The present study assessed the effectiveness of an RPE learning protocol for improving the validity of the Borg 6-20 RPE scale for self-regulating exercise intensity during Indoor Cycling (IC). 16 healthy adults performed 5 IC sessions. Heart rate (HR) was continuously monitored. In sessions 1 and 5, participants perceptually regulated exercise intensity to produce pre-determined RPE levels equivalent to estimated HR levels. Sessions 2, 3 and 4 focused on the RPE learning protocol. The RPE-measured HR correlation was 0.59 in session 1 and 0.67 in session 5 (both P<0.001). The intraclass correlation coefficient between measured HR and estimated HR was 0.85 in session 1 and 0.90 in session 5. There was bias in session 1 (3.69 bpm [SD=12.44]; P<0.001) but not in session 5 (0.99 bpm [SD=9.7]; P=0.178; mean HR difference session 5 vs. 1: -2.70 bpm [95% CI: -4.49 to -0.91]; P=0.003; Cohen's d=0.24). There was association between the HR difference and the magnitude of the measurement in session 1 (beta=0.208; P<0.01) but not in session 5 (beta=-0.072; P=0.34). These preliminary results suggested that an RPE learning protocol might slightly improve the validity of the Borg 6-20 RPE scale for exercise intensity self-regulation during IC sessions in healthy adults.