title: Mathematical simulation of energy expenditure and recovery during sprint cross-country skiing.
abstract: OBJECTIVE
  A cross-country sprint competition relies on maximal effort durations of 3-4 minutes. Significant anaerobic energy contribution is expected. Anaerobic energy contribution has been estimated in different sports to date from the accumulated O2 deficit. However, the O2-deficit model can be questioned. We investigate anaerobic energy contribution by applying other methods than the O2 deficit.
  
  
  METHODS
  Theoretical model development.
  
  
  RESULTS
  For sprint cross-country competitions, the anaerobic energy contribution was 20%-25% independent of the employed mathematical model. Recovery times of a minimum 20 minutes were found to be required after sprint races to be sure that the performance in subsequent heats was not influenced.
  
  
  CONCLUSIONS
  The O2-deficit model gave anaerobic energy results in agreement with other models from the literature. Recovery times of a minimum 20 minutes were found to be required after sprint races to be sure that the performance in subsequent heats was not influenced.
authors: Protection and Societal Security Division, Norwegian Defence Research Establishment, Kjeller, Norway.
authors: John F
authors: JF
authors: Moxnes
authors: Department of Geosciences, University of Oslo, Oslo, Norway.
authors: Eldbjørg Dirdal
authors: ED
authors: Moxnes
keywords: aerobic; anaerobic; endurance sport; models; recovery