Energetic and Metabolic Power Demands of National Rugby League Match-Play

The purpose of this study was to apply a timemotion model to estimate and describe the energy expenditure and metabolic power demands of playing positions in elite rugby league match-play, utilizing Global Positioning System (GPS) devices. 18 elite rugby league players participated in this study. Players' positional groups included: outside backs (n = 59 files, n = 4 players), adjustables (n = 74 files, n = 4 players), wide-running (n = 104 files, n = 7 players) and hitup forwards (n = 36 files, n = 3 players). Outside backs expended the greatest total energy (40.1 ± 5.0 kJ · kg⁻¹) per match, equivalent to 8.1 %, 26.6 % and 61.9 % greater energy than adjustables, wide-running and hit-up forwards, respectively. Adjustables attained an anaerobic index 7.3 % higher than wide-running forwards, 19.7 % higher than hit-up forwards (p = 0.001) and 43.2 % higher than outside backs (p < 0.001). Wide-running forwards achieved an anaerobic index (0.34 ± 0.04) 11 % and 32.8 % higher than hit-up forwards (p = 0.001) and outside backs (p < 0.001), respectively. Mean power of adjustables (10.0 ± 0.9 W.kg⁻¹) was significantly higher than all other groups (outside backs: 28.8 %, 7.8 ± 1.0; hit-up: 12.4 %, 8.9 ± 0.6; and wide-running: 8.7 %, 9.2 ± 0.7 forwards) (p < 0.001). Energetics indices indicated differing metabolic demands for all positional groups, suggesting position-specific conditioning drills are required to replicate the energetic demands of match-play.