During the first 15 seconds of intense exercise, such as sprinting or power lifting, most of the energy is provided by
A) fat oxidation.
B) carbohydrate oxidation.
C) ATP in muscle fiber.
D) phosphocreatine.
E) ATP in muscle fiber and phosphocreatine.

Question

Quizplus · Accepted Answer

During the first 15 seconds of intense exercise, the body primarily uses ATP stored in muscle fibers and phosphocreatine for energy. These energy sources provide the quick burst of energy needed for short, intense activities.

During the First 15 Seconds of Intense Exercise, Such as Sprinting