Use of ratings of perceived exertion to anticipate treadmill test termination in patients taking beta-blockers.

This investigation identified a perceptually-based "warning zone" that can be used to anticipate termination of treadmill tests administered to individuals taking beta-blockers. The use of ratings of perceived exertion to anticipate test termination may be valuable given the attenuation of heart rate associated with the use of this class of medication. Sixteen men with coronary artery disease participated in this investigation. Ratings of perceived exertion (Borg 6-20 Scale) were estimated during the last 15 sec. of each minute of a progressively incremented treadmill test. Tests were terminated when participants indicated they were too fatigued to continue. The time-to-test termination was determined from the point that participants estimated a rating of 10, 11, 12, 13, 14, 15, 16, and 17 in order to determine the rating that was less than or equal to the time associated with a single exercise stage. A rating of 14 was associated with impending termination, which can be used as a "warning zone." The time to termination corresponding to a rating of 14 was 153.1 sec. (SD = 27.0). Participants exercised for 153.1 sec. (SE = 27.0) after estimating a rating of 14. Once a rating of 14 is reached, volitional test termination will occur before the next exercise stage is completed.