title: Anaerobic work calculated in cycling time trials of different length.
abstract: Previous research showed that gross efficiency (GE) declines during exercise and therefore influences the expenditure of anaerobic and aerobic resources.
  
  
  OBJECTIVE
  To calculate the anaerobic work produced during cycling time trials of different length, with and without a GE correction.
  
  
  METHODS
  Anaerobic work was calculated in 18 trained competitive cyclists during 4 time trials (500, 1000, 2000, and 4000-m). Two additional time trials (1000 and 4000 m) that were stopped at 50% of the corresponding "full" time trial were performed to study the rate of the decline in GE.
  
  
  RESULTS
  Correcting for a declining GE during time-trial exercise resulted in a significant (P<.001) increase in anaerobically attributable work of 30%, with a 95% confidence interval of [25%, 36%]. A significant interaction effect between calculation method (constant GE, declining GE) and distance (500, 1000, 2000, 4000 m) was found (P<.001). Further analysis revealed that the constant-GE calculation method was different from the declining method for all distances and that anaerobic work calculated assuming a constant GE did not result in equal values for anaerobic work calculated over different time-trial distances (P<.001). However, correcting for a declining GE resulted in a constant value for anaerobically attributable work (P=.18).
  
  
  CONCLUSIONS
  Anaerobic work calculated during short time trials (<4000 m) with a correction for a declining GE is increased by 30% [25%, 36%] and may represent anaerobic energy contributions during high-intensity exercise better than calculating anaerobic work assuming a constant GE.
authors.affiliation: MOVE Research Inst Amsterdam, VU University, Amsterdam, The Netherlands.
authors.forename: Roy C
authors.initials: RC
authors.lastname: Mulder
authors.forename: Dionne A
authors.initials: DA
authors.lastname: Noordhof
authors.forename: Katherine R
authors.initials: KR
authors.lastname: Malterer
authors.forename: Carl
authors.initials: C
authors.lastname: Foster
authors.forename: Jos J
authors.initials: JJ
authors.lastname: de Koning
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology*; D001642:Bicycling / Q000502:physiology*; D004526:Efficiency / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D006339:Heart Rate; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D013997:Time Factors; D055815:Young Adult