title: Sport-Specific Physiological Adaptations in Highly Trained Endurance Athletes.
abstract: OBJECTIVE
  This study aims to compare maximal oxygen uptake (V˙O2max), blood volume (BV), hemoglobin mass (Hbmass), and brachial endothelial function, measured as flow-mediated dilatation (FMD), in international-level endurance athletes primarily exercising with the whole body (cross-country skiing), lower body (orienteering), or upper body (flatwater kayak).
  
  
  METHODS
  Seventeen cross-country skiers, 15 orienteers, and 11 flatwater kayakers were tested for V˙O2max, BV, Hbmass, and FMD. Additionally, body composition and annual training (type, volume, and intensity of training) were analyzed.
  
  
  RESULTS
  Absolute and body-mass-normalized V˙O2max values were 11.3% and 9.9% higher, respectively, in skiers (5.83 ± 0.60 L·min and 77.9 ± 4.2 mL·min·kg) compared to orienteers (5.24 ± 0.45 L·min and 70.9 ± 3.5 mL·min·kg) (P < 0.01), whereas kayakers (5.78 ± 0.56 L·min and 73.7 ± 6.3 mL·min·kg) did not differ from skiers. BV was 9.9%-11.8% higher in skiers and orienteers compared to kayakers when normalized for total body mass and fat-free mass, and skiers had 9.2% and 9.9% higher Hbmass normalized for total body mass and fat-free mass compared to kayakers (all P < 0.05). Arterial diameter was 11.8%-15.0% larger in kayakers (4.38 ± 0.63 mm) and skiers (4.22 ± 0.36 mm) compared to orienteers (3.81 ± 0.32 mm) (P < 0.05), whereas FMD did not differ between groups.
  
  
  CONCLUSIONS
  This study indicates that higher V˙O2max in cross-country skiers and greater arterial diameters in the arms of skiers and kayakers are sport-specific physiological adaptations to chronic endurance training in whole-body and upper-body exercise modes. However, variations in these variables are not associated with BV or Hbmass.
authors: 1K.G. Jebsen Center for Exercise in Medicine, Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, NORWAY; 2Department of Cardiology, St. Olavs University Hospital, Trondheim, NORWAY; 3Center for Elite Sports Research, Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, NORWAY; and 4Wales Heart Research Institute, Department of Cardiology, Cardiff University, Cardiff, UNITED KINGDOM.
authors: Kari Margrethe
authors: KM
authors: Lundgren
authors: Trine
authors: T
authors: Karlsen
authors: Øyvind
authors: Ø
authors: Sandbakk
authors: Philip E
authors: PE
authors: James
authors: Arnt Erik
authors: AE
authors: Tjønna
mesh_terms: D000222:Adaptation, Physiological; D001810:Blood Volume; D015992:Body Mass Index; D001916:Brachial Artery / Q000502:physiology; D003430:Cross-Sectional Studies; D004730:Endothelium, Vascular / Q000502:physiology; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D035002:Lower Extremity / Q000502:physiology; D008297:Male; D009051:Mountaineering / Q000502:physiology; D010101:Oxygen Consumption; D010806:Physical Education and Training; D010807:Physical Endurance / Q000502:physiology*; D012767:Ships; D012865:Skiing / Q000502:physiology; D013177:Sports / Q000502:physiology; D034941:Upper Extremity / Q000502:physiology; D014664:Vasodilation; D055815:Young Adult
chemical_list: D006454:Hemoglobins