title: Maximal oxygen uptake and erythropoietic responses after training at moderate altitude.
abstract: Six well-trained male cross-county skiers trained for 7 days at 2700 m above sea level, their accommodation being at 1695 m. Blood samples for haemoglobin concentration [Hb], erythropoietin concentration [EPO] and reticulocyte count were collected before, during and after altitude exposure. Packed cell volume (PCV), red blood cell count (RBC), transferrin-iron saturation, mean red cell volume (MCV), mean corpuscular haemoglobin concentration (MCHC), maximal oxygen uptake, maximal achieved ventilation and heart rate were determined pre- and postaltitude exposure. The [EPO] increased significantly from pre-altitude (mean 36 mU.ml-1, SD 5) to maximal altitude values (mean 47 mU.ml-1, SD 3). The [Hb] had increased significantly above pre-altitude values (mean 8.8 mmol.l-1, SD 0.5) on day 2 (mean 9.1 mmol.l-1, SD 0.4) and day 7 (mean 9.4 mmol.l-1, SD 0.4) at altitude and on day 4 postaltitutde (mean 9.2 mmol.l-1, SD 0.4). The reticulocyte counts had increased significantly above pre-altitude values (mean 6%, SD 3%) on day 3 at altitude (mean 12%, SD 8%) and day 4 postaltitude (mean 10%, SD 5%). The RBC counts had increased on the 4th postaltitude day. The transferrin-iron saturation had decreased below pre-altitude values (mean 23%, SD 4%) on day 4 postaltitude (mean 14%, SD 5%) and had increased on day 11 postaltitude (mean 22%, SD 7%). There were no significant changes in MCV, MCHC, PCV, maximal oxygen uptake and maximal achieved ventilation, and heart rate pre- to postaltitude. These observations demonstrated an erythropoietic response to the altitude training which was not sufficient to increase the postaltitude maximal oxygen uptake.
authors.affiliation: Department of Clinical Physiology and Nuclear Medicine, University Hospital of Fredriksberg, Denmark.
authors.forename: T
authors.initials: T
authors.lastname: Klausen
authors.forename: T
authors.initials: T
authors.lastname: Mohr
authors.forename: U
authors.initials: U
authors.lastname: Ghisler
authors.forename: O J
authors.initials: OJ
authors.lastname: Nielsen
mesh_terms: D000293:Adolescent; D000328:Adult; D000531:Altitude; D004906:Erythrocyte Count; D004920:Erythropoiesis; D004921:Erythropoietin / Q000097:blood; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D010806:Physical Education and Training; D012156:Reticulocytes; D014168:Transferrin / Q000378:metabolism
chemical_list: D006454:Hemoglobins; D014168:Transferrin; D004921:Erythropoietin