Energetic Demands Of Interchange And Full-Match Rugby League Players

Cummins C, Gray A, Shorter K, Halaki M, Orr R

The purpose of this study was to describe and compare the metabolic demands of rugby league for interchange and full-match players in relation to positional groups. Eighteen elite rugby league players were recruited. A time-motion model was used to estimate the energy expenditure and metabolic demands of rugby league match-play utilizing Global Positioning System (GPS) technology. This approach utilizes players’ GPS velocity-time curves to examine running velocity. Players were categorized into positional groups (outside backs, adjustables, wide-running, and hit-up forwards) and then further categorized into full-match or interchange players.

Compared to their full-match counterparts, interchange wide-running forwards expended greater energy (43.1±6.1 vs 28.6±7.5 kJ·kg⁻¹, p≤ 0.001, ES=-2.38) and produced a higher anaerobic index (p=0.016, ES=0.56) and mean power (7.4%, p=0.003, ES=0.66) per match. Full-match adjustables expended 94.8% more energy (p≤ 0.001, ES=-2.3) and performed more moderate accelerations (10.1%, p=0.014, ES=-0.57) and decelerations (7.6%, p=0.017, ES=-0.8) than their interchange counterparts. Outside backs did not interchange and hit-up forwards rarely (n=2) played an entire match. Differing metabolic demands were identified for interchange and full-match players across positional groups, suggesting position-specific conditioning drills are required to model the energetic demands of match-play.