What change is developed by conventional strength training in muscle fibers?

What change is developed by conventional strength training in muscle fibers?

• A. Change in size of type 2 fibers
• B. Increase in capillary density
• C. Increase in mitochondrial density in type 1 fibers
• D. Decrease in fiber cross-section area

Answer: (A)

Conventional strength training primarily causes hypertrophy in fast-twitch fibers. Lifting heavy loads creates high mechanical tension that stimulates muscle protein synthesis, especially in type II fibers, leading to an increase in their cross-sectional area. This growth of fast-twitch fibers underlies gains in strength and power. In contrast, capillary and mitochondrial adaptations are more characteristic of endurance training, particularly in type I fibers, so those options aren’t the primary change here.

Conventional strength training primarily causes hypertrophy in fast-twitch fibers. Lifting heavy loads creates high mechanical tension that stimulates muscle protein synthesis, especially in type II fibers, leading to an increase in their cross-sectional area. This growth of fast-twitch fibers underlies gains in strength and power. In contrast, capillary and mitochondrial adaptations are more characteristic of endurance training, particularly in type I fibers, so those options aren’t the primary change here.