Human muscles have an efficiency of about _

A. 9 to 17%

B. 18 to 26%

C. 27 to 35%

D. 36 to 44%

B. 18 to 26%

Explanation:

The efficiency is low because most of the energy is lost when food energy is converted into ATP (adenosine triphophate). It is estimated that human muscles have an efficiency of about 18% to 26%. The muscle efficiency is calculated by dividing mechanical work output by total metabolic cost.