Are rating of perceived exertion and heart rate methods useful to monitor the internal training load in functional training?

Abstract Aim: The study aimed to quantify and characterize the Training Load (TL) in a Functional Training (FT) model using Heart Rate (HR) and Session Rating of Perceived Exertion (sRPE) methods, and to verify whether these methods could be valid to monitor the TL during a FT program. Methods: The study design consisted of two phases: phase 1 - composed of a single training session of FT (FTSESSION), in which HR, sRPE, and pre- and post-exercise lactate [La] levels were assessed; phase 2 - composed of a FT program (FTPROGRAM) with eight weeks of duration and two sessions per week. The HR and SRPE were utilized to monitor all training sessions, and the results between sessions 1 vs. 8, 8 vs. 9, and 9 vs. 16 were compared. Results: On phase 1, HR distribution demonstrated that the participants spent about 75% of the total training time above 80% HRmax. Post-exercise [La] values were significantly higher (p < 0.05) than pre-exercise. The mean sRPE score was 8.5 ± 1.2. In phase 2, HR distribution was different between sessions 1-8 and 8-9 (p < 0.05). A strong correlation (r = 0.790) between the internal training load (ITL) and Training impulse (TRIMP) was observed. Conclusion: Our data demonstrated that the FTSESSION can be characterized as a high-intensity exercise, based on the pattern of HR responses and sRPE, and was reinforced by the [Lapeak]. Also, the TL monitoring methods (sRPE and TRIMP) proved to be valid for monitoring FT programs.