FOR AND AGAINST SUPPLEMENTATION FOR PERFORMANCE: Vitamins: -Vitamins are required in only very small quantities in the body, and if eating a balanced diet supplementation unnecessary. -The intake of excessive quantities of vitamins is not only unnecessary but potentially dangerous. -It is known that super-supplementation does not improve performance. Minerals: -Iron and calcium are the two main minerals that are most commonly deficient in athletes and inadequate supplies will affect performance and contribute to health problems. - (Iron- found in heamoglobin) Diminished heamoglobin levels affect performance because the muscles are deprived of oxygen, which is needed to break down the nutrients and produce energy. -‘Sports anemia’ is a condition commonly associated with activity, yet a balanced diet is an excellent source of iron. -Athletes should look to dietary sources rather than supplementation. Protein: -On the whole, research supports the idea that most athletes do not need or benefit from protein supplementation as athletes are well supported by a balanced diet. -Surveys reveal that most athletes consume well in excess of 1.2-2.0 g/kg (people only require 1 gram per kilogram of body weight), making supplementation both needless and wasteful. -In addition, many protein supplements contain additives that have no health benefits and may increase the risk of some cancers. -Furthermore, excess protein can negatively affect health as in high amounts; the amounts of calcium excreted in the urine increases and may possibly contribute to osteoporosis. -Despite this, protein supplements have had a strong favour with weight-lifters, body builders and strength athletes, as they believe that protein supplements are important because of their muscle building qualities, with higher intake positively affecting muscle size. Caffeine: -Caffeine has ergogenic aid properties, which means that it improves performance by assisting specific metabolic processes. -In the case of endurance performance, it is the ability of caffeine to mobilise fat stores in the body and convert them into free fatty acids. Working muscles oxidise free fatty acids, making them a usable source of energy. It is believed that caffeine promotes ‘glycogen sparing’, a process whereby fat is metabolized early, sparing finite reserves of glycogen and subsequently prolonging the point at which exhaustion will occur. -Some studies report that caffeine may contribute to dehydration. However, the link with dehydration is not well supported. Creatine products: -While manufactures of creatine products continue to market its performance enhancing properties, including increasesing strength, delaying fatigue and burning fat, research has found very little, if any benefit. -The body is unable to store excess amounts of creatine, so supplementation has little effect on athletes who already consume high amounts of protein. -Where muscle creatine storage levels are low e.g. in case of vegetarians, there may be case for limited supplementation. -Some uses of creatine products believe the substance might be directly related to muscle cramps and increases in weight. -Positive side, research has established that muscle hypertrophy is more easily achieved when training is assisted by creatine supplementation. -While there is probably no harm in small doses for exercising athletes, larger doses of creatine may have health risks including the possibility of developing renal disease.