title: Peak power output, the lactate threshold, and time trial performance in cyclists.
abstract: OBJECTIVE
  To determine the relationship between maximum workload (W(peak)), the workload at the onset of blood lactate accumulation (W(OBLA)), the lactate threshold (W(LTlog)) and the D(max) lactate threshold, and the average power output obtained during a 90-min (W(90-min)) and a 20-min (W(20-min)) time trial (TT) in a group of well-trained cyclists.
  
  
  METHODS
  Nine male cyclists (.VO(2max) 62.7 +/- 0.8 mL.kg(-1).min(-1)) who were competing regularly in triathlon or cycle TT were recruited for the study. Each cyclist performed four tests on an SRM isokinetic cycle ergometer over a 2-wk period. The tests comprised 1) a continuous incremental ramp test for determination of maximal oxygen uptake (.VO(2max) (L.min(-1) and mL.kg(-1).min(-1)); 2) a continuous incremental lactate test to measure W(peak), W(OBLA), W(LTlog), and the D(max) lactate threshold; and 3) a 20-min TT and 4) a 90-min TT, both to determine the average power output (in watts).
  
  
  RESULTS
  The average power output during the 90-min TT (W(90-min)) was significantly (P < 0.01) correlated with W(peak) (r = 0.91), W(LTlog) (r = 0.91), and the D(max) lactate threshold (r = 0.77, P < 0.05). In contrast, W(20-min) was significantly (P < 0.05) related to .VO(2max) (L.min(-1)) (r = 0.69) and W(LTlog) (r = 0.67). The D(max) lactate threshold was not significantly correlated to W(20-min) (r = 0.45). Furthermore, W(OBLA) was not correlated to W(90-min) (r = 0.54) or W(20-min) (r = 0.23). In addition, .VO(2max) (mL.kg(-1).min(-1)) was not significantly related to W(90-min) (r = 0.11) or W(20-min) (r = 0.47).
  
  
  CONCLUSIONS
  The results of this study demonstrate that in subelite cyclists the relationship between maximum power output and the power output at the lactate threshold, obtained during an incremental exercise test, may change depending on the length of the TT that is completed.
authors.affiliation: Department of Sport and Exercise Science, University of Bath, Bath BA2 7AY, UK. sppdjb@bath.ac.uk
authors.forename: D J
authors.initials: DJ
authors.lastname: Bentley
authors.forename: L R
authors.initials: LR
authors.lastname: McNaughton
authors.forename: D
authors.initials: D
authors.lastname: Thompson
authors.forename: V E
authors.initials: VE
authors.lastname: Vleck
authors.forename: A M
authors.initials: AM
authors.lastname: Batterham
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold; D001642:Bicycling / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D010807:Physical Endurance / Q000502:physiology; D013647:Task Performance and Analysis; D013997:Time Factors
chemical_list: D019344:Lactic Acid