(RPE). Table 15.3 lists his original and revised scales The original scale used the rankings 6 to 20 to ap- proximate the HR values from rest to maximum (60-200). The revised scale represents an attempt to provide a ratio scale of the RPE values. The RPE scores can be used as indicators of subjective effort and provide a quantitative way to track a person's progress through a GXT or an exercise session (21, 23, 44). This is helpful in knowing when a subject is approaching exhaustion, and the values can be used to predict VO2 max (35) and prescribe exercise intensity (see Chap. 16). However, large between subject variability in RPE ratings have been noted at the same heart rate, suggesting caution in using the scales (2). What follows is a suggested statement
from the ACSM Guidelines to read to the subject before testing (3) (p. 78)
During the exercise test we want you to pay close attention to how hard you feel the ex- ercise work rate is. This feeling should reflect your total amount of exertion and fatigue, combining all sensations and feelings of physi- cal stress, effort, and fatigue. Don't concern yourself with any one factor such as leg pain, shortness of breath, or exercise intensity, but try to concentrate on your total, inner feeling of exertion. Try not to underestimate or overes- timate your feeling of exertion; be as accurate as you can