What best describes agility in physical fitness?

Agility in physical fitness is best defined as the ability to change body position quickly and effectively while maintaining control. This skill is crucial in many sports and physical activities where rapid directional changes and quick reactions to dynamic environments are required. Agility encompasses coordination, balance, and speed, allowing individuals to maneuver efficiently while avoiding obstacles or responding to opponents.

The other options encompass different aspects of physical fitness but do not pertain to agility specifically. For instance, lifting heavy weights relates to strength, performing aerobic exercises focuses on cardiovascular endurance, and maintaining endurance over time speaks to stamina. Each of these qualities plays an essential role in overall fitness, but agility distinctly emphasizes the quickness and efficiency of movement in changing positions.