An investigation into the sensitivity of differential ratings of perceived exertion (dRPE) as a tool to measure internal training load in team sport players

Abstract

Monitoring the internal response to training load in team sports has the potential to improve performance and reduce the risk of injury. A solution to monitor the internal load of individuals is to collect a subjective rating of perceived exertion (RPE). However, RPE may be theoretically limited by its approach in combing a variety of inputs into one gestalt score. To overcome this limitation, recent advances in monitoring have led to the development of a differential rating of perceived exertion (dRPE) which has the potential to provide a more sensitive evaluation of internal load. The aim of the current study was to investigate the ability of dRPE to detect changes in the physiological demands associated with different deceleration profiles in high-intensity running protocols. Thirteen male team sport players completed four exercise protocols (Dec5m, Dec15m, Dec5/15m and Dec15/5m) which involved 20 repetitions of a 30 metre high-intensity run but with different deceleration profiles. Ratings of muscular exertion (RPE_L) and feelings of breathlessness (RPE_B) were recorded after every repetition. In addition to dRPE the external load of the protocols was measured using 10 Hz GPS devices (Optimeye S5, Firmware 7.38, Catapult Sports, Melbourne, Australia) and measures of muscle soreness and neuromuscular fatigue were assessed. Total distance (p = 0.615) and average maximum velocity (p = 0.360) was consistent between the protocols. Peak deceleration was greater in the Dec5m protocol compared to the Dec15m protocol (p = 0.005). Changes in RPE_L and RPE_B increased substantially from the first to the last repetition during all the protocols. However, the rate of change in RPE_L and RPE_B from the first to the last repetition between the protocols ranged from likely trivial to most likely trivial. Comparisons of neuromuscular function measures were unclear for most of the time points. There was a very likely increase in muscle soreness in the Dec5m protocol compared to the Dec15m protocol 48 hours post protocol. In conclusion, dRPE might not be a sensitive enough measure to detect small differences in the muscular and respiratory demands of the protocols and cohort used in this study. However, the lack of sensitivity may be exercise/sport and/or population dependant.