Most people equate fitness with the lean and muscular bodies they see on TV, online or in health magazines. While they epitomize the ideal shape and configuration of a physically fit individual, body composition is only one part of it. Aside from this obvious physiological component, it also refers to an individual's cardiovascular endurance, strength, flexibility and stamina. A physically healthy body can be achieved through a balanced diet, regular exercise and sufficient rest.

Cardiovascular endurance, also called cardiorespiratory endurance, refers to the body's ability to sustain prolonged physical activity. Activities like walking, swimming and cycling that elevate the heart rate are examples of exercises that promote cardiovascular health. Strength, more specifically muscular strength, refers to the body's capability of applying force in any activity. Resistance training, whether through weight lifting or bodyweight exercises, develops strength. Endurance or stamina refers to the body's ability to exert itself for a long period of time without fatigue. Walking, dancing and other aerobic exercises promote muscular endurance. Flexibility refers to the body's ability to move in a wide range of motion. Stretching exercises that lengthen the muscle develop flexibility. Body composition is a measure of the amount of fat, bone, muscle and other parts of the body. It is the most obvious, although not the only, determiner of physical health.

While these factors are general measures of physical health of the general population, fitness also refers to a person's ability to perform a specific task based on his or her occupation or age group with reasonable efficiency. For example, those seeking entry to the military, air force, navy or other occupations where premium is placed on physical health must pass stringent fitness tests before being admitted. Athletes, too, must prove themselves able to handle the rigors of their sport before they can be allowed to compete. In much the same vein, there are also measures for men, women, children, the young and old alike to determine their overall physical health.

Aside from these physiological considerations, a program of overall health and wellness would not be complete without taking into consideration mental, emotional and social health. An individual who is mentally, emotionally and socially well is able to cope with the stresses of daily living without resorting to maladaptive coping mechanisms that include the use of drugs and alcohol, among others. He or she works productively and thus makes a significant contribution to his or her family and community in the process.

Moreover, a psychologically healthy individual is able to cultivate fruitful friendships and long and lasting relationships. A healthy sense of self-worth allows the physically and mentally fit person to move his or her life to its intended direction. Spirituality and religion are also important components of an overall fit and healthy individual.

Thus, a person who strives for fitness is actually gunning for more than lean and toned muscles or the ability to do more than fifty push ups. He or she is actually going for overall health and wellness, the most important component of which is physical and psychological balance. Someone who gives more importance to lifting weights than spending time with family isn't fit in the real definition of the word.