What is a potential benefit of strength training on muscle fiber composition?

Strength training is particularly effective at enhancing the characteristics of Type II muscle fibers, which are also known as fast-twitch fibers. These fibers are responsible for generating rapid and powerful muscle contractions, making them crucial for activities that require bursts of strength or power, such as sprinting or weightlifting.

When individuals engage in resistance training, the physiological adaptations that occur include hypertrophy (an increase in the size) of the Type II fibers as well as potential changes in their functional capacity. This adaptation helps increase overall muscle strength and power output, indicating that strength training can lead to an increase in the proportion of Type II muscle fibers as they become more prominent in response to the demands placed on them during intense physical activity.

While strength training does not necessarily decrease the overall muscle fiber count, it can alter the composition and responsiveness of those fibers, particularly by enhancing the performance characteristics of Type II fibers. Therefore, this explanation supports why the statement regarding the increase in the proportion of Type II muscle fibers is a valid benefit of strength training on muscle fiber composition.