|
Vitamins & Minerals |
||
|
ESSENTIALS
NUTRITION
LIFESTYLE
COMPETITION |
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. Vitamins
Vitamins are organic
compounds that are required in small amounts by the body to grow and
maintain health. In terms of assisting the performance only the
B-complex vitamins and vitamins C and E have been investigated. Most
vitamins have important functions that are relevant the swimmer, for
example: Ø Vitamin A is important in growth and development because it promotes bone development. Ø Vitamin D is essential for the absorption of calcium, which means it has an influence on bone development and neuromuscular activity. Ø
Vitamin K is involved in producing ATP. The B-complex vitamins
are made up of more than a dozen different vitamins. They play an
important part in the metabolism of all living cells, the oxidation of
food, and the production of energy. Complex carbohydrates are often good
sources of B-complex vitamins as well as meats. Deficiencies of
B-complex vitamins can impair performance but there has been no evidence
to show that the extra supplementation improves performance. Vitamin C is common in a
lot of the food that we eat, but deficiencies can occur in people who
smoke, use oral contraceptives, have surgery or run a fever. This
vitamin is important for the formation of good bones, ligaments, and
blood vessels. Vitamin C is also involved in: Ø Amino acid (protein) metabolism. Ø Synthesis of hormones Ø
Absorption of iron. It has been suggested
that this vitamin assists in wound healing, combating infection and
preventing the common cold. A deficiency of vitamin C can cause general
weakness, poor appetite, anemia, shortness of breath, swollen joints,
and neurotic disturbances. Exercise has been shown to produce DNA damage within cells. Vitamin E reduces the damage caused by exercise. As well as this it prevents the metabolism of vitamins A and C, which allows them to effectively be more active. Although vitamin E levels are important to maintain extra supplementation has been shown not to improve performance.
|