Individuals who participate in cardiovascular exercise on a regular basis are more sensitive to the changes in the number of red blood cells in the body. A change in RBC count will affect exercise performance and can increase the risk of developing other problems, such as fatigue or change in appetite.
RBCs
Blood contains millions of RBCs, which are vital to maintaining the cardiovascular system. Hemoglobin and the element iron found in RBCs help transport oxygen and carbon dioxide throughout the body. The body continues to make RBCs in the bone marrow. Typically, all RBCs in the body are replaced every four months. The Australian Institute of Sport reports in Sports Medicine Journal that cardiovascular exercise can decrease the life span of RBCs, but since young cells are more efficient in transporting oxygen throughout the body, the newer RBCs improve exercise performance.
Function during Cardiovascular Exercise
During exercise, the body depends on the ability to transport oxygen to the working muscles. The body responds to cardiovascular exercise by increasing heart rate pump more RBCs and oxygen through the body. The body also responds to exercise by increasing the concentration of RBCs per unit of blood increasing the amount of oxygen each carries. When there are not enough RBCs to transport the oxygen and iron to the working muscles, the body slows down and muscle fatigue sets in.
Normal RBC Values
The normal range of RBC count varies depending on age and is measured as the number of RBCs per millimeter of blood. Adult males have an average of 4.6 to 5.9 million cells; for adult females, the normal range is 4.2 to 5.4 million cells. The different concentrations of RBCs in males in females results in men having the ability to perform at generally higher cardiovascular intensities.
RBC Problems
Exercisers, especially those who participate in endurance cardiovascular exercise, are more prone to lower concentrations of RBCs and iron deficiency. Cardiovascular exercise increases iron requirements, and often, iron intake and absorption is lower in regular exercisers. Runners often suffer from low concentrations of RBCs because RBCs are destroyed from the constant impact and pounding. Individuals who exercise on a regular daily basis lose iron through destruction of RBCs, sweat, decreased absorption of iron and by taking anti-inflammatory drugs.
Cardiovascular Fitness
Cardiovascular exercise trains the cardiovascular system to be more efficient. The number of RBCs the body produces increases with consistent cardiovascular exercise.
