Why? The Science of Athletics

3 I 6 WHY?-THE .SCIENCE OF ATHLETICS source of heat. Carbon is more highly concentrated in fat than elsewhere, and fat occurs most lavishly in meat, milk and fish. Such cereals as maize and oats ; nuts ; and such vegetable products as olive oil, have also high fat contents. Carbohydrates are found almost entirely Carbohydrates in vegetables, comprise no more than I per cent of body weight, and yet are a very real source of energy. They are easily absorbed, and in com– pany with fat from the fat foods supply, as explained earlier, a valuable reserve store of energy. The value of the carbohydrates is found in their various contents, the first of which is the sugar in vegetables, fruit juices, and in milk as lactose. Then, the starches from cereals and potatoes and cellulose, or fibre of plants, which aids digestion by stimulating the peristaltic action of the stomach and intestines. Carbohydrates occur in the following approximate percentages in some usual foodstuffs : Milk, 4 to 5 per cent; oranges, 8·7 per cent; bananas, 22·7 per cent; raisins, such as one so often sees athletes munching while waiting to compete, 68· 5 per cent ; and wheat flour 70· 3 per cent. Vitamins Mention has' been made already of milk in relation to vitamin content, but very few food-stuffs have them all. They are not produced in the body of the animal, but come from the food supplied in the first place by plants, and in many cases plants which have enjoyed a wealth of sunlight. Heat and air p.re believed to be destructive of vitamin values, and the use of soda in cooking is also destructive to them. Vitamin A is very necessary to the athlete, since its absence from his diet will mean loss of weight. It is not found in lard, but is present in meat-fats, in conjunction with Vitamin D, while cod-liver oil contains two hundred and fifty times as much of Vitamin A as butter. Vitamin B, again, is essential to the athlete, because