title: The Influence of In-Season Training Loads on Injury Risk in Professional Rugby Union.
abstract: OBJECTIVE
  To explore the association between in-season training-load (TL) measures and injury risk in professional rugby union players.
  
  
  METHODS
  This was a 1-season prospective cohort study of 173 professional rugby union players from 4 English Premiership teams. TL (duration × session-RPE) and time-loss injuries were recorded for all players for all pitch- and gym-based sessions. Generalized estimating equations were used to model the association between in-season TL measures and injury in the subsequent week.
  
  
  RESULTS
  Injury risk increased linearly with 1-wk loads and week-to-week changes in loads, with a 2-SD increase in these variables (1245 AU and 1069 AU, respectively) associated with odds ratios of 1.68 (95% CI 1.05-2.68) and 1.58 (95% CI 0.98-2.54). When compared with the reference group (<3684 AU), a significant nonlinear effect was evident for 4-wk cumulative loads, with a likely beneficial reduction in injury risk associated with intermediate loads of 5932-8651 AU (OR 0.55, 95% CI 0.22-1.38) (this range equates to around 4 wk of average in-season TL) and a likely harmful effect evident for higher loads of >8651 AU (OR 1.39, 95% CI 0.98-1.98).
  
  
  CONCLUSIONS
  Players had an increased risk of injury if they had high 1-wk cumulative loads (1245 AU) or large week-to-week changes in TL (1069 AU). In addition, a U-shaped relationship was observed for 4-wk cumulative loads, with an apparent increase in risk associated with higher loads (>8651 AU). These measures should therefore be monitored to inform injury-risk-reduction strategies.
authors: Dept for Health, University of Bath, Bath, UK.
authors: Matthew J
authors: MJ
authors: Cross
authors: Sean
authors: S
authors: Williams
authors: Grant
authors: G
authors: Trewartha
authors: Simon P
authors: SP
authors: Kemp
authors: Keith A
authors: KA
authors: Stokes
mesh_terms: D056352:Athletes; D001265:Athletic Injuries / Q000517:prevention & control*; D005538:Football / Q000293:injuries*; D006801:Humans; D008962:Models, Theoretical; D064797:Physical Conditioning, Human / Q000379:methods*; D011446:Prospective Studies; D012307:Risk Factors; D006113:United Kingdom