What is Health? Health is not merely the absence of disease. The dimensions of health encompass physical, psychological, emotional, intellectual, occupational, social, spiritual, and environmental aspects of life.

What is Physical fitness? It's the capability of the heart, lungs, blood vessels, and muscles to function at optimal efficiency. A fit person should be able to carry out any daily activities without undue fatigue,  to enjoy life, and still to have ample reserve energy to respond to unforeseen emergency or crisis situations.
Physical fitness can be divided into two groups: health-related and skill-related fitness.

1. Health-Related Fitness consists of 5 components: Cardiovascular Endurance, Muscular Strength, Muscular Endurance, Body Composition, and Flexibility.

2. Skill-Related Fitness consists of all 5 components of health-related fitness, plus Speed, Agility, Power, Balance, Stability, Reaction time, and Coordination.

Not a single activity or sport can develop all the components of physical fitness. For this reason, cross-training is very important for individuals who would like to get fit (based on the physical fitness definition described above). A fit person may not be a healthy person. Nonetheless, a fit person may feel healthy because he or she is more likely to be more successful in accomplishing the dimensions of health. It is tremendously difficult for a person to stay on top of his or her physical condition for a long period of time because physical fitness often requires a good positive attitude, mental focus, concentration, and toughness.