Minerals

Minerals are often forgotten when trying to get a good balanced diet, but there importance can not be stressed enough. In this section all the minerals won't be talk about in detail but they can be seen in the table below. Minerals make up approximately 5% of total body weight, however most of this consists of bone (calcium). Sufficient calcium is vital to our health. If we have a lack of calcium in our diet then the body will remove it from storage sites such as bones. As well as playing an important role in the formation of bones, calcium plays essential roles in muscle contraction, function of the nervous system, blood clotting, and control of membrane permeability. Good sources of calcium are milk and other dairy products. The recommended daily allowance (RDA) of calcium is 1,200mg.

Phosphorus is closely linked to calcium. About 80% of phosphorus is found in combination with calcium in the form of calcium phosphate. Phosphorus plays an important role in the body's metabolism, cell membrane structure, and the buffering system to maintain a constant blood PH. Without phosphorus it would almost be impossible to move. This is because it is an essential part of ATP. Good sources of phosphorus are meat, poultry, fish, eggs, and milk. The RDA for phosphorus is 1,200.

Iron is present in the body in relatively small amounts compared to the previous two minerals. However it plays an extremely critical role in the transportation and storage of oxygen. This is because it is contained within the proteins haemoglobin and myoglobin. Haemoglobin transports oxygen in the blood and myoglobin is found within muscle cells, which transports and stores oxygen within the muscle fibres. Lack of iron in the diet can lead to lack of energy due to the decreased efficiency of the body's ability to transport oxygen and in serious cases anemia. However this must not be confused with the normal feeling of tiredness brought on by intense training. The best source of iron is liver, however lean meat leafy green vegetables and egg yolks are also god sources. Vitamin C helps the absorption of iron. The RDA for iron is 15mg in women and 10mg in men.

Sodium, potassium and chloride are classified as electrolytes and are found distributed throughout the body. Sodium and chloride are found predominantly outside the cells and potassium is distributed mostly within cells. The selective distribution of these three minerals establishes the separation of electrical charge across nerves and the muscle cell membrane. This means that these minerals enable neural impulses and muscle activity. These minerals are also involved in the maintenance of water distribution and balance as well as normal cardiac rhythm (heart beat), and acid base balance. Lack of sodium is unlikely in your diet however lack of potassium can cause weakness of the muscles and an abnormal electrocardiogram. Major sources of sodium chloride are table salt, seafood, milk, and meat. Potassium is found most readily in fruits, milk, meat, cereals, and vegetables.

Swimmers who eat a good balanced diet are unlikely to become mineral deficient. However the importance of minerals cannot be stressed enough.