title: Morning based strength training improves afternoon physical performance in rugby union players.
abstract: OBJECTIVE
  To determine if a morning training session could alter afternoon physical performance. Moreover, as testosterone (T) and cortisol (C) concentrations are significant predictors of physical performance, and both show circadian declines across the day, we examined the effects of morning training on diurnal T and C responses.
  
  
  METHODS
  Eighteen semi-professional rugby union players completed this randomised and counter-balanced study.
  
  
  METHODS
  Following morning saliva collection (0900 h), players completed a control (rested), Sprint (5 × 40 m) or Weights (3 repetition-maximum [RM] bench press and squat) trial. In the afternoon (15:00 h) of each trial, a further saliva sample was collected before players completed a performance test (3 RM back squat and bench press, 40 m sprint, countermovement jump [CMJ]).
  
  
  RESULTS
  Salivary T concentrations declined from am to pm under Control and Sprint, but not under Weights. Delta T, from am to pm, was greater under Control (-10.9 ± 2.4 pg ml(-1)) compared to Sprints (-6.2 ± 7.1 pg ml(-1)) and Weights (-1.2 ± 5.5 pg ml(-1)) (p ≤ 0.001). Delta C, from am to pm, was greater under Control compared to both Sprint and Weights (p<0.05). Players elicited better CMJ peak power, 40-m time, 3 RM bench and squat performance under Weights compared with Control and Sprint (p<0.05). Faster 40-m times were seen under Sprint, when compared to Control (p<0.05).
  
  
  CONCLUSIONS
  Performing morning strength training is associated with improved physical performance in the afternoon. Additionally, the circadian decline in T concentrations appeared offset by morning training. However, it is unclear if T concentrations are, in part, causal of these improved responses or simply a reflective marker.
authors.affiliation: UK Sport, London, UK; Bangor University, Bangor, UK.
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Cook
authors.affiliation: Applied Sports Technology Exercise and Medicine Research Centre (A-STEM), Health and Sport Portfolio, College of Engineering, Swansea University, Swansea, UK.
authors.forename: Liam P
authors.initials: LP
authors.lastname: Kilduff
authors.affiliation: Hamlyn Centre, Imperial College, London, UK.
authors.forename: Blair T
authors.initials: BT
authors.lastname: Crewther
authors.affiliation: Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden.
authors.forename: Martyn
authors.initials: M
authors.lastname: Beaven
authors.affiliation: Department of Sport, Exercise and Rehabilitation, Faculty of Health and Life Science, Northumberland Building, Northumbria University, Newcastle upon Tyne, UK. Electronic address: d.j.west@northumbria.ac.uk.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: West
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D002940:Circadian Rhythm; D015444:Exercise / Q000502:physiology*; D005538:Football / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D055070:Resistance Training / Q000379:methods*; D012463:Saliva / Q000378:metabolism; D013739:Testosterone / Q000378:metabolism*; D055815:Young Adult
chemical_list: D013739:Testosterone; D006854:Hydrocortisone
keywords: Potentiation; Power; Steroid hormone; Strength; Testosterone