Final answer:
Athletes might engage in blood doping by removing and later re-injecting red blood cells to enhance oxygen delivery to their muscles, increasing endurance. This practice increases VO2 max but is illegal and comes with health risks including cardiovascular issues and potential for infection. The structure of red blood cells, rich in hemoglobin, enables effective oxygen transport.
Step-by-step explanation:
Athletes may remove and later re-inject red blood cells into their bodies to practice a form of performance enhancement known as blood doping. This method involves increasing the number of red blood cells (RBCs) available to deliver oxygen to an athlete's muscles, thereby enhancing endurance and performance. The red blood cells can be collected from the recipient themselves, a process called autologous transfusion, or from a donor, known as homologous transfusion.
Once collected, RBCs are concentrated and potentially stored by freezing. They can then be thawed and reintroduced into the athlete's bloodstream, where they increase the oxygen-carrying capacity and boost the VO2 max, which is the maximum rate of oxygen consumption during intense exercise. However, this practice is illegal in sports and poses significant health risks, such as increased blood viscosity, which can lead to cardiovascular problems and the risk of transmission of blood-borne pathogens if using a donor's blood.
The structure of red blood cells allows them to deliver oxygen efficiently due to the presence of hemoglobin. Hemoglobin is a protein within red blood cells that can bind to oxygen; each cell can carry approximately one billion molecules of oxygen, enormously increasing the body's capacity to transport oxygen to tissues.