Fitness Definitions

1) Health-Related Physical Fitness

Health-related physical fitness consists of those components of physical fitness that have a relationship with good health. The components are commonly defined as body composition, cardiovascular fitness, flexibility, muscular endurance, and strength.

• Body Composition: The relative amounts of muscle, fat, bone and other vital parts of the body.
• Cardiovascular Fitness: Ability of the circulatory and respiratory systems to supply oxygen during sustained physical activity.
• Flexibility: The range of motion available at a joint. Note: Some experts specifiy that flexibility requires range of motion without discomfort or pain.
• Muscular Endurance: The muscle's ability to continue to perform without fatigue.
• Strength: Relates The ability of the muscle to exert force.

2) Skill-related Physical Fitness

Skill-related physical fitness consists of those components of physical fitness that have a relationship with enhanced performance in sports and motor skills. The components are commonly defined as agility, balance, coordination, power, speed and reaction time.

• Agility: The ability to rapidly change the position of the entire body in space with speed and accuracy.
• Balance: The maintenance of equilibrium while stationary or moving.
• Coordination: The ability to use the senses, such as sight and hearing, together with body parts in performing motor tasks smoothly and accurately.
• Power: The ability to the rate at which one can perform work.
• Speed: The ability to perform a movement within a short period of time.
• Reaction Time: The time elapsed between stimulation and the beginning of the reaction to it.

3) Physiological Fitness

Physiological fitness includes non-performance components of physical fitness that relate to biological systems that are influenced by one's level of habitual physical activity.

4) Metabolic Fitness

The state of metabolic systems and variables predictive of the risk for diabetes and cardiovascular disease which can be favorably altered by increased physical activity or regular endurance exercise without the requirement of a training-related increase inV•O2max.

5) Morphological Fitness

A non-performance component of fitness related to body composition factors such as body circumferences, body fat content, and regional body fat distribution.

Other articles in this series:

- Fitness Intro
- Physical Activity
- The Fitness Fomula
- Make Exercise a Habit

References:

• U.S. Department of Health and Human Services
• Health Fitness Instructor's Handbook; Edward Howley, B. Don Franks
• President's Council on Physical Fitness and Sports Research
• Skill-related fitness for sports success; Dr. George R. Colfer
• Surgeon General's Report on Physical Activity and Health
• Federal Citizen Information Center
• American College of Sports Medicine
• What is fitness?; CrossFit Journal