Approximately what percentage of water constitutes muscle mass?

Muscle mass is made up of a significant amount of water, which is essential for various physiological functions including nutrient transport, temperature regulation, and metabolic processes. Typically, muscle tissue is composed of about 70% to 75% water by weight, with many sources commonly citing a figure of around 72%. This high percentage reflects the importance of hydration in maintaining muscle performance and overall bodily functions.

The other options do not accurately represent the biological composition of muscle mass. For instance, percentages lower than 70% do not account for the extensive role that water plays in muscle structure and function, while a figure that is too high, such as 80%, overestimates the water content in muscle tissue. Thus, the most accurate approximation of water content in muscle mass is around 72%, making it the correct response for this question.