Intravascular hemolysis and mean red blood cell age in athletes.
OBJECTIVE
Since the observation that mechanical stress causes red blood cell (RBC) destruction, foot-strike hemolysis has been used to explain sports anemia and RBC rejuvenation in athletes. Recently gained knowledge questions the importance of mechanical RBC trauma on RBC hemolysis in athletes.


METHODS
Male athletes (N = 90) and untrained male controls (N = 58) were investigated for aerobic performance, hematological parameters, serum erythropoietin concentration (EPO), soluble transferrin receptor concentration (sTFR), and erythrocyte aspartate aminotransferase activity (eAST).


RESULTS
On hard floor running disciplines (HFR, N = 26, short- and long-distance runners, triathletes) showed a lower eAST (P < 0.001) and thus no younger RBC population than not on hard floor running athletes (NHFR, N = 64, cyclists, soccer players, others) or the untrained control group (N = 58). HFR had higher but still normal EPO (P < 0.01) and no higher sTFR.


CONCLUSIONS
Because intravascular hemolysis occurs in swimmers, cyclists, and runners, and mean RBC age is not reduced in runners, mechanisms other than foot-strike hemolysis have to be considered as well. Possible reasons are intramuscular destruction, osmotic stress, and membrane lipid peroxidation caused by free radicals released by activated leukocytes. Intravascular hemolysis can even be regarded as physiological means to provide heme and proteins for muscle growth.
Robinson
Yohan
Y
Charité-Campus Benjamin Franklin, Institute for Sports Medicine, Berlin, Germany. yohan.robinson@charite.de
Cristancho
Edgar
E
Böning
Dieter
D
D000293:Adolescent; D000328:Adult; D001642:Bicycling; D004905:Erythrocyte Aging / Q000502:physiology*; D004920:Erythropoiesis; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005858:Germany; D006461:Hemolysis; D006801:Humans; D008297:Male; D013177:Sports