What term describes the body's ability to function efficiently and effectively?

The term that best describes the body's ability to function efficiently and effectively is "physical fitness." Physical fitness encompasses a range of attributes that contribute to overall health and well-being, including endurance, strength, flexibility, and body composition. When an individual is physically fit, they can perform daily activities with vigor and ease, reflecting an optimal level of health and fitness.

In contrast, muscular strength specifically refers to the amount of force a muscle or group of muscles can exert, which is just one component of physical fitness. Body composition involves the ratio of fat to lean mass in the body, providing insights into overall health but not encompassing the full idea of functional efficiency. Cardiovascular efficiency pertains to the effectiveness of the heart and lungs in supplying oxygen during physical activity, but it is only one aspect of the broader concept of physical fitness. Hence, physical fitness captures the overall ability of the body to function at a high level of efficiency and effectiveness.