Question

At the beginning of exercise, the primary determinant of the energy system used is____.

a) Oxygen availability
b) Glucose levels
c) Lactic acid production
d) ATP synthesis

Answer 1

The primary determinant of the energy system used at the beginning of exercise is oxygen availability.

Step-by-step explanation:

The primary determinant of the energy system used at the beginning of exercise is a) Oxygen availability. Initially, during increased exertion, muscle glycogen is broken down to produce glucose, which undergoes glycolysis to produce pyruvate. Pyruvate can then be used to produce ATP in aerobic respiration if oxygen is available or used in anaerobic respiration if oxygen is not available.