What proportion of total body water is intracellular?

The correct answer regarding the proportion of total body water that is intracellular is found in the choice that states it is about 3/4. This means that approximately 75% of total body water exists within the cells of the body, which is a key aspect of cellular function, as water is crucial for maintaining cell shape, facilitating biochemical reactions, and transporting nutrients and waste products.

Intracellular water is vital for maintaining homeostasis and is involved in numerous physiological processes such as nutrient absorption and gas exchange. Understanding this proportion is essential for fitness nutrition and hydration strategies, as it guides professionals in advising clients about fluid intake and hydration practices critical for optimal performance and health maintenance.

In contrast, the other options present incorrect proportions that do not align with physiological data regarding body water distribution.