely light||1||Tying shoes||20-30|
|Very light||2||Chores like folding clothes that seem to take little effort||30-40|
|Moderate||3||Walking through the grocery store or other activities that require some effort but not enough to speed up your breathing||40-50|
|Somewhat hard||4-6||Brisk walking or other activities (like riding a bike at an easy pace) that require moderate effort and speed your heart rate and breathing but don’t make you out of breath.||50-70|
|Hard||7-8||Activities that take vigorous effort and get the heart pounding and make breathing very fast. Like climbing with a bike at a moderate pace.||70-80|
|Very hard||9||The highest level of activity you can sustain: like time-trialing or climbing with a bike at your highest sustainable pace.||80-90|
|Extremely hard (Maximum exertion)||10||A finishing kick in a race or other burst of activity that you can’t maintain for long.||90-100|
 How to calculate your heart rate percentage? First you have to learn your resting and maximum heart rates. Then we can calculate P% of heart rate as below:
HR = min. heart rate + ((Max. heart rate – min. heart rate) x P / 100)
Let’s assume that your max. heart rate is 180 and resting heart rate is 60. We can calculate 80% heart rate as:
HR = 60 + ((180 – 60) x 80 / 100) = 156
Your heart rate at 80% should be 156. The formula gives your min. heart rate at 0%, and your max. heart rate at 100%.
- Borg Scale on Wikipedia
- Centers for Disease Control and Prevention
- The Borg Scale of Perceived Exertion on Harvard School of Public Health website