Aerobic exercise like jogging causes changes in skeletal leg muscles, such as
A) increasing hemoglobin in fast-twitch muscles.
B) decreasing the number of mitochondria in the muscle cells.
C) decreasing the enzymes involved in energy utilization.
D) increasing the density of capillaries.
E) increasing the number of glycolytic muscle fibers.

Question

Quizplus · Accepted Answer

Aerobic exercise causes an increase in the density of capillaries in skeletal leg muscles, which improves blood flow and delivery of oxygen and nutrients to the muscle cells. Option A is incorrect because hemoglobin is a protein that binds oxygen in red blood cells, not found in muscle cells. Option B is incorrect because the number of mitochondria increases with regular aerobic exercise, allowing for more efficient energy production. Option C is incorrect because aerobic exercise increases enzymes involved in energy utilization, such as those in the citric acid cycle and oxidative phosphorylation. Option E is incorrect because aerobic exercise primarily affects slow-twitch fibers, which are more oxidative and rely on oxygen for energy production, rather than the glycolytic fibers which rely on glucose.

Aerobic Exercise Like Jogging Causes Changes in Skeletal Leg Muscles