Physical fitness refers to the ability to perform daily tasks with alertness and vigor. There are two main components of physical fitness - health-related fitness and skills-related fitness. Health-related fitness includes cardio-respiratory endurance, muscular strength, flexibility, muscular endurance, and body composition. Skills-related fitness includes coordination, speed, balance, power, agility, and reaction time. The document discusses the definitions of various aspects of physical fitness and provides examples of tests to measure components of health-related fitness.