Boost Your Blood Oxygen-Carrying Capacity With Iron-Rich Foods

Improve Your Stamina and Aerobic Fitness With Papaya

Improve Your Stamina With PapayaCredit: TenaciousR's PhotostreamCredit: TenaciousR's Photostream

The body needs oxygen and nutrients for stamina and physical fitness. The primary function of blood is to deliver oxygen and nutrients to the active muscles and various organs, and remove waste products from them. Blood also prevents the body from overheating by transferring excess heat from the active muscles to the outside. To effectively perform its basic functions and improve stamina and fitness, blood can undergo significant changes. The Haldane effect, the Bohr effect, and increase in the synthesis of the red blood cells (erythropoesis) are some of the changes that enable the blood to meet the body's metabolic demands and support physical fitness.

The Heart and Lungs

Physiological changes in the blood are important for supporting stamina and fitness. Blood, however, can not perform its function in the absence of the heart and lungs. Blood must be pumped to the lungs to pickup oxygen which is then delivered to the organs and tissues of the body. The functionality of blood is enhanced by improvements in the performances of the heart and lungs as has been discussed in the article “Aerobic Fitness: Primed by Endurance and Stamina”.

Hemoglobin and Oxygen-Carrying Capacity of the Red Blood Cells

Red blood cells are the primary components of blood that carry oxygen to various organs and tissues of the body. Only very small amount of oxygen ( about 2 per cent) is carried by the plasma. This small amount of oxygen can not support human life. Hemoglobin is the constituent of the red blood cell that binds to oxygen, and facilitates the delivery of significant amounts of oxygen to the body.

Iron is an important structural  component of the normal hemoglobin. Consequently, inclusion of iron in your diet can improve the oxygen-carrying capacity of the red blood cells and the availability of oxygen to support stamina and physical fitness.  Improved oxygen delivery to your body reduces fatigue and tiredness. It improves your stamina. Iron can be obtained from supplements or from foods. Iron-rich foods include beef, oysters, turkey, eggs, dried fruits and kale.

Haldane and Bohr Effects

Blood supports stamina and physical fitness because of it can change the avidity with which it binds to oxygen in the lungs, and the ease with which it releases this bound oxygen in the active muscles. The Haldane and Bohr effects describe how hemoglobin changes its binding affinity for oxygen and carbon dioxide. The Bohr effect describes how changes in the partial pressure of oxygen (oxygen concentration) affects the binding affinity of hemoglobin for carbon dioxide. Bohr effect shows an inverse relationship between the partial pressure of oxygen and the hemoglobin's binding affinity for carbon dioxide. According to the Bohr effect, hemoglobin will bind tightly to carbon dioxide when the partial pressure of oxygen is low.

Haldane effect describes how changes in the partial pressure of carbon dioxide affects the hemoglobin's binding affinity for oxygen. An inverse relationship is also shown here. Therefore, hemoglobin binds loosely to oxygen when the partial pressure of carbon dioxide is high as would be the case in the active muscles. The effectiveness of meeting the body's oxygen needs is reflected by how tightly oxygen binds to hemoglobin and how quickly the bound oxygen is released to the active muscles and other organs.

If one were to engage in intense physical activity, oxygen demand would go up. Metabolic waste products, carbon dioxide and hydrogen ion, would also go up. An environment of lowered level of oxygen and elevated level of carbon dioxide would result. In this environment of high partial pressure of carbon dioxide, hemoglobin would bind very weakly to oxygen (Haldane effect). Oxygen would then be readily delivered to the active muscles. The hemoglobin binding affinity for carbon dioxide would go up (Bohr effect). Carbon dioxide would then be picked up very quickly from the active muscle and carried to the lungs for expiration.

In the lungs, the partial pressure of carbon dioxide in the inhaled air is low whereas the partial pressure of oxygen is high, therefore, blood coming to the lungs would enter a region with low partial pressure of carbon dioxide. This would enhance the hemoglobin's binding affinity for oxygen according to the Bohr effect. It would lower the binding affinity of hemoglobin for carbon dioxide according to the Haldane effect. Consequently, carbon dioxide would be released from the blood while oxygen is avidly taken up.

These changes in  the activity of blood function helps the body to meet its oxygen demand. It also enables the body to maintain normal acid-base balance. The pH (e.g., plasma pH) is a measure of the acid-base balance of the blood. The plasma pH must be maintained in the normal range for the body to work properly. Increases in the blood carbon dioxide contributes to acidosis (lowering of plasma pH) because of the way carbon dioxide level affects the bicarbonate buffer system. Carbon dioxide reacts with the bicarbonate ions to shift the reaction equilibrium to the left, a change that increases acidity (lowers the pH).

The Haldane and Bohr effects are important physiological concepts that explain how oxygen and carbon dioxide are exchanged in the body, but they can be difficult to understand. Explanation of gas exchanges in terms of partial pressures of the gases and their respective pressure gradients is easier to grasp. Gases such as oxygen and carbon dioxide will diffuse in and out of the tissues relative to their pressure gradients. Therefore, oxygen will move from a region of high oxygen concentration (such as the lungs) to a region of lower oxygen concentration (the blood). A similar scenario is true for the diffusion of carbon dioxide from the tissues to the blood.

Production of the Red Blood Cells

The long-term response to increased oxygen demand is an increase in the number of t red blood cells. This occurs by an increase in the production of red blood cells by the bone marrow. The production of blood cells is called hemopoesis. I ncrease in the production of the red blood cells is specific referred to as erythropueisis. When the numbers of red cells go up the oxygen-carrying capacity of blood rises. Improvements in endurance, stamina and physical fitness is then be facilitated.

Erythropoesis can be stimulated by factors that increase your body's oxygen demand such as increase in physical activity or by a reduction in the ambient oxygen level. Aerobic and endurance exercises are particularly beneficial for improving hemopoesis. Exercise-induced hemopoesis is remarkably enhanced by aerobic exercises at high altitudes in conditions of lowered partial pressure of oxygen.