Introduction: Marked changes in different blood variables, e.g. hemoglobin concentration ([Hb]) and hematocrit (Hct), are indications of blood manipulation. Blood sampling and the development of individual, longitudinal blood profiles have therefore been implemented in doping control in different sports federations.
Materials and methods: During the Tour de France 2007, 7 riders were randomly tested on 3 different occasions; the day before the prologue, and 12 and 19 days after the prologue. Blood was drawn into 3 mL EDTA covered tubes and kept at 4 degrees Celsius. They were analyzed within 24 hours on a Sysmex R-500.
Results: [Hb] and Hct were significantly lower on day 12 (p = 0.005) and day 19 (p < 0.001) compared to baseline. All 7 riders had lower [Hb] and Hct on day 19 compared to baseline, while this was the case in 6 out of 7 riders already on day 12. The [Hb] and Hct were 11.5% and 12.1% lower on day 19 compared to baseline.
Conclusion: We observed significant decreases in [Hb] and Hct in 7 riders during Tour de France 2007. Whether or not this is due to decrease in hemoglobin mass or hemodilution, or the latter solely, increases in [Hb] and Hct during prolonged stage racing seem unphysiological and should therefore lead to further examination of the rider.