title: Physical and physiological demands of U-19 basketball refereeing: Aerobic and anaerobic demands.
abstract: OBJECTIVE
  This study aimed to examine the physical and physiological demands of basketball refereeing.
  
  
  METHODS
  16 elite-level basketball referees were studied during U-19 basketball games (n=8) for time-motion analyses, exercise heart rates (HR) and blood lactate concentration [La]. Game activities were considered as time spent and distance covered in five locomotors activities (standing, walking, jogging, running and sprinting).
  
  
  RESULTS
  Referees spent more time (p<0.01) walking (63.72±2.02 min) than jogging (3.10±0.29 min), running (4.24±0.46 min) and sprinting (1.69±0.24 min). Referees covered more distance (p<0.01) walking than jogging, running and sprinting across the quarters (Q). Mean HR (74.89±6.86 %HRmax) was not significantly different across the game Q (Q1 to Q4) and halves. [La] did not show significant changes (p=0.221) when comparing the half-time (4.30±3.92 mmol.L(-1)) and the end of the game (6.70±4.90 mmol.L(-1)).
  
  
  CONCLUSIONS
  In light of this study, we conclude that U-19 basketball refereeing is a moderate intensity activity where referees spent 81% of total game time at low-intensity with bouts of high-intensity activities throughout the game.
authors.affiliation: a Tunisian Research Laboratory "Sports Performance Optimization" , National Center of Medicine and Science in Sports (CNMSS) , Tunis , Tunisia.|b Department of biology, Faculty of Sciences of Bizerte , University of Carthage , Bizerte , Tunisia.
authors.forename: Mohamed Ali
authors.initials: MA
authors.lastname: Nabli
authors.affiliation: a Tunisian Research Laboratory "Sports Performance Optimization" , National Center of Medicine and Science in Sports (CNMSS) , Tunis , Tunisia.
authors.forename: Nidhal
authors.initials: N
authors.lastname: Ben Abdelkrim
authors.affiliation: c School of Sport and Exercise Sciences, Faculty of Medicine and Surgery , University of Rome Tor Vergata , Rome , Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Castagna
authors.affiliation: d Higher School of Sciences and Techniques of Tunis , University of Tunis , Tunis , Tunisia.
authors.forename: Imed
authors.initials: I
authors.lastname: Jabri
authors.affiliation: d Higher School of Sciences and Techniques of Tunis , University of Tunis , Tunis , Tunisia.
authors.forename: Tahar
authors.initials: T
authors.lastname: Batikh
authors.affiliation: e Athlete Health and Performance Research Centre , ASPETAR, Qatar Orthopedic and Sports Medicine Hospital , Doha , Qatar.
authors.forename: Karim
authors.initials: K
authors.lastname: Chamari
mesh_terms: D000328:Adult; D001490:Basketball / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007590:Jogging / Q000502:physiology; D019344:Lactic Acid / Q000097:blood; D008297:Male; D012420:Running / Q000502:physiology; D013996:Time and Motion Studies; D016138:Walking / Q000502:physiology
chemical_list: D019344:Lactic Acid
keywords: Movement; category; competition; intermittent; metabolism