title: External mechanical work versus oxidative energy consumption ratio during a basketball field test.
abstract: BACKGROUND
  A field test consisting of 5 continuous runs at the maximum speed possible, playing the ball, starting from the centre line to the basket with a final shot, was studied in order to obtain an index of mechanical work efficiency in basketball players (micro-index=Jmec/Joxy) and evaluate the correlation between micro-index and velocity, acceleration, mechanical power and lactacid anaerobic capacity, respectively.
  
  
  METHODS
  Eight male basketball players were studied; Jmec was the external mechanical work output obtained by means of a video image analysis software which gave the potential and the kinetic translational energies of athletes running and jumping and their velocity, acceleration and mechanical power. By means of a telemetric device (Kosmed K4), for measuring O2 consumption ( VO2), we obtained oxidative work (Joxy). By using this device we also assessed the excess of CO2, which was considered an index of lactacid anaerobic capacity.
  
  
  RESULTS
  Non-parametric Spearman statistics revealed a significant correlation between mu index and mean velocity (p<0.01, r=0.90), acceleration (p<0.05, r=0.78), mechanical power (p<0.05 r=0.76) and CO2 excess (p<0.01, r=0.95). Consequently athletes who had the best index of mechanical efficiency also had the best biomechanical quality and the greatest lactacid anaerobic capacity.
  
  
  CONCLUSIONS
  This study strongly supports the hypothesis that in basketball anaerobic capacity is important in achieving high values of speed, acceleration, mechanical power and endurance velocity.
authors.affiliation: Interdepartmental Center for the Technologies and the Environments Linked to Sport (CITAS), University of Cagliari, Cagliari, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Crisafulli
authors.forename: F
authors.initials: F
authors.lastname: Melis
authors.forename: F
authors.initials: F
authors.lastname: Tocco
authors.forename: P
authors.initials: P
authors.lastname: Laconi
authors.forename: C
authors.initials: C
authors.lastname: Lai
authors.forename: A
authors.initials: A
authors.lastname: Concu
mesh_terms: D000054:Acceleration; D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology*; D001490:Basketball / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology; D006801:Humans; D007700:Kinetics; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology; D018709:Statistics, Nonparametric
chemical_list: D019344:Lactic Acid