Match demands of Senior and Junior players during International Rugby League.Dempsey Gary M; Gibson, Neil V; Sykes, Dave; Pryjmachuk, Brad; Turner, Anthony PJournal of Strength & Conditioning Research: Post Acceptance: August 09, 2017 doi: 10.1519/JSC.0000000000002028 Original Research: PDF Only Abstract This study aims to quantify and compare the positional game demands of international junior and senior rugby league competition for the first time. Global Positioning System (GPS) and video analysis were used to track 118 elite male rugby league players (57 seniors aged 28.7 +/- 4.4 y; 61 juniors aged 17.2 +/- .5 y) over 10 international matches (6 senior; 4 junior) characterized as either forwards (n = 67) or backs (n = 51). There were significant increases in the offensive carries (0.18 cf. 0.09 n.min-1; r = .56) and defensive tackles (0.36 cf. 0.23 n.min-1; r = .3) between senior and junior players, as well as forwards and backs (0.16 cf. 0.09; r = .34 and 0.41 cf. 0.14; r = .52) respectively. Running demands were significantly greater in backs than forwards (independent of playing level) for total distance (6962 +/- 1263 m cf. 4879 +/- 1824 m; r = .55), individualized high speed distances (310 +/- 158 m cf. 250 +/- 171 m; r = .2), high-intensity accelerations (28.7 +/- 12.1 m[middle dot]s-1 cf. 21.9 +/- 11.7 m[middle dot]s-1; r = .27) and decelerations (57.2 +/- 18.3 m[middle dot]s-1 cf. 43.0 +/- 17.8 m[middle dot]s-1; r = .38). Positional differences were eliminated when reported relative to minutes played. From a practical perspective, whilst running demands relative to time on the pitch may prepare junior players for senior competition, it is not representative of the increased body mass and contact frequency within the senior game. Coaches should therefore reflect these differences within their physical preparation programmes to prepare junior athletes accordingly for progression to the senior level. Copyright (C) 2017 by the National Strength & Conditioning Association.