title: Power output during stage racing in professional road cycling.
abstract: OBJECTIVE
  The aim of the study was to evaluate the power output during a multistage professional road race using direct power measurements and to compare these results with the performance measurements using competition heart rate recordings.
  
  
  METHODS
  Six professional road cyclists performed an incremental cycling test during which peak power output, power output, and heart rate at the lactate threshold (LT) and at a lactate increase of 1 mM above the LT (LT + 1) were assessed. During a six-stage road race competition, power output was measured directly (SRM crankset). To analyze the time spent at different intensities during competition, the amount of competition time spent below LT (zone 1), between the LT and LT + 1 (zone 2), and above LT + 1 (zone 3) determined during laboratory testing were calculated for power output and heart rate.
  
  
  RESULTS
  During the five mass start stages, a mean power output of 220 +/- 22 W (3.1 +/- 0.2 W x kg(-1)) with a mean heart rate of 142 +/- 5 bpm was measured. Average power output during an uphill time trial was 392 +/- 60 W (5.5 +/- 0.4 W x kg(-1)) with a mean heart rate of 169 +/- 3 bpm. For the mass start stages, the average distribution of exercise time spent in different intensities calculated for power output and heart rate was 58 versus 38% for zone 1, 14 versus 38% for zone 2, and 28 versus 24% for zone 3.
  
  
  CONCLUSIONS
  Most of the competition time during the mass start stages was spent at intensities near the LT. Compared with power output, heart rate measurement underestimated the time spent at intensity zones 1 and 3, and overestimated the time spent in zone 2.
authors.affiliation: University of Freiburg, Center for Internal Medicine, Department of Prevention, Rehabilitation and Sports Medicine, Freiburg, Germany. stefan.vogt@uniklinik-freiburg.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Vogt
authors.forename: Lothar
authors.initials: L
authors.lastname: Heinrich
authors.forename: Yorck Olaf
authors.initials: YO
authors.lastname: Schumacher
authors.forename: Andreas
authors.initials: A
authors.lastname: Blum
authors.forename: Kai
authors.initials: K
authors.lastname: Roecker
authors.forename: Hans-Hermann
authors.initials: HH
authors.lastname: Dickhuth
authors.forename: Andreas
authors.initials: A
authors.lastname: Schmid
mesh_terms: D000328:Adult; D001642:Bicycling; D005858:Germany; D006339:Heart Rate; D006801:Humans; D008297:Male; D005082:Physical Exertion / Q000502:physiology*; D013177:Sports; D013647:Task Performance and Analysis