One way to gauge how hard you are exercising is to use the Borg Scale of Perceived Exertion. The Borg Scale takes into account your fitness level: It matches how hard you feel you are working with numbers from 6 to 20; thus, it is a "relative" scale. The scale starts with "no feeling of exertion," which rates a 6, and ends with "very, very hard," which rates a 20. Moderate activities register 11 to 14 on the Borg scale ("fairly light" to "somewhat hard"), while vigorous activities usually rate a 15 or higher ("hard" to "very, very hard"). Dr. Gunnar Borg, who created the scale, set it to run from 6 to 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.
| How you might describe your exertion | Borg rating of your exertion | Examples (for most adults <65 years old) |
| None | 6 | Reading a book, watching television |
| Very, very 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 that require moderate effort and speed your heart rate and breathing but don't make you out of breath |
| Hard | 15 to 16 | Bicycling, swimming, or other activities that take vigorous effort and get the heart pounding and make breathing very fast |
| Very hard | 17 to 18 | The highest level of activity you can sustain |
| Very, very hard | 19 to 20 | A finishing kick in a race or other burst of activity that you can't maintain for long |
Source: Borg G.A. Psychophysical bases of perceived exertion. Medicine and Science in Sports and Exercise. 1982; 14:377-381.
