We know that blood is vital to life. It carries oxygen and nutrients to keep our organs in good working condition; it has an essential role in cellular repair and body defense; it performs many other life-sustaining functions. But most of us don't give as much thought to blood health as we do to the individual health of different body components, organs, and systems. So what is blood health, and how does it affect overall health? Why is good blood health significant for athletes and active people?

What Is Blood Health? 

When we talk about blood health, we refer to the blood's ability to perform many functions, such as transporting oxygen and nutrients and fighting infections. Optimal blood health and function depend on the optimal health and function of blood components. So let us look at blood's main components to understand the bigger picture of blood health better. 

Main Components of Blood:

• Plasma: Plasma is the liquid component of blood and is 92% water, 7% vital proteins and 1% mineral salts, sugars, fats, hormones and vitamins. Plasma makes up around 55% of blood and is responsible for maintaining blood pressure and blood volume, supplying proteins that are critical for immunity and blood clotting, transporting blood cells throughout the body, and maintaining proper pH balance in the body by carrying electrolytes and potassium to the muscles.
• Erythrocytes: These are the red blood cells (RBCs) that give blood its color. RBCs are mainly responsible for carrying oxygen from the lungs to the rest of the body and carbon dioxide back to the lungs to be exhaled. A drop of blood contains between 4 and 6.2 million RBCs. Around 2 million RBCs are produced by the body every second.
• Leukocytes: These are the white blood cells (WBCs) which are a vital part of the body’s defense against diseases and infections. WBCs make up less than 1% of blood; between 3,700 and 10,500 WBCs are present in a single blood drop. 
• Thrombocytes: Also known as platelets, these are cell fragments suspended in plasma. Their primary function is to prevent or stop bleeding by attaching to the lining of blood vessels and interacting with clotting proteins. A single drop of blood contains between 150,000 and 400,000 platelets. 
• Water. Because water is a critical component of blood, hydration is crucial to blood flow and blood health. When you are dehydrated, your blood volume decreases, leading to a drop in blood pressure. Low hydration also means organs and tissues will not receive as much oxygen and nutrients — critical to organ function.

The bone marrow produces red blood cells, white blood cells and platelets. From the bone marrow, they enter the bloodstream and are carried by plasma throughout the body through the blood vessels. On the other hand, plasma is derived from the water absorbed by the intestines from the food we eat. 

5 Essential Functions Blood

Blood is part of the circulatory system, also made up of the heart and the blood vessels (arteries, veins and capillaries). The heart pumps the blood, which travels through the blood vessels to carry oxygen from the lungs to the rest of the body and transport carbon dioxide to the lungs for exhalation. Blood also gathers nutrients from the small intestines and transports them to every cell. 

When you have optimal blood health, your blood effectively carries out the following functions:

1. Transportation – As your blood circulates, it transports oxygen and nutrients throughout the body. The body uses oxygen and nutrients to create energy. When healthy blood reaches your active muscles, you experience increased training volumes and delayed fatigue. Blood also transports toxins and waste, such as lactic acid, for removal from the body to promote faster recovery.
2. Circulation – Blood health and proper circulation go hand in hand. Because blood is the primary carrier of nutrients in the body, it’s also how harmful deposits of unhealthy substances are transported to the blood vessels and other organs. Circulation issues often lead to blood flow difficulties and are usually caused by problems in the blood vessels, such as plaque buildup or narrowing of the vessels. Problems with the blood itself, such as blood clots, can also lead to the inefficient delivery of oxygen and nutrients. When your blood is healthy, it transports nutrients throughout the body, ensuring organs function properly, wounds heal faster, and your brain works with more clarity. Healthy blood circulation impacts performance and is vital for maintaining optimal movement. High cholesterol levels, for example, are linked to an unhealthy diet, inactivity and obesity, among other factors. Cholesterol is a nonessential nutrient carried through the blood and used by the body to build healthy cells. However, too much cholesterol in the blood can accumulate on the arterial walls.
3. Regulation – Blood plays a role in maintaining balance by regulating the body’s systems. As blood circulates, it absorbs or dissipates heat. In doing so, it helps to regulate body temperature. For example, warm blood circulates from your body’s core, where it is warmed, and then to the surface of your skin, where heat radiates from your blood, out into the environment. That means increased body temperature can impair endurance and negatively impact athletic performance. The same goes for cold bodies. When the environment is too cold, blood doesn’t circulate to extremities so that it can maintain the body’s core heat. That means muscle activity and performance are severely limited unless you can create movement and move to a warmer environment.
4. Protection – Along with oxygen and nutrients, blood carries antibodies throughout the body. Antibodies fight infection and play a vital role in maintaining the body's immune system. When inflammation occurs, chemicals from your white blood cells enter your blood or tissues to protect your body. Increased blood flow reduces stiffness, relaxes the muscles, promotes flexibility and provides overall comfort to the painful area.
5. Regeneration – Blood can’t be manufactured. There are no substitutes for platelets or plasma. If your body stops producing enough new blood cells, you’ll be unable to keep yourself warm or cool off. You’ll significantly reduce the ability to fight infections. And the transportation of waste is reduced, often leading to toxic conditions if the inability to remove waste continues for too long.  The body must regenerate blood to keep your systems functioning properly.

Common Blood Disorders

Blood disorders are usually genetic, but they can also be caused by nutrient deficiencies, other diseases or certain medicines. These disorders are identified based on which blood components or functions are affected:

• Blood clotting or platelet disorders can cause excessive clotting or bleeding. 
• A low RBC count can result in anemia, characterized by inadequate oxygen in the blood.
• Cancers of the blood, such as leukemia and myeloma, affect blood cells and the bone marrow. 
• Eosinophilia is a disorder affecting eosinophils, a type of white blood cell. 

Blood disorders can be diagnosed with a simple complete blood count (CBC), which provides information about blood cell types, RBC count, WBC count, platelet count and protein content. A blood smear is another diagnostic test that can help a doctor identify a blood disorder depending on variations in the size and shape of blood cells. 

Eating Healthy and Staying Active To Maintain Blood Health

Focus on blood health is scarce. As a result, health concerns commonly arise only when the problem has gone beyond the blood and is already affecting other organs and systems. However, many health issues can be prevented when we readjust our focus and adopt a healthy diet and lifestyle that benefits blood health.

Nutrition for Red Blood Cells

As red blood cells are the most common cells in the blood and have the critical task of carrying oxygen, proper nutrition that supports RBCs' healthy production and function is just as important. Therefore, make sure your diet is rich in the following nutrients to help maintain a healthy RBC count:

Iron

Having an iron-rich diet is vital to the producing of hemoglobin, the molecule responsible for the red color of RBCs and for carrying oxygen. Low hemoglobin levels are the leading cause of anemia, which is characterized by shortness of breath, fatigue, weakness, pale skin and chest pain. When your diet is deficient in iron, there’s not enough oxygen circulating in the body. People with iron-deficiency anemia often need to take iron supplements. Eating these foods can also help increase iron intake:

• Beef and other red meats
• Organ meats like kidney and liver
• Beans
• Legumes
• Dark green leafy vegetables like kale and spinach
• Dried fruits like apricots, prunes and raisins
• Nuts
• Egg yolks
• Fortified cereals

Folic Acid

Folic acid, or folate, which is a B vitamin, also plays an essential role in the formation of red blood cells. More specifically, it is needed to form heme, the iron-containing portion of hemoglobin. Folate deficiency, therefore, can also lead to anemia. Foods rich in folic acid include:

• Dark green leafy vegetables (turnip greens, spinach, romaine lettuce, asparagus, Brussels sprouts, broccoli)
• Beans
• Peanuts
• Sunflower seeds
• Fresh fruits, fruit juices
• Whole grains
• Liver
• Seafood
• Eggs
• Fortified foods and supplements

Vitamin B12

Also known as cobalamin, this B vitamin is the largest and most structurally complicated vitamin and is also an essential component in healthy red blood cell production. These dietary sources of vitamin B12 can help maintain good blood health:

• Beef
• Pork
• Ham
• Poultry
• Lamb
• Fish, especially haddock and tuna
• Dairy products such as milk, cheese and yogurt
• Some nutritional yeast products
• Eggs
• Fortified milk and breakfast cereals

Copper

Blood needs sufficient amounts of copper to absorb iron from the gut properly. Good sources of copper include:

• Oysters and other shellfish
• Whole grains
• Beans
• Nuts
• Potatoes
• Organ meats (kidney, liver)
• Dark leafy greens
• Dried fruits
• Yeast

Nutrition for White Blood Cells

White blood cells are an essential component of our body’s immune system. If you want to fortify your body’s defenses, eating good quality protein (lean meats and poultry) and foods rich in vitamin C can help. Amino acids, the building blocks of protein and vitamin C, are vital to white blood cell production. A diet that supports WBC production is especially important when you’re sick or immuno-compromised. 

Staying Active To Promote Blood Health

Regular physical activity is necessary to maintain a healthy weight and stay fit. Remember that the body uses food as an energy source, so energy requirements determine how well the body metabolizes the food we eat and absorbs the nutrients from it. When your food intake and level of physical activity are not balanced, you gain weight and develop health issues. 

Exercise is particularly beneficial in maintaining healthy blood pressure and proper blood circulation. A few studies have also found that exercise can help increase hemoglobin levels and, therefore, the oxygen-carrying capacity of the blood.

Maintaining Blood Health

Over time, people have come to understand the importance of regular exercise for heart and lung health. Now, it's time for people who want to better their ability to move, such as athletes and fitness enthusiasts, to pay more attention to their blood health and the various ways it contributes to optimizing one's athletic performance.