What is the term for the increase in fiber size of a muscle?

The correct term for the increase in fiber size of a muscle is hypertrophy. This process typically occurs as a response to resistance training or strength training, where the muscle fibers adapt to increased loads and stress by growing larger and stronger to handle the work required of them.

Hypertrophy results from various factors, including muscle tension, metabolic stress, and muscle damage, which stimulate the muscle fibers to repair and grow. This adaptation not only enhances muscle performance but also contributes to overall physical strength and endurance.

In contrast, hyperplasia refers to an increase in the number of muscle fibers, which is a distinct process that occurs under different conditions and is less common in human muscle adaptation. Atrophy describes the reduction in muscle size or wasting away, typically due to disuse, injury, or illness. Oligomenorrhea is unrelated to muscle physiology; it refers to infrequent menstrual periods, illustrating how both its terminology and context differ from the topic at hand.