You didn't specify who you wanted the “average muscle percentage” for. Here are some averages for various adults that are of a normal weight.
Women that don't exercise, have fairly sedentary lifestyles have an average of about 24% of their weight in muscle. With a moderately active lifestyle it can go up to around 30%. High amounts of muscle, such as a weight lifter, can be as high as 35% of weight. Anything over 35% is considered extremely high, typical of competitive bodybuilders.
<em>As Karen is preparing to present her research paper in her psychology class, she is filled will fear. She starts to sweat, and she notices that her mouth is very dry. Physiologically, Karen is experiencing the fight response that is activated by her sympathetic nervous system. </em>
