With the World Cup over and the Commonwealth games just beginning it is set to be another sporting summer. But what does it take to be a world class sporting star? Sure, training is crucial but the diet of the sportsmen and women are also tightly regulated. Impact Science looks into the diets of the biggest athletes in the world and where their energy comes from.
The calorie contents of athlete’s diets vary dramatically depending on the sport. It was well documented that Michael Phelps ate over 12,000 calories a day- this included three fried egg sandwiches, choc chip pancakes, a five egg omelette, cereal and French toast – just for breakfast. Olympic rowers training three times a day must consume 6000 calories whilst females undertaking taekwondo must eat only 1,500 calories. This requires sticking to meticulously regulated diets.
Pasta was a popular choice at the World cup with the Italians even bringing their own with them.
Athletes must eat complex carbohydrate laden foods with guidelines stating for every kg of bodyweight a player should have 1 to 4 grams of carbs. Foods high in carbohydrates build up stores of glycogen in the liver which provides the fuels to sustain athletes. Carbohydrates are ranked by their glycaemic index (GI). This is a score of the rate at which foods are broken down into sugar which is used to raise glucose levels. Foods with low-glycaemic index, such as bread, pasta and potatoes, should be eaten as they are broken down slowly and release sugar gradually over time. Three hours before a match players are advised to eat a meal rich in carbohydrates which provides them with the energy to last the full match. Pasta was a popular choice at the World cup with the Italians even bringing their own with them. During the Olympics over 25,000 loaves of bread and 232 tons of potatoes were brought into the Olympic village, along will 330 tons of fruit and vegetables.
With alcohol out of the picture during the World Cup due to it causing dehydration, one popular drink proved to be chocolate milkshake which provides nutrients to help recovery after games, over 75,000 tons of milk was also supplied to the Olympic village.
Sweets and soft drinks are not advised for athletes as they prevent the body from burning fat.
Protein is also an important part of an athlete’s diet as it helps with recovery of muscles after long periods of exercise. Proteins are obtained in the diet from meat, dairy, chicken and pulses. It is advised that 1 g of protein is eaten per kg body weight for an athlete.
One sight common at any sporting event is sports stars sipping different types of branded sports drinks. Sports drinks contain fluids, electrolytes and carbohydrates. There are three different types of sports drinks: isotonic which have the same concentration of salt and sugar as the body and are used to resupply fluid and carbohydrates, hypertonic which contain higher concentrations of salt and sugar as the body and hypotonic which contain lower concentrations of salts and sugars.
While eating a large amount of simple carbohydrates such as sweets and soft drinks are not advised for athletes as they prevent the body from burning fat, they are an extremely useful energy boost during games as they have high glycaemic content so are rapidly broken down to provide a burst of energy which lasts for a short time. Fats are also an important energy source when glycogen has been used up.
However, it’s not just about eating the right foods whilst training. Before a match, food preparation is key. This requires steadily increasing the amount of carbohydrate in the diet throughout the week. Having less carbohydrates at the start of the week means that muscles produce more GLUT-4 receptors which have been shown to absorb carbohydrates. This means that closer to an event athletes increase the amount of carbohydrate in the diet. This increases the amount of stored glycogen so there is more energy available.
So although eating 12,000 calories a day, although tempting, is not a healthy life style choice for us normal people, it is clear that a strictly regulated diet is one of the most important parts of training to be an athlete.