Table 2. Definitions of variables from the metabolic power concept. Variable Unit Definition Metabolic work J/kg Accumulated metabolic power over time Equivalent distance m Metabolic work divided by the energy cost of constant speed running (3.6 J/m) Equivalent distance index % Equivalent distance divided by total distance Time spent running % Time the Metabolic power model detects running divided by time on court Energy spent running % Metabolic work while the Metabolic power model detects running divided by total metabolic work Time over 10/20 W min Total time spent while metabolic power is higher than 10/20 W.