title: Altitude training causes haematological fluctuations with relevance for the Athlete Biological Passport.
abstract: The impact of altitude training on haematological parameters and the Athlete Biological Passport (ABP) was evaluated in international-level elite athletes. One group of swimmers lived high and trained high (LHTH, n = 10) for three to four weeks at 2130 m or higher whereas a control group (n = 10) completed a three-week training camp at sea-level. Haematological parameters were determined weekly three times before and four times after the training camps. ABP thresholds for haemoglobin concentration ([Hb]), reticulocyte percentage (RET%), OFF score and the abnormal blood profile score (ABPS) were calculated using the Bayesian model. After altitude training, six swimmers exceeded the 99% ABP thresholds: two swimmers exceeded the OFF score thresholds at day +7; one swimmer exceeded the OFF score threshold at day +28; one swimmer exceeded the threshold for RET% at day +14; and one swimmer surpassed the ABPS threshold at day +14. In the control group, no values exceeded the individual ABP reference range. In conclusion, LHTH induces haematological changes in Olympic-level elite athletes which can exceed the individually generated references in the ABP. Training at altitude should be considered a confounding factor for ABP interpretation for up to four weeks after altitude exposure but does not consistently cause abnormal values in the ABP.
authors.affiliation: Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Denmark.
authors.forename: Thomas Christian
authors.initials: TC
authors.lastname: Bonne
authors.affiliation: Zurich Center of Integrative Human Physiology, Institute of Physiology, University of Zürich, Switzerland.
authors.forename: Carsten
authors.initials: C
authors.lastname: Lundby
authors.affiliation: Department of Cardiology, Copenhagen University Hospital at Hvidovre, Copenhagen, Denmark.
authors.forename: Anne Kristine
authors.initials: AK
authors.lastname: Lundby
authors.affiliation: Department of Cardiology, Copenhagen University Hospital at Hvidovre, Copenhagen, Denmark.
authors.forename: Mikael
authors.initials: M
authors.lastname: Sander
authors.affiliation: Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Denmark.
authors.forename: Jacob
authors.initials: J
authors.lastname: Bejder
authors.affiliation: Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Denmark.
authors.forename: Nikolai Baastrup
authors.initials: NB
authors.lastname: Nordsborg
mesh_terms: D000531:Altitude; D056352:Athletes; D054874:Athletic Performance; D001499:Bayes Theorem; D004300:Doping in Sports; D004921:Erythropoietin / Q000097:blood; D005260:Female; D006403:Hematologic Tests; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008297:Male; D012156:Reticulocytes / Q000166:cytology; D013550:Swimming
chemical_list: D006454:Hemoglobins; D004921:Erythropoietin
keywords: Athlete Biological Passport; altitude; haematology