Abstract: Rodríguez-Marroyo, JA, Villa, G, García-López, J, and Foster, C. Comparison of heart rate and session rating of perceived exertion methods of defining exercise load in cyclists. J Strength Cond Res 26(8): 2249–2257, 2012—The aim of this study was to analyze the competition load using the session rating of perceived exertion (RPE) during different professional cycling races and to assess its validity using the competition load based on heart rate (HR). During 2 consecutive seasons, 12 professional cyclists (mean ± SEM: age 25 ± 1 years, height 175 ± 3 cm, body mass 65.9 ± 2.0 kg, and V[Combining Dot Above]O2max 78.5 ± 1.7 ml·kg−1·min−1) competed in 5-, 7-, and 21-day cycling races. The HR response and session RPE were measured during the races to calculate the competition load based on the training impulse of the HR (TRIMPHR) and RPE data (TRIMPRPE). The highest (p < 0.05) TRIMPRPE was observed in 21-day races. However, the higher (p < 0.05) TRIMPHR was found in 5- and 7-day races. When TRIMPHR and TRIMPRPE were normalized by competing distance, neither TRIMPHR·km−1 nor TRIMPRPE·km−1 was significantly different between the analyzed cycling races. We found significant (p < 0.001) correlations between TRIMPHR and TRIMPRPE (r = 0.75) and between TRIMPHR·km−1 and TRIMPRPE·km−1 (r = 0.90). In conclusion, this study showed that the session RPE can be used to quantify the competition load during professional cycling races. This method can be a useful and noninvasive tool for coaches to monitor and control the training load in cyclists.