By Esther Teo

Olympic champ Michael Phelps' 12,000 calories a day diet could kill you.

BBC News reported that his breakfast consists of three fried egg sandwiches with cheese, tomatoes, lettuce, fried onions and mayonnaise, three chocolate-chip pancakes, a five-egg omelette, three sugar-coated slices of French toast, a bowl of grits and two cups of coffee.

Lunch involves half a kilogram of enriched pasta, two large ham and cheese sandwiches with mayonnaise on white bread and energy drinks,

His winning appetite is capped with half a kilogram of pasta with carbonara sauce, a large pizza and more energy drinks for dinner.

His breakfast alone is probably more than what you eat all day.

This is in stark contrast to the recommended 2,500 to 3,000 calories daily that the United States Food and Drug Administration recommends for men according to varying age and activity level.

Phelps is estimated to burn 1,000 calories per hour during swimming training and with a training schedule that lasts five hours a day, six days a week, his seemingly outrageous appetite can definitely be excused.

So can many of the other athletes in the Olympics who have diets fashioned especially for them. Even the more unorthodox meals have been consumed for the sake of Olympic glory, such as bull's penis soup by the Chinese rowing team.

While endurance sports like swimming and long distance athletic events require high amounts of carbohydrates for sustained energy, others such as gymnastics require high levels of protein instead for the short bursts of energy needed in the sport.

Ms Nicola Porter, a nutritionist with Singapore-based nutrition and image consultancy firm Nutri-Style, said that a diet well-suited to an athlete's need would allow him to maximise energy levels, maintain an appropriate body composition and perform optimally in competitions.

'It also ensures that they recover fully after an event and improves immune function, helping to avoid injuries and infections,' she added.

These diets are usually derived based on the energy requirements of the sport and the nutritional requirements that have been found to help performance, said MrGobinathan Nair, assistant director of the Sports Science Academy at the Singapore Sports School.

He said that the individual characteristics particular to each athlete such as his sex, age and training status also come into play.

We break down the dietary needs of five different sports and the nutrition science behind it.

SWIMMING

Diet: High carbohydrate, high energy.

Why: Carbohydrates are the food that muscles burn. With a swimmer's intensive training schedule, a high carb diet will allow him to recover faster. A lack of carbohydrates will result in failure to recover adequately, leading to fatigue, loss of body weight and poor performance.

Did you know: Phelps, with his muscular physique and high metabolism, would probably burn more calories just sitting than a lot of people burn walking, reported BBC News.

Michael Phelps is estimated to burn 1,000 calories per hour during swimming training six days a week, five hours daily.

US gymnast Nastia Liukin goes for a high protein diet

GYMNASTICS

Diet: Low carbohydrate, high protein.

Why: Gymnastics is considered a sport in which short, intense bursts of power are more crucial than stamina. MSNBC reported that the longest gymnastics routine - the floor exercise - lasts only between 70 and 90 seconds. Thus, complex sugars produced by carbohydrates are not as vital as a high protein diet which is key to providing short bursts of energy. Most gymnasts get 60 to 70 per cent of their calories from proteins and the rest from carbs and fats, reported the Associated Press.

Did you know: Gymnastics has been criticised for encouraging eating disorders as gymnasts often have to watch their diets closely in their quest to achieve their lean, muscular bodies.

MARATHONS

Diet: High carbohydrate, moderate protein, plenty of antioxidants.

Why: Peak Performance, a sporting excellence website, recognises carbohydrates as one of the most important foods as they provide a distance runner the fuel to sustain him in endurance events. Stored in the body as glycogen, it is converted to glucose to provide energy for the body while he is exercising. Protein is also essential for maintaining energy levels as some protein is used during exercise. Thus, as endurance athletes, runners need a bit more protein than usual. Channel4, a British website, also recommends antioxidants, which are found in fruits and vegetables, because athletes produce a lot of free radicals - which cause cell damage - during intensive exercise.

Did you know: Active.com reported that Kenyan runners, known to be the best endurance athletes, obtain most of their nutrients from vegetable sources, with only 14 per cent coming from animal sources.

WEIGHTLIFTING

Diet: High protein, moderate carbohydrate.

Why: Independent UK TV Channel4 reported that a power sport such as weightlifting requires a very high protein diet as intense exercise increases demand for protein, which supports muscle repair and growth. Weightlifters often train just above their weight category, then cut back on their carbohydrates a few weeks before the competition to lose fat but not muscle mass.

Did you know: Reuters reported that 19-year-old German weightlifter Julia Rohde had a strict energy-conserving regime that did not even allow her to walk down the road. Already on a 'diet' so as to enter a lower weight class, her minders were worried that she might shed her weight too quickly and lose valuable muscle mass.

SPRINTERS

Diet: High protein, moderate carbohydrate.

Why: The Australian Institute of Sport says that sprinters need high power outputs and low body fat levels while developing both large and powerful muscles. Therefore, they consume enough carbohydrates to meet the demands of their training needs but not to the extent that endurance-type athletes such as swimmers consume. As they are strength athletes, a high protein diet allows for the development of muscle mass.

Did you know: Jamaican Usain Bolt (Picture 3), world record holder of the 100m sprint, snacked on McDonald's chicken nuggets to prepare for his race.

esthert@sph.com.sg

This article was published in Mind Your Body, The Straits Times on August 21, 2008.

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