Final answer:
During cellular respiration in an athlete's body, inputs of oxygen and glucose are converted into outputs of carbon dioxide, water, and energy.
Step-by-step explanation:
During cellular respiration in an athlete's body, the inputs of matter are oxygen and glucose, and the outputs of matter are carbon dioxide, water, and energy. The body takes in oxygen from the air we breathe and glucose from the food we eat. These substances are then converted through a series of chemical reactions into carbon dioxide and water, which are released as waste products, and energy in the form of adenosine triphosphate (ATP), which is used by cells for various functions.