title: A standard blood bank donation alters the thermal and cardiovascular responses during subsequent exercise.
abstract: BACKGROUND
  The fear for adverse effects of blood donation on subsequent exercise may prevent physically active people from donating. We studied the impact of a standard blood bank donation (i.e., 450-mL blood withdrawal) on the thermoregulatory and cardiovascular responses to prolonged exercise in the heat.
  
  
  METHODS
  Eight moderately trained, heat-acclimated males cycled for 1 hour at 60% in a hot environment (34.9±0.6 °C) on four occasions: 1) 2 days before blood donation (CON), 2) 2 hours after donation (DON), 3) 2 days after donation (2 DAYS), and 4) 7 days after donation (7 DAYS).
  
  
  RESULTS
  Two-thirds of the blood volume withdrawn was endogenously restored before exercise in the DON trial (p<0.05). DON started with increased preexercise rectal temperature (TRE; 0.42±0.1 °C above CON; p<0.05), which resulted in high levels of hyperthermia (i.e., 39.0±0.2 °C) after 1 hour of exercise. Skin temperature (34.5±0.1 °C) and sweat rate (1.15±0.1 L/h) were not affected by DON. However, DON lowered the skin blood flow:TRE relationship and elevated heart rate (HR) above CON (12±4 beats/min; p<0.05) maintaining cardiac output. After 2 DAYS, TRE and HR were restored to CON levels while cardiac output increased above CON (6%; p<0.05) in association with reduced hemoglobin concentration (i.e., peak hemodilution).
  
  
  CONCLUSIONS
  A blood bank donation increases preexercise TRE. Subsequent exercise in a hot environment results in high levels of hyperthermia and HR. These thermoregulatory and cardiovascular perturbations observed during exercise disappear 2 days after donation.
authors.affiliation: Exercise Physiology Laboratory at Toledo, University of Castilla-La Mancha, Toledo, Spain. Ricardo.Mora@uclm.es
authors.forename: Ricardo
authors.initials: R
authors.lastname: Mora-Rodriguez
authors.forename: Roberto
authors.initials: R
authors.lastname: Aguado-Jimenez
authors.forename: Juan
authors.initials: J
authors.lastname: Del Coso
authors.forename: Emma
authors.initials: E
authors.lastname: Estevez
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D000328:Adult; D001782:Blood Donors; D001794:Blood Pressure / Q000502:physiology; D001831:Body Temperature / Q000502:physiology; D001833:Body Temperature Regulation / Q000502:physiology*; D050260:Carbohydrate Metabolism / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005334:Fever / Q000097:blood / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D012881:Skin Temperature / Q000502:physiology; D013546:Sweating / Q000502:physiology; D055815:Young Adult
chemical_list: D006454:Hemoglobins; D019344:Lactic Acid