The rate of perceived exertion is a subjective manner of determining how hard a person perceives how hard he is working his body during physical activity. First developed by Swedish professor Gunnar Borg, the rate of perceived exertion centers on the physical sensations a person encounters while exercising, including increased heart rate, breathing rate, and muscle fatigue. The measure, originally based on a 20-point scale and later revised to a 10-point scale, can help provide an approximation of a person’s heart rate.
When first introduced, the rate of perceived exertion scale ranged from six to 20. Six was the low end of the scale, meaning virtually no effort was being produced. Conversely, 20 was the highest ranking for physical exertion. A person’s score determined whether he needed to increase or decrease activity.
With the six-to-20 scale, a person with a score of 12 or under was exercising at a light pace. This could be equated to walking slowly. A person with a score of 13 to 16 was performing somewhat heavy exercise. A score of 17 or more indicated an individual was pushing himself and working very hard.
The 0 to 10 rate of perceived exertion scale also measures how hard a person perceives he is working during exercise. A person with a score of 0 would not feel any exertion at all. This would be equated to a person sitting down. A person who gives himself a rating of 10 would be performing exercise at a difficult level.
With a score of one or two, the level of perceived exertion is considered very easy. Under this rating, a person is able to talk effortlessly. A score of three is perceived as easy and a person is able to talk with minimal effort. With a rating of four, the perceived exertion is fairly easy and an individual is able to talk at a comfortable level.
Under a rating of five, a person's exertion level is perceived as moderate and the individual needs some effort to talk. A rating of six indicates that an individual sees his effort as moderately hard and talking takes a concerted effort. If a person gives himself a rating of seven, he views he is working hard and will notice that talking requires a great deal of effort. A rating of eight means a person believes his exertion level is at a difficult level and will notice that talking requires a maximum effort. With a rating of nine or 10, a person views his exertion is at a maximum effort and is not able to talk.
With 10-point scale, a person can roughly calculate his maximum heart rate. Each level is multiplied by 10 determine a maximum heart rate. If a person's rate of perceived exertion was a five, that person would have obtained a maximum heart rate of 50 percent. The maximum heart rate is just an approximation, as it can vary depending on age and physical health.
