Objective: Blood doping in endurance sport is a growing problem. The purpose of this study was to determine the reliability of total hemoglobin mass (Hbmass) measurement in the field and to establish the variability of Hbmass during a cycling race, to assess its viability as an additional antidoping detection parameter.
Design: Control-matched longitudinal study.
Setting: International Cycling Union's (UCI) ProTour stage race.
Participants: Six professional cyclists and 5 recreationally active controls.
Interventions: Seventy-two Hbmass 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).
Main Outcome Measures: Reliability of Hbmass 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 Hbmass was 1.3% [95% confidence limits (CL): 0.9%, 2.5%]. Calculated 95% and 99.99% CL for percent change in Hbmass were ±3.6% and ±7.2%, respectively. Mean Hbmass 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 Hbmass can be measured reliably via CO-rebreathing during a cycling tour. Unlike [Hb] and Hct, Hbmass remains stable over 6 days of racing in professional cyclists and may have potential in an antidoping context.
From the *Department of Physiology, Australian Institute of Sport, Canberra, Australia; †Exercise Physiology Laboratory, Flinders University, Adelaide, Australia; ‡South Australian Sports Institute, Adelaide, Australia; and §Union Cycliste Internationale, Aigle, Switzerland.
Submitted for publication October 11, 2009; accepted March 15, 2010.
Funding for this study was received from Cycling Australia and Flinders University.
The results of this study do not constitute endorsement from the International Cycling Union.
The authors state that they have no financial interest.
Reprints: Laura A. Garvican, Bsc (Hons), Australian Institute of Sport, PO Box 176, Belconnen, ACT 2616, Australia (e-mail: firstname.lastname@example.org).