Question

3. Muscles respond to strength training with hypertrophy. Hypertrophy occurs by a) increasing the number of muscle fibers in the skeletal muscle. b) increasing the diameter of each fiber by adding more myofibrils. c) adding more mitochondria and myoglobin to each fiber. 4. Endurance training (such as training to run a 10k race) aims to increase the % of ATP generated from aerobic respiration during times of intense exercise. Which fiber type is primarily recruited for this type of endurance activity? b) fast twitch oxidative a) slow twitch fast twitch glycolytic. c) 5. Therefore, endurance training induces these fibers to a) hypertrophy. b) switch to a different fiber type. increase # of mitochondria & myoglobin c) 6. It is common knowledge among athletes that weight lifters do not make good endurance runners. Using your knowledge of muscles, explain why.

Answer 1

3. b) Increasing the diameter of each fiber by adding more myofibrils.

The hypertrophy involves an increase in skeletal muscle size through a growth in component cell size. The diameter of muscles are increased through the parallel addition of myofibrils. The increase in the amount of myofibrils within the muscle fiber causes growth. It is the enlargement of skeletal muscle fiber by the increase in mass or amount of component cells to accumulate more structural contractile proteins by continues physical exercises or trainings: weight lifting.