title: Measured and estimated energy cost of constant and shuttle running in soccer players.
abstract: OBJECTIVE
  Players in team sports like soccer often make acceleration and deceleration movements, which are more energetically demanding than running at constant speed. The first aim of the present study was to estimate this difference in associated energy cost. To this end, we compared the actual energy cost of shuttle running to that of running at constant speed. In addition, since measuring oxygen consumption is not feasible during soccer, the study's second aim was to determine the validity of an indirect approach to estimate energy cost provided by di Prampero et al. (2005) using time-motion data obtained from a tracking system as input.
  
  
  METHODS
  Fourteen male amateur soccer players performed aerobic constant and continuous shuttle running at six different speeds (range = 7.5-10.0 km·h⁻¹) on artificial turf. Measured energy cost was compared to the energy cost estimated with di Prampero's (2005) equation using data from a local position measurement (LPM) system as input.
  
  
  RESULTS
  As expected, measured energy cost was significantly higher (∼30%-50%) for shuttle running than for constant running (P < 0.001), and this difference increased with speed. For constant running, estimated energy cost was significantly higher (6%-11%) than measured energy cost, whereas for shuttle running, estimated energy cost was significantly lower (-13% to -16%) than measured energy cost.
  
  
  CONCLUSIONS
  Shuttle running raised the player's energy cost of running compared to constant running at the same average speed. Although actual energy cost of constant running was significantly overestimated by di Prampero's approach using LPM data as input, actual energy cost of shuttle running was significantly underestimated.
authors.affiliation: 1Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, THE NETHERLANDS; 2Academy of Physical Education, Amsterdam University of Applied Sciences, THE NETHERLANDS; 3School of Sport & Education, Brunel University, Uxbridge, Middlesex, UNITED KINGDOM.
authors.forename: Tom Gerardus Antonia
authors.initials: TG
authors.lastname: Stevens
authors.forename: Cornelis Johannes
authors.initials: CJ
authors.lastname: De Ruiter
authors.forename: David
authors.initials: D
authors.lastname: Van Maurik
authors.forename: Chris Joannes Wilhelmus
authors.initials: CJ
authors.lastname: Van Lierop
authors.forename: Geert Jozef Peter
authors.initials: GJ
authors.lastname: Savelsbergh
authors.forename: Peter Jan
authors.initials: PJ
authors.lastname: Beek
mesh_terms: D000054:Acceleration; D054874:Athletic Performance / Q000502:physiology; D003654:Deceleration; D004734:Energy Metabolism / Q000502:physiology*; D006801:Humans; D008297:Male; D012420:Running / Q000502:physiology*; D012916:Soccer / Q000502:physiology*; D055815:Young Adult