title: Positional demands of professional rugby.
abstract: Rugby union is a physically intense intermittent sport coupled with high force collisions. Each position within a team has specific requirements which are typically based on speed, size and skill. The aim of this study was to investigate the contemporary demands of each position and whether they can explain changes in psychophysiological stress. Urine and saliva samples were collected before and after five selected Super 15 rugby games from 37 players. Total neopterin (NP), cortisol and immunoglobulin A were analysed by SCX-high performance liquid chromatography and enzyme linked immunosorbent assay. Global positioning system software provided distance data, while live video analysis provided impact data. All contemporary demands were analysed as events per minute of game time. Forwards were involved in more total impacts, tackles and rucks compared to backs (p < 0.001), while backs were involved in more ball carries and covered more total distance and distance at high speed per minute of game time (p < 0.01). Loose forwards, inside and outside backs covered significantly more distance at high speed (p < 0.01), while there was a negligible difference with number of impacts between the forward positions. There was also minimal difference between positions in the percentage change in NP, cortisol and sIgA. The results indicate distance covered and number of impacts per minute of game time is position-dependent whereas changes in psychophysiological stress are independent. This information can be used to adapt training and recovery interventions to better prepare each position based on the physical requirements of the game.
authors.affiliation: a School of Biological Sciences, Free Radical Biochemistry Laboratory , University of Canterbury , Christchurch , New Zealand.
authors.forename: Angus
authors.initials: A
authors.lastname: Lindsay
authors.affiliation: b Department of Life Sciences, College of Life and Natural Sciences , University of Derby , Derby , UK.|c School of Sport and Physical Education , University of Canterbury , Christchurch , New Zealand.
authors.forename: Nick
authors.initials: N
authors.lastname: Draper
authors.affiliation: d Steroid and Immunobiochemistry Laboratory , Canterbury Health Laboratories , Christchurch , New Zealand.
authors.forename: John
authors.initials: J
authors.lastname: Lewis
authors.affiliation: a School of Biological Sciences, Free Radical Biochemistry Laboratory , University of Canterbury , Christchurch , New Zealand.|e Department of Radiology , University of Otago , Christchurch , New Zealand.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Gieseg
authors.affiliation: f New Zealand Rugby Union , Wellington , New Zealand.|g School of Sport and Recreation, Sports Performance Research Institute New Zealand , Auckland University of Technology , Auckland , New Zealand.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Gill
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005538:Football / Q000502:physiology*; D040362:Geographic Information Systems; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis; D007070:Immunoglobulin A / Q000032:analysis; D019798:Neopterin / Q000032:analysis; D012463:Saliva / Q000737:chemistry; D055815:Young Adult
chemical_list: D007070:Immunoglobulin A; D019798:Neopterin; D006854:Hydrocortisone
keywords: Biochemistry; injury and prevention; team sports