Question

What is the preferred substrate by the body for energy at rest? How does this change with exercise?

a) Protein is the preferred substrate at rest, and it remains the same during exercise
b) Carbohydrates are preferred at rest, and fats become more important during exercise
c) Fats are preferred at rest, and this preference continues during exercise
d) The body has no preferred substrate for energy

Answer 1

Fats are the preferred energy substrate at rest, while carbohydrates become more prominent during exercise, particularly at higher intensities.

Step-by-step explanation:

The body's preferred substrate for energy at rest is fats. This is because fats provide a more efficient, long-term energy source for low-intensity activity and are abundant in supply within the body's adipose tissue. However, with exercise, particularly at moderate to high intensities, the body shifts its energy preference. Carbohydrates become the principal source of fuel during high-intensity exercise because they can be metabolized more quickly than fats, providing the quick energy needed to maintain such activities. As exercise duration continues and intensity decreases, the body then shifts towards burning more fats. It is important to note that while protein can be used as an energy source during periods of severe energy depletion, it is not a preferred energy source during rest or exercise, as proteins are critical for building and repairing tissues.