Which term best describes agility in fitness?

Agility in fitness refers specifically to the ability to change directions quickly and effectively while maintaining control. This skill is crucial in various sports and physical activities that require rapid movements and adjustments to positions, such as basketball, soccer, and tennis. Being agile involves coordination, balance, and speed, enabling an individual to navigate their environment efficiently while avoiding obstacles or responding to dynamic situations.

The other choices address different aspects of physical fitness. Endurance refers to the ability to sustain physical activity over an extended period, primarily focusing on cardiovascular and muscular stamina. The capability to lift heavy weights pertains to strength and power, emphasizing the ability to exert maximum force in lifting tasks. Speed in sprinting relates to the rapid execution of movement over a short distance, which is distinct from the multi-directional capabilities inherent in agility. Therefore, "the ability to change directions quickly" encapsulates the essence of agility in fitness.