Physical fitness is to the human body what fine-tuning is to an engine. It enables us to perform up to our potential. Fitness can be described as a condition that helps us look, feel, and do our best. More specifically it is: The ability to perform daily tasks vigorously and alertly, with energy left over for enjoying leisure-time activities and meeting emergency demands. It is the ability to endure, to bear up, to withstand stress, to carry on in circumstances where an unfit person could not continue, and it is a major basis for good health and well-being.

Physical fitness involves the performance of the heart, lungs, and muscles. Since what we do with our bodies also affects what we can do with our minds, fitness influences to some degree qualities, such as mental alertness and emotional stability.

Before starting an exercise program
Get your doctor's OK!

The Basics

Physical fitness is most easily understood by examining its components or parts. The five ingredients are:

1. Cardio respiratory endurance - the ability to deliver oxygen and nutrients to tissues, and to remove wastes, over sustained periods of time.
2. Muscular strength - the ability of a muscle to exert force for a brief period of time. 
3. Muscular endurance - the ability of a muscle, or a group of muscles, to sustain repeated contractions or to continue to apply force against a fixed object. 
4. Flexibility - the ability to move joints and use muscles through their full range of motion. The sit-and-reach test is a good measure of flexibility of the lower back and backs of the upper legs.
5. Body composition - is considered a component of fitness. It refers to the makeup of the body in terms of lean mass (muscle, bone, vital tissue, and organs) and fat mass. An optimal ratio of fat to lean mass is an indication of fitness. The right types of exercises will help you decrease body fat and increase or maintain muscle mass.