In the aftermath of such a horrific, cowardly act on the city of New York and our Nation as a whole, the insidious perpetrators aimed to have our society bow down and cower in fear of their actions. Although in stunned silence and shock, our society has not bowed down to the terror but has chosen instead to actively help our fellow countrymen by donating our blood to local Red Cross Centers nationwide. The community of people that defines our nation has rallied to aid our fellow citizens in need. We at ISSA encourage our members to be regular contributors to blood banks nationwide, and feel compelled to educate our members on the need for their participation. As facilitators of education, we have received numerous questions on the effects of blood donation and the ability to return to physical activity. We will discuss the role of blood, its makeup and how donation effects performance.
During exercise, oxygen demand in the active muscles increases. This leads to more nutrients being used, speeding up metabolic processes and creating more waste. In intense exercise H+ concentration increases in the muscles and blood, lowering their pH. Numerous cardiovascular changes occur during exercise to allow the system to meet the increased demands placed upon it to carry out its functions with maximal efficiency. The components of the cardiovascular system are heart rate, stroke volume, cardiac output, blood flow, blood pressure, and the blood itself.
Since blood is the fluid that carries the needed substances to the tissues and clears away harmful substances, as metabolism increases, the function of blood becomes more vital for efficient performance. Blood serves many useful purposes in the regulation of normal body function. The three functions important to exercise are transportation, temperature regulation, and acid-base balance. In addition to its transportation functions, blood is critical in temperature regulation during physical activity. Blood helps regulate temperature control by taking heat from areas of increased metabolic activity and dissipating that heat and to the skin when the body is overheated and throughout the body during normal conditions. It can also buffer the acids produced by anaerobic metabolism, maintaining the proper pH for efficient activity of metabolic processes.
The total volume of blood in the body is dependent on individuals' size and state of training. Generally, the average blood volume range is from 5 to 6 liters in men and 4 to 5 liters in women. The composition of whole blood is 55% plasma (of which 90% is water, 7% plasma proteins and 3% other) and 45% formed elements (of which > 99% is red blood cells, and <1% white blood cells and platelets). Mature red blood cells (erythrocytes) have no nucleus, therefore they can not reproduce and must be replaced with new cells every 4 months. This balance is very important because adequate oxygen delivery to body tissues depend on having a sufficient number of carriers: red blood cells. Decreases in their count or function can hinder oxygen delivery and thus affect performance.
When donating blood; as thousands of Americans did in response to the attack on our Nation, the removal of one unit (nearly 500 ml) represents approximately an 8% to 10% reduction in both total blood volume and in the number of circulating red blood cells. Since blood is 55% plasma of which 90% is water, donors are advised to drink plenty of fluids to help replace plasma volume to normal within 24 to 48 hours. However, since red blood cells are formed elements, it takes at least six weeks to reconstitute the red blood cells. Resistance training which predominantly relies on the ATP/PCr or glycoyltic systems to produce ATP are both anaerobic systems and thus would not be detrimentally effected. However, blood loss greatly compromises the performance of endurance athletes by reducing the number of available red blood cells and thus reducing the oxygen-delivery capacity.
Blood serves many useful purposes in the regulation of normal body functions. From transportation, to temperature regulation and acid-base balance, the importance of blood can not be overstated. We at ISSA encourage all our students to consider their role in helping others through blood donation.
For more information on what you can do to help, please go to www.redcross.org .
For additional information on what you can do, please go to www.salvationarmy.org .
If you have questions or comments regarding this article, please feel free to contact patrick@issaonline.com .
