Saturday, 26 July 2014

defination of health

Definition of Health
To many people, health means absence from illness. However, according to the World Health Organization (WHO, 1948),
"Health is a state of complete physicalmental and social well-being and not merely the absence of disease or infirmity."[1]
The definition has not been amended since 1948.

[1] Preamble to the Constitution of the World Health Organization as adopted by the International Health Conference, New York, 19-22 June, 1946; signed on 22 July 1946 by the representatives of 61 States (Official Records of the World Health Organization, no. 2, p. 100) and entered into force on 7 April 1948.
Definition of Fitness
Physical fitness is generally defined as "the ability to carry out daily tasks with vigor and alertness, without undue fatigue, and with ample energy to enjoy leisure-time pursuits and to meet unforeseen emergencies."  (USDHHS, 1996)
It is fundamental to health. It must be improved through long-term and regular participation in exercises, as well as maintaining a healthy lifestyle. Physical fitness can also be classified into two categories: (1) health-related fitness and (2) sport-related fitness.
Components of health-related fitness, also generally known as physical fitness, include cardio-respiratory endurance, muscular strength and muscular endurance, flexibility, body composition, and neuromuscular relaxation.
  1. Cardio-respiratory Endurance refers to the ability of the circulatory system and the respiratory system (i.e., heart and lungs) to supply oxygen to the working muscles and remove metabolic wastes (e.g., carbon dioxide) at the same time.
    • It is the most important component of health-related fitness because the human body and the brain must have sufficient oxygen supply to work normally. The more sufficient the oxygen supply, the more efficient the different body parts can work.
    • According to Mazzeo and his co-workers (1998), the capacity of the heart to pump blood and the body to absorb oxygen reduces 5% to 15% every 10 years after the age 25. However, participate regularly in endurance training is undoubtedly beneficial to cardio-respiratory efficiency.
  2. Muscular Strength refers to the maximum force that can be produced by a muscle or muscle group in a single contraction (i.e., 1-RM*)[1], and muscular Endurance refers to the ability of the muscles to contract repeatedly, or maintain  a submaximal force for an extended period of time.
    • Heavier workloads cannot be overcome with insufficient muscular strength and endurance, which may also lead to premature muscular fatigue and muscular pain. Besides, insufficient muscular strength and endurance is also a factor of sport injuries, or other chronic musculo-skeletal injuries.
    • Elders may also tumble easily because of weak muscular strength and endurance.
  3. Flexibility refers to the ability of a joint or a series of joints to move through its full range of movement.
    • With better flexibility, movement can be performed at higher efficiency (e.g., hurdling). Besides, good flexibility also helps to prevent sport injuries (e.g., strains).
    • Poor flexibility may also lead to lower back pain problems associated with aging.
  4. Body composition refers to the proportion of fat to non-fat components (i.e., bones and muscles) in the human body.
    • Obesity is not only detrimental to sports performances; it will also increase the chances for suffering from cardiovascular diseases.
  5. Neuromuscular relaxation refers to the ability to reduce or even eliminate unnecessary tension or contractions of muscles due to stress.
    • Being able to relax not only enables one to work more efficiently, but also facilitates sport performances.

    [1] RM (Repetition Maximum) refers to the maximum number of time(s) one can lift a given weight. 1-RM is the weight that can be lifted for only once.
Sport-related fitness is the ability for athletes to improve in their performances or results. In additional to the basic components of health-related fitness, components of sport-related fitness also include:
  • Agility
  • Balance
  • Coordination
  • Reaction Time
  • Speed
  • Power