Question

Which of the following macronutrients acts as the primary, fast-acting source of metabolic energy for an athlete's muscles during short, high-intensity sprinting sessions?

• A. \( \text{Proteins} \)
• B. \( \text{Fats} \)
• C. \( \text{Vitamins} \)
• D. \( \text{Carbohydrates} \)

Hint:

For explosive, high-intensity exercises (like sprints or weightlifting), the muscles rely on Carbohydrates for rapid energy. For prolonged endurance events (like marathons), the body transitions to burning Fats.

Answer 1

The Correct Option is D

Concept: Dietary nutrients are classified based on their primary physiological roles within an athlete's body: macro-components supply energy and build tissue, while micro-components regulate cell functions.

Step 1: Identify the primary energy resource for muscle tissue.
Carbohydrates are broken down by the digestive system into glucose, which is stored in the muscles and liver as glycogen. This glycogen can be mobilized quickly during high-intensity exercise, making carbohydrates the body's primary fuel source for fast-acting energy.

Step 2: Review the roles of alternative macronutrients.

• Proteins: Primarily used to repair, rebuild, and grow muscle tissue rather than acting as a primary energy source.
• Fats: Provide a highly concentrated energy reserve, but are metabolized slowly, making them better suited for long, low-intensity endurance activities.