The use of session RPE for interval training in master endurance athletes: should rest be included?

AIM: The aim of this study was to evaluate the effectiveness of the session rate of perceived exertion (RPE) method as a tool to quantify internal training load during interval training in master athletes. In addition, we investigated whether it is appropriate to take into account rest periods when calculating the session-RPE. METHODS: Eight male master endurance athletes (age: 45.3±7.3 years; stature: 1.74±0.06 m; body mass: 64.9±9.1 kg) were monitored during an interval training session consisting of 5 x 1000 m performed at 95% of vVO2max with 5 min rest between bouts. Edwards' summated heart rate zone method was used as a reference measure and the session RPE rating was obtained using the CR10 Borg's scale modified by Foster. RESULTS: High (r: 0.82; R2: 0.67) and significant (P=0.013) correlation was observed between the Edwards' heart rate (HR) and the session-RPE method when rest periods are taken into account; meanwhile a higher significant correlation (r: 0.86; R2: 0.74; P=0.003) was found between Edwards' HR and the session-RPE methods when rest periods were eliminated for the session-RPE computation. CONCLUSION: Despite the rest period exclusion from the computation of session RPE seems more appropriate, the statistical analysis indicates that there is no significant difference between the two correlation coefficients. These findings suggest that the session-RPE can be a useful tool to monitor internal training load during interval training and that the inclusion/exclusion of rest periods in its computation needs further investigation.