Question

When a person begins exercising, the first metabolic fuel used is:

a) ATP and creatine phosphate.
b) fatty acids.
c) glucose.
d) stored glycogen.

Answer 1

The first metabolic fuel used when a person begins exercising is stored glycogen, which is broken down to produce glucose. This glucose is then used in aerobic respiration or converted to lactic acid depending on the availability of oxygen.

Step-by-step explanation:

The first metabolic fuel used when a person begins exercising is stored glycogen. Initially, muscle glycogen is broken down to produce glucose, which undergoes glycolysis to produce pyruvate. This pyruvate can be used in aerobic respiration to produce ATP, or when oxygen levels are low, it can be converted to lactic acid.