Use of CR100 scale for session-RPE in soccer and interchangeability with CR10

Purpose: To examine the construct validity of the session rating perceived exertion (s-RPE) assessed with the Borg CR100® scale to measure training loads in elite soccer and to examine if the CR100® is interchangeable and can provide more accurate ratings compared to the CR10® scale. Methods: Two studies were conducted. The validity of the CR100® was determined in 19-elite soccer players (age 28 ± 6 y, height 180 ± 7 cm, body mass 77 ± 6 kg) during training sessions through correlations with Edwards heart rate method (study one). The interchangeability with CR10® was assessed in 78 soccer players (age 19.3 ± 4.1 y, height 178 ± 5.9 cm, body mass 71.4 ± 6.1 kg) through Bland?Altman method and correlations between change scores in different sessions. To examine whether the CR100® is more fine graded than the CR10®, the proportion of responses corresponding to the verbal expressions were calculated (study two). Results: Individual correlations between Edwards' and s-RPE were large to very large (0.52 to 0.85). The mean difference between the two scales was -0.3 ± 0.33 AU (90% CI -0.41 to -0.29 AU) with 95% limits of agreements 0.31 to -0.96 AU. Correlations between scales and between changes scores were nearly perfect (0.95 and 0.91 to 0.98). Ratings corresponding to the verbal anchors were 49% in CR10® and 26% in CR100®. Conclusions: The CR100® is valid for assessing the training load in elite soccer players. It can be used interchangeably with the CR10® and may provide more precise measures of exercise intensity.