title: Movement and Physiological Demands of Australasian National Rugby League Referees.
abstract: OBJECTIVE
  To evaluate the movement and physiological demands of Australasian National Rugby League (NRL) referees, officiating with a 2-referee (ie, lead and pocket) system, and to compare the demands of the lead and pocket referees.
  
  
  METHODS
  Global positioning system devices (10 Hz) were used to obtain 86 data sets (lead, n = 41; pocket, n = 45) on 19 NRL referees. Total distance, relative distance covered, and heart rate per half and across match play were examined within and between referees using t tests. Distance, time, and number of movement "efforts" were examined in 6 velocity classifications (ie, standing <0.5, walking 0.51-2.0, jogging 2.01-4.0, running 4.01-5.5, high-speed running 5.51-7.0, and sprinting >7.0 m/s) using analysis of variance. Cohen d effect sizes are reported.
  
  
  RESULTS
  There were no significant differences between the lead and pocket referees for any movement or physiological variable. There was an overall significant (large, very large) effect for distance (% distance) and time (% time) (P < .001) between velocity classifications for both the lead and pocket referees. Both roles covered the largest distance and number of efforts at velocities of 0.51-2.0 m/s and 2.01-4.0 m/s, which were interspersed with efforts >5.51 m/s.
  
  
  CONCLUSIONS
  Findings highlight the intermittent nature of rugby league refereeing but show that there were no differences in the movement and physiological demands of the 2 refereeing roles. Findings are valuable for those responsible for the preparation, training, and conditioning of NRL referees and to ensure that training prepares for and simulates match demands.
authors.forename: Amy
authors.initials: A
authors.lastname: Brightmore
authors.forename: John
authors.initials: J
authors.lastname: O'Hara
authors.forename: Kevin
authors.initials: K
authors.lastname: Till
authors.forename: Steve
authors.initials: S
authors.lastname: Cobley
authors.forename: Tate
authors.initials: T
authors.lastname: Hubka
authors.forename: Stacey
authors.initials: S
authors.lastname: Emmonds
authors.forename: Carlton
authors.initials: C
authors.lastname: Cooke
mesh_terms: D000328:Adult; D001315:Australia; D000072599:Cardiorespiratory Fitness; D005538:Football; D040362:Geographic Information Systems; D006339:Heart Rate; D006801:Humans; D007587:Job Description; D007590:Jogging; D008297:Male; D009043:Motor Activity; D012420:Running; D013997:Time Factors; D013996:Time and Motion Studies; D016138:Walking; D000066477:Work Performance
keywords: heart rate; intermittent physical demands; match demands; match officiating; time–motion analysis