Final answer:
Increasing the number of red blood cells enhances the oxygen-carrying capacity of the blood, which is advantageous for oxygen delivery to tissues. However, too many RBCs can cause polycythemia, leading to high blood viscosity, which poses health risks.
Step-by-step explanation:
The primary advantage of increasing the number of red blood cells (RBCs) in the body is to enhance the oxygen-carrying capacity of the blood, enabling the delivery of more oxygen to tissues throughout the body. The iron-containing protein hemoglobin, which gives blood its red color, binds oxygen and is densely packed within RBCs. With about 250 million molecules of hemoglobin in each RBC, and each hemoglobin molecule having the capacity to bind four oxygen molecules, an increase in RBCs means a significant enhancement in the blood's capacity to transport oxygen.
However, while an increased number of RBCs can improve oxygen transport and thereby aid cellular respiration and overall endurance, it is also important to be aware of the possible health risks associated with an overproduction of RBCs, known as polycythemia. This condition can raise the viscosity of the blood, making it more challenging for the heart to pump and can lead to complications like high blood pressure and increased risk of clots.