Question

question 49
the performance capacity of muscle is determined by which of the following nontrainable factors:
○ fiber diameter
○ nerve impulse frequency
○ capillary density of muscle
○ number of fibers

Explanation:

1. Fiber diameter: Can be altered through training (e.g., hypertrophy increases fiber diameter), so it is trainable.
2. Nerve impulse frequency: Training can improve neural adaptations, including changes in nerve impulse frequency for better muscle activation, so it is trainable.
3. Capillary density of muscle: Endurance training can increase capillary density to improve oxygen delivery, making it trainable.
4. Number of fibers: The number of muscle fibers an individual has is determined genetically and is generally non - trainable (one is born with a set number, and training does not increase this number).

Answer:

D. number of fibers