Factors influencing perception of effort (session-RPE) during elite soccer training

Purpose: The aim of the present study was to identify the external training load markers that are most influential of session rating of perceived exertion (RPE) training load (RPE-TL) during elite soccer training. Methods: Twenty-two elite players competing in the English Premier League were monitored. Training load data (RPE and 10 Hz GPS integrated with a 100 Hz accelerometer) were collected during 1892 individual training sessions over an entire in-season competitive period. Expert knowledge and a colinearity r<0.5 were used initially to select the external training variables for the final analysis. A multivariate-adjusted within subjects model was employed to quantify the correlations between RPE and RPE-TL (RPE x Duration) and various measures of external training intensity and training load respectively. Results: Total high-speed running distance (HSR; >14.4 km·h-1), number of impacts and accelerations >3 m·s-2 remained in the final multivariate model (p<0.001). The adjusted correlations with RPE were r=0.14, r=0.09 and r=0.25 for HSR, impacts and accelerations respectively. For RPE-TL, the correlations were r=0.11, r=0.45 and r=0.37 respectively. Conclusions: The external load measures that were found to be moderately predictive of RPE-TL in soccer training were HSR distance, and the number of impacts and accelerations. These findings provide new evidence to support the use of RPE-TL as a global measure of training load in elite soccer. Furthermore, understanding the influence of characteristics impacting RPE-TL may serve to help coaches and practitioners enhance training prescription and athlete monitoring.