POWERS OF THE HUMAN BODY
The human body is made up mainly of bone, muscle and fat. Some 639 different muscles make up about 45 per cent of the body weight. Each of these muscles has four different and measurable qualities. It can produce force which can be “measured as strength of muscle. It can also store energy which permits it to work for extended periods of time independent of circulation.
In addition, a muscle can shorten or be stretched. The combination of these four qualities of muscle is referred to as muscular power. If muscles are to function efficiently, they must be continually supplied with energy fuel. This is accomplished by blood, which carries the energy fuels from the lungs and digestive system to the muscles.
The blood is forced through the blood vessels by the heart. The combined capacity to supply energy fuels to the working muscles is called organic power. The capacity and efficiency with which your body can function depend on the degree of development of both your muscular and organic powers through regular exercise.
However, the level to which you can develop these powers is influenced by such factors as the type of body you have, the food you eat, presence or absence of disease, rest and sleep. You are physically fit only when you have developed your muscular and organic power. Genetics and health determine the top limits to which your physical capacity can be developed. This is known as your ‘potential physical capacity’. This potential capacity varies from individual to individual.
Most of us, for example, could train for a lifetime and never come close to running a four-minute mile simply because we weren’t built for it. The top level at which you can perform physically right now is called your ‘acquired capacity’ because it has been acquired or developed through physical activity in your daily routines. You can avoid wastage of energy by acquiring a level of physical capacity well above the level required to perform your normal daily tasks. This can be done by supplementing your daily physical activity with a balanced exercise program performed regularly.
Your capacity increases as you progressively increase the load on your muscular and organic systems.