Changes in plasma volume and red cell formation after a marathon competition.
The purpose of this study was to investigate middle-term influences of a marathon race on plasma volume (PV) and red cell production. We performed the following measurements in the blood of 15 male athletes: haemoglobin ([Hb]), haematocrit (Hct), plasma protein concentration ([Prot]), plasma osmolality, sodium concentration ([Na+]), potassium concentration ([K+]), aldosterone concentration ([Aldo]), haptoglobin concentration ([Hpto]), and the reticulocyte count, as well as the calculation of relative changes in PV, 3 days before and on 3-consecutive days after a marathon race. By the 2nd day of recovery PV had increased by 16%. Plasma osmolality and [K+] remained constant, whereas [Na+] had decreased slightly 2 days after the competition and [Aldo] tended to be elevated 1 day after the competition. [Hpto] was low before and 1 day after the competition and increased on the following days. Reticulocyte count was unaffected 1 day after the race, but increased by 106% on the 2nd day and was still elevated after 3 days. The causes for higher post-marathon plasma volumes and reticulocyte counts could be in the complex variations in hormonal regulation, which have not yet been sufficiently investigated.
Abteilung für Sport und Arbeitsphysiologie, Medizinische Hochschule Hannover, Federal Republic of Germany.
W
W
Schmidt
N
N
Maassen
U
U
Tegtbur
K M
KM
Braumann
D000328:Adult; D000704:Analysis of Variance; D001772:Blood Cell Count; D004920:Erythropoiesis; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008297:Male; D010807:Physical Endurance; D010953:Plasma Volume; D012156:Reticulocytes / Q000166:cytology; D012420:Running
D006454:Hemoglobins