Foot-strike Haemolysis after a 60 km Ultramarathon
(Blood Transfus. 2012 10:377-383). Lippi G, Schena F, Salvagno Gl, Aloe R, Banfi G, Guidi GC
Prepared by Matthew Stewart, MD, University of Utah Emergency Medicine Resident, Salt Lake City, UT, USA
Regular aerobic physical exercise has been associated with sports anemia, referring to low blood hemoglobin reflecting an adaptation to physical training, and is due to multiple factors. The effective contribution of foot-strike hemolysis due to red blood cell (RBC) damage during long-distance running is currently unknown. The investigators assessed the degree of hemolysis after a 60-km trail ultramarathon by analyzing blood samples from 18 athletes at 3 time points: after an overnight fast, just before the event, and within 10 minutes after completing the run. The investigators found no significant change in postexercise hemoglobin, RBC count, and hematocrit. Although a certain degree of hemolysis was observed, the authors proposed that the amount of RBC injury is clinically negligible. Additionally, the positive correlation of creatine kinase, lactate dehydrogenase, and aspartate aminotransferase indicated more muscle injury than RBC damage.
Limitations of the study include immediate sampling after the event and using trained athletes who may have reached a stable erythropoietic response through conditioning. In conclusion, the authors propose that acute foot-strike RBC injury may no longer be a contributor to the anemia seen in long-distance runners.