Exercise Physiology | Variation of Fuel Source with Exercise Intensity

The video explores how fuel selection changes with exercise intensity, focusing on the shift in energy source contribution from fat to carbohydrates as intensity increases. It explains absolute and relative energy expenditure, highlighting that higher exercise intensities require more energy, primarily from carbohydrates due to their efficient metabolism. The video concludes with a summary of these concepts, preparing viewers for a follow-up discussion on fuel selection variation with exercise duration.

What happens to absolute energy expenditure as exercise intensity increases?

• It decreases.

• It remains constant.

• It increases.

• It fluctuates randomly.

At 40% VO2 Max, which fuel source contributes the most to energy expenditure?

• Plasma glucose

• Muscle glycogen

• Free fatty acids

• Other fat sources

How does the percent contribution of fat change as exercise intensity increases?

• It remains the same.

• It increases.

• It fluctuates.

• It decreases.

Why do muscles prefer carbohydrates over fats at high exercise intensities?

• Fats provide more energy.

• Fats are not available at high intensities.

• Carbohydrates are easier to metabolize.

• Carbohydrates are more abundant.

Which process is more efficient for energy production at high intensities?

• Beta oxidation

• Protein synthesis

• Photosynthesis

• Glycolysis

What is the primary fuel source at low exercise intensities?

• Fats

• Proteins

• Carbohydrates

• Vitamins

What happens to the reliance on carbohydrates as exercise intensity increases?

• It decreases.

• It becomes negligible.

• It increases.

• It remains constant.