The relationship between differential and session ratings of perceived exertion with heart-rate derived measures of internal load in contemporary dance : an observational study

Abstract

BACKGROUND: The injury burden in dance is substantial and overuse injuries predominate. Training load is an important variable in understanding overuse injury aetiology and in the formulation of injury prevention strategies.

AIM: To investigate the application of differential (dRPE) and session ratings of perceived exertion (sRPE) in contemporary dance and to explore their relationship with objective measures of internal training load derived from heart rate in contemporary dancers.

DESIGN: Cross sectional observational design using field-based data collection.

METHODS: Using the centiMax ratings of perceived exertion, a convenience sample of 31 dancers were recruited from three companies (26 females, 5 males; [mean±SD] age = 21±2.6 yr, mean body weight 65.1±10.5 kg; total duration weekly dancing 28.3±7.9 h, mean session duration 28.3±7.9 mins, total weekly duration 28.3±7.9 h/week) and provided sRPE for dance classes and differential ratings for breathlessness (RPE-B), technical difficulty (RPE-T), arm exertion (RPE-A) and leg exertion (RPE-L) from 174 individual sessions. These RPE values were multiplied by session duration to calculate session training load, (sRPE-TL) and differential load values, (dRPE-T, dPRE-B, dRPE-A, and dRPE-L). Bannister’s and Edwards’ training impulse (TRIMP) were calculated from heart-rate recordings for all sessions. Data were analysed using magnitude based inferences.

RESULTS: Within-individual correlations between Bannister’s or Edwards’ TRIMP and differentials were respectively: sRPE-TL (r=0.38, r=0.41), dRPE-B (r=0.47, r=0.49), dRPE-A (r=0.39, r=0.41), dRPE-T (r=0.22, r=0.29) and dRPE-L (r=0.29, r=0.27). The strongest correlations were between dRPE-B and Bannister’s or Edwards’ TRIMP. Multiple linear regression revealed that a substantial proportion of variance (78%) in sRPE can be explained by RPE-L and RPE-B.

CONCLUSIONS: This study provides further evidence that dRPE represent different sensory input and different dimensions of effort such as those that arise centrally (RPE-B), those that arise peripherally (RPE-L, RPE-A) and those that are cognitive (RPE-T). The current findings demonstrate that dRPE-B is more indicative of the cardiovascular load pathway than sRPE-TL in contemporary dancers. For applied practitioners, dRPE-B provides a simple means to quantify and monitor cardiovascular load in dancers for use in their training management and in future injury prevention studies.