Notes

Cardiorespiratory endurance is the efficiency with which the body delivers oxygen and nutrients to its cells. Proper and efficient delivery is important to healthy muscle activity and removing cellular waste.
Muscular strength refers to the greatest amount of force that a muscle or muscle group can put forth in a single effort; it is gained over time.
Muscular endurance is how well a muscular group performs repeated movements for extended periods of time.
Flexibility is the ability to move joints through an entire range of motion.
Body composition is the percentage of a person's body fat compared with the total body mass.

While the words exercise and fitness are sometimes used interchangeably, they actually have different meanings. Physical exercise is the act of improving one's body through specific intentional movements. Fitness is the ability of the body to function effectively and efficiently during physical activity. The difference between the two words is important: while anyone can exercise, only someone who exercises regularly can be fit.

Physical fitness can be broken into two main categories: health-related fitness and skill-related fitness. Both health- and skill-related fitness are types of fitness that focus on performance, or how the body completes a physical activity.

Health-related fitness is made up of the five components of physical fitness: cardiorespiratory endurance, muscular strength, muscular endurance, flexibility, and body composition. These components have a close relationship with good health. Good health-related fitness lowers the risk of illness and can improve the overall quality of life.