Physical demands of international lead rugby union referees

The aim of this case study was to examine the speed and distance demands of lead rugby union referees, during the 2011 rugby world cup and compare this to existing data from elite players, and sub-elite referees. Global positioning system data was collected during 19 matches from the 2011 rugby world cup from 4 male professional rugby referees. The standardised differences and associated effect sizes (ES) were calculated for the total distance and the distance travelled in six different speed zones. The referees covered more distance than the sub elite referees, with large differences in total distance and ‘jogging’ (6.1-12.0 km/h); moderate differences in ‘medium’ (14.1-18.0 km/h) and ‘high’ (18.1-20 km/h) intensity run; small differences in ‘walk’ (0.1-6.0 km/h) and ‘low’ intensity run (12.1-14.0 km/h); and a trivial difference in ‘sprint’ (≥20.1 km/h). The referees covered more distance than the profession players, with an extremely large differences in ‘stride’ (13.7-18.0 km/h); very large differences in ‘cruise’ (9.7-13.7 km/h) and ‘high’ (18.0-19.8 km/h) intensity run as well as total distance covered; a large difference in ‘jog’ (5.8-97. km/h); a moderate difference in ‘sprint’ (>19.8 km/h); and a trivial difference in ‘walk’(0-5.8 km/h km/h). The information presented can help inform conditioning coaches that target speed zones up to sprinting (greater than 20 kmhr -1) and distances within the zones reaching up to 7400m need to be considered when developing specific programs for international lead rugby referees. Further, based on the data analysed in this study, rugby referees require a specific prescription of physical activity to meet the extra speed and distance demands compared to both professional rugby players and sub-elite rugby referees.