title: Stability of hemoglobin mass during a 6-day UCI ProTour cycling race.
abstract: OBJECTIVE
  Blood doping in endurance sport is a growing problem. The purpose of this study was to determine the reliability of total hemoglobin mass (Hb(mass)) measurement in the field and to establish the variability of Hb(mass) during a cycling race, to assess its viability as an additional antidoping detection parameter.
  
  
  METHODS
  Control-matched longitudinal study.
  
  
  METHODS
  International Cycling Union's (UCI) ProTour stage race.
  
  
  METHODS
  Six professional cyclists and 5 recreationally active controls.
  
  
  METHODS
  Seventy-two Hb(mass) tests using the optimized carbon monoxide rebreathing method were performed over 7 consecutive days, before and throughout the tour. Fasted venous blood was obtained for measurement of hematocrit (Hct) and hemoglobin concentration [Hb] in the morning before stages 1, 3, and 6 (D1, D3, and D6).
  
  
  METHODS
  Reliability of Hb(mass) measurement was established using typical error calculated from 2 baseline measures. Individual change scores and coefficients of variation were used to assess stability during racing.
  
  
  RESULTS
  Typical error for Hb(mass) was 1.3% [95% confidence limits (CL): 0.9%, 2.5%]. Calculated 95% and 99.99% CL for percent change in Hb(mass) were +/-3.6% and +/-7.2%, respectively. Mean Hb(mass) remained within +/-1.9% of baseline in cyclists and +/-0.5% in controls. In all cases, individual change scores for both cyclists and controls fell within the 95% CL. There was a decrease in Hct (8.1% +/- 2.8%) and [Hb] (9.7% +/- 3.2%) throughout the tour in cyclists but not in controls.
  
  
  CONCLUSIONS
  We demonstrate that Hb(mass) can be measured reliably via CO-rebreathing during a cycling tour. Unlike [Hb] and Hct, Hb(mass) remains stable over 6 days of racing in professional cyclists and may have potential in an antidoping context.
authors.affiliation: Department of Physiology, Australian Institute of Sport, Canberra, Australia. laura.garvican@ausport.gov.au
authors.forename: Laura A
authors.initials: LA
authors.lastname: Garvican
authors.forename: Annette
authors.initials: A
authors.lastname: Eastwood
authors.forename: David T
authors.initials: DT
authors.lastname: Martin
authors.forename: Megan L R
authors.initials: ML
authors.lastname: Ross
authors.forename: Anne
authors.initials: A
authors.lastname: Gripper
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Gore
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology*; D002248:Carbon Monoxide / Q000032:analysis; D004300:Doping in Sports / Q000517:prevention & control; D006454:Hemoglobins / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D005082:Physical Exertion / Q000502:physiology*; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D006454:Hemoglobins; D002248:Carbon Monoxide