What is the rate at which food is converted to energy and expended by the body?

People who utilizes the progression principle will ensure their exercise program increases in frequency, intensity, time, and type. the changes need to happen gradually in order to ensure they make gains in their fitness program. a person who doesn't utilize the progression principle can still gain health benefits from exercising, but will not continue to improve in cardiovascular fitness.

Small intestine because that is the organ which absorbs nutrients

What are the statements? a? b? c? d?