Athletes may have eGFR outside of the reference range due to large amounts of muscle mass and muscle metabolism. Due to increased amounts of creatinine in the blood, eGFR rates in athletes may be lower if the test is performed the day after a high-volume workout. In this situation, the effect is unlikely to be kidney dysfunction, but rather a larger demand on the kidneys because of high metabolic output. eGFR results should be monitored to ensure the kidneys are functioning appropriately to filter waste products in the blood.

A low white blood cell count, also called leukopenia, may mean your body cannot fight off infection, and an excessive white blood cell count (leukocytosis) may indicate an infection or inflammation. Additionally, white blood are a component of the immune system and are classified into these types: neutrophils, monocytes, lymphocytes, and eosinophils.

If the neutrophil count is high, this may be indicative of an acute infection, stress, muscle damage, rheumatoid arthritis, or other inflammatory disorders. If the neutrophil count is low, it may be the result of a bacterial infection or medical condition. A consistently low neutrophil count, in the absence of disease, may be a sign of overtraining.

Monocytes can be elevated because of an infection, inflammation, allergic reaction, or asthma. During exercise, the number of monocytes in circulation increases. However, the number of monocytes in circulation normally returns to resting levels when exercise stops. Athletes, especially endurance and female athletes, may normally have lower monocyte counts than the reference range. This is often considered an adaptation to training.

An elevated lymphocyte count may mean an infection or other immune challenge. If the lymphocyte count is low, it may be the result of a medical condition. A low lymphocyte count may also occur from under-nutrition, stress, use of corticosteroids (such as prednisone), or high exercise volumes.

If the eosinophil count is high, it could be the result of an infection, allergic reaction, eczema, or asthma. Certain medical conditions such as autoimmune diseases, hay fever, or leukemia are also associated with elevated eosinophil counts. If the eosinophil count is low, it may be the result of high levels of cortisol in the body or alcohol intoxication.

Like eosinophils, if basophil numbers climb too high, they can contribute to allergies and other inflammatory reactions in the body. A low basophil count may indicate that the athlete is unlikely experiencing an allergic response and this is generally not a cause for concern.

In medicine, triglycerides are used to monitor for conditions like diabetes or coronary artery disease. However, triglycerides can provide an important fuel during exercise. Triglycerides are a type of fat found in the blood. When you eat, your body converts any calories it doesn't need to use right away into triglycerides. The triglycerides are then stored in your fat cells. Later, when your body needs energy, hormones release the triglycerides into your blood so they can be used for fuel. This process is known as lipolysis.

People who exercise frequently tend to have lower levels of triglycerides in their blood because their bodies use more triglycerides for energy during exercise. Distance runners and other endurance athletes usually have the lowest levels of triglycerides because they use the most energy during exercise. Triglycerides are an important source of energy for athletes, helping them to maintain their performance during exercise.

Source: https://medlineplus.gov/triglycerides.html

The primary role of thyroid hormones is to regulate metabolic rate, and improper function of the thyroid gland could lead to significant decreases in athletic performance.

If TSH is high, the thyroid gland is likely not producing enough thyroid hormones or working as it should. Underactive thyroid function can affect energy levels, growth, mood, and performance. Because of fatigue, hypothyroidism can make it difficult to exercise, and your capacity to train as an athlete is significantly reduced.

When the TSH level is low, it means that the thyroid gland is overactive and producing high amounts of thyroid hormones. An overactive thyroid may make maintaining muscle mass difficult. The over secretion of thyroid hormones can have a catabolic effect on skeletal muscle tissue.

Importantly, athletes can maintain healthy thyroid hormone levels and avoid these complications with proper diagnosis and treatment.

The electrolytes, potassium and sodium, work in tandem to help maintain fluid balance and blood volume, nerve and muscle growth, heart function, and pH balance in the body. Your cells use potassium alongside sodium, and both are essential for cell function. There is a mutual trade-off between sodium and potassium to maintain balance within the body. An ion exchange occurs when sodium or potassium enters a cell. When sodium enters the cell, potassium leaves, and when potassium enters the cell, sodium leaves.

Although commonly used interchangeably, salt and sodium are not the same. Table salt is sodium chloride, a specific type of sodium obtained through the diet rather than produced naturally by the body. However, more than 70 percent of dietary sodium is obtained through packaged and prepared foods, not from table salt added while preparing or eating food.

Source: https://medlineplus.gov/potassium.html

No, there is a difference between the terms, though they sometimes seem to be used interchangeably. Anemia is caused by insufficient levels of hemoglobin, whereas a lack of iron causes iron deficiency.

It's possible to have an iron deficiency while maintaining a normal hemoglobin level despite your body’s being deficient in iron. However, a person with iron deficiency anemia has neither sufficient levels of hemoglobin nor iron. It's important to note that anemia can also be caused by issues other than iron imbalance, such as blood loss, inflammation, and certain health conditions.