Red blood cells in sports: effects of exercise and training on oxygen supply by red blood cells

Abstract

During exercise the cardiovascular system has to warrant substrate supply to working muscle. The main function of red blood cells in exercise is the transport of O2 from the lungs to the tissues and the delivery of metabolically produced CO2 to the lungs for expiration. Hemoglobin also contributes to the blood's buffering capacity, and ATP and NO release from red blood cells contributes to vasodilation and improved blood flow to working muscle. These functions require adequate amounts of red blood cells in circulation. Trained athletes, particularly in endurance sports, have a decreased hematocrit, which is sometimes called “sports anemia.” This is not anemia in a clinical sense, because athletes have in fact an increased total mass of red blood cells and hemoglobin in circulation relative to sedentary individuals. The slight decrease in hematocrit by training is brought about by an increased plasma volume (PV). The mechanisms that increase total red blood cell mass by training are not understood fully. Despite stimulated erythropoiesis, exercise can decrease the red blood cell mass by intravascular hemolysis mainly of senescent red blood cells, which is caused by mechanical rupture when red blood cells pass through capillaries in contracting muscles, and by compression of red cells e.g., in foot soles during running or in hand palms in weightlifters. Together, these adjustments cause a decrease in the average age of the population of circulating red blood cells in trained athletes. These younger red cells are characterized by improved oxygen release and deformability, both of which also improve tissue oxygen supply during exercise.

Comparison of Selected Morphological, Rheological and Biochemical Parameters of Winter Swimmers' Blood at the End of One Winter Swimming Season and at the Beginning of Another

“…SS 1/2 , EI max and SS 1/2 to EI max ratio were reported as means ± standard deviations (SD). The methodology of analysis was previously described in detail (BASKURT & MEISELMAN 2004, 2013BASKURT et al 2009). Statistical significance was defined as P#0.05.…”

“…The degree and direction of changes in the blood morphology are determined by the characteristics of physical exercise (type, load, duration and number of repetitions) and the athlete's characteristics (age, sex, training experience) (KELLY 2005et al, KOCHANSKA-DZIUROWICZ 2007et al, ROMAIN 2011MAIRBÄURL 2013). Erythrocyte and leukocyte counts reflect the changes in plasma volume and immunological processes, respectively.…”

Impact of Aerobic Exercises on Iron Deficiency Anemia in Girls

“…As a reaction to several days of aerobic exercise, plasma volume increases and hemoglobin and packed cell volume decrease on a long term basis. Mairbaurl (2013) [21] reported that the diverging results in the studies on Hb and training are due to the different duration of exercise training. Schmidt and Prommer, (2008) [22] concluded that adjustments of Hb by training are slow, and that a pronounced increase may require several years of training.…”

Acute Hematological Responses to a Maximal Incremental Treadmill Test

“…Em virtude disto, há um aumento considerável no hematócrito, além de uma elevação na concentração de hemácias, hemoglobina e indicadores da resposta imune, ou seja, alteração da hemoconcentração resultante da redução plasmática (Mairbaurl, 2013;Tsampoukos, Stokes, & Nevill, 2014).…”