title: Effect of Repeated Whole Blood Donations on Aerobic Capacity and Hemoglobin Mass in Moderately Trained Male Subjects: A Randomized Controlled Trial.
abstract: BACKGROUND
  The aims of the present study were to investigate the impact of three whole blood donations on endurance capacity and hematological parameters and to determine the duration to fully recover initial endurance capacity and hematological parameters after each donation.
  
  
  METHODS
  Twenty-four moderately trained subjects were randomly divided in a donation (n = 16) and a placebo (n = 8) group. Each of the three donations was interspersed by 3 months, and the recovery of endurance capacity and hematological parameters was monitored up to 1 month after donation.
  
  
  RESULTS
  Maximal power output, peak oxygen consumption, and hemoglobin mass decreased (p < 0.001) up to 4 weeks after a single blood donation with a maximal decrease of 4, 10, and 7%, respectively. Hematocrit, hemoglobin concentration, ferritin, and red blood cell count (RBC), all key hematological parameters for oxygen transport, were lowered by a single donation (p < 0.001) and cumulatively further affected by the repetition of the donations (p < 0.001). The maximal decrease after a blood donation was 11% for hematocrit, 10% for hemoglobin concentration, 50% for ferritin, and 12% for RBC (p < 0.001). Maximal power output cumulatively increased in the placebo group as the maximal exercise tests were repeated (p < 0.001), which indicates positive training adaptations. This increase in maximal power output over the whole duration of the study was not observed in the donation group.
  
  
  CONCLUSIONS
  Maximal, but not submaximal, endurance capacity was altered after blood donation in moderately trained people and the expected increase in capacity after multiple maximal exercise tests was not present when repeating whole blood donations.
authors.affiliation: Exercise Physiology Research Group, Department of Kinesiology, KU Leuven, Leuven, Belgium.|Belgian Red Cross-Flanders, Mechelen, Belgium.
authors.forename: Julie
authors.initials: J
authors.lastname: Meurrens
authors.affiliation: Section for Elite Sport, Swiss Federal Institute of Sports, Magglingen, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Steiner
authors.affiliation: Exercise Physiology Research Group, Department of Kinesiology, KU Leuven, Leuven, Belgium.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Ponette
authors.affiliation: Exercise Physiology Research Group, Department of Kinesiology, KU Leuven, Leuven, Belgium.
authors.forename: Hans Antonius
authors.initials: HA
authors.lastname: Janssen
authors.affiliation: Exercise Physiology Research Group, Department of Kinesiology, KU Leuven, Leuven, Belgium.
authors.forename: Monique
authors.initials: M
authors.lastname: Ramaekers
authors.affiliation: Section for Elite Sport, Swiss Federal Institute of Sports, Magglingen, Switzerland.
authors.forename: Jon Peter
authors.initials: JP
authors.lastname: Wehrlin
authors.affiliation: Belgian Red Cross-Flanders, Mechelen, Belgium.|Faculty of Medicine, University of Ghent, Ghent, Belgium.|Department of Public Health and Primary Care, Faculty of Medicine, KU Leuven, Leuven, Belgium.
authors.forename: Philippe
authors.initials: P
authors.lastname: Vandekerckhove
authors.affiliation: Exercise Physiology Research Group, Department of Kinesiology, KU Leuven, Leuven, Belgium. louise.deldicque@uclouvain.be.|Institute of Neuroscience, Université catholique de Louvain, 1, Place Pierre de Coubertin box L08.10.01, 1348, Louvain-la-Neuve, Belgium. louise.deldicque@uclouvain.be.
authors.forename: Louise
authors.identifier: http://orcid.org/0000-0003-3393-5278
authors.initials: L
authors.lastname: Deldicque
keywords: Erythropoietin; Ferritin; Iron; Lactate; Maximal oxygen consumption; Maximal power output