The use of a fixed value of RPE during a ramp protocol. Comparison with the ventilatory threshold.

BACKGROUND: The purpose of our investigation was to assess the use of a fixed value (12-13) of the Rating of Perceived Exertion (RPE) scale (6-20) as a valid method for the determination of the workload corresponding to the ventilatory threshold (VT) during a ramp protocol on a cycle ergometer. METHODS: Eleven trained cyclists (22 +/- 3 years of age; VO2max: 65.2 +/- 12.4 ml.kg-1.min-1) were selected as subjects. DESIGN: Each of the subjects performed a ramp protocol on a cycle ergometer (starting at 25 W, with increases of 25 W.min-1 until exhaustion). Gas exchange data were analysed continually during the test to detect the ventilatory threshold (VT) of the subjects. In addition values of RPE were obtained from each subject in the last 15 sec of each 2-minute-interval during the tests, and immediately after exhaustion. The RPE threshold (RPET) was defined as a constant value of 12-13. Mean values of VT and RPET were expressed as VO2 (ml.kg-1.min-1), %VO2max, heart rate (bpm) and power output (W), and were compared using a paired "t"-test. RESULTS: No significant difference (p < 0.05) was found between mean values of VT and RPET, when both parameters where expressed either as VO2, %VO2max, heart rate, or power output. CONCLUSIONS: In conclusion, a fixed value (12-13) of the RPE scale might be used to detect the exercise intensity corresponding to VT. Such parameter may therefore be used for exercise prescription in substitution to more sophisticated methodologies.