By Valerie Tan, Dietitian, Changi General Hospital

Sportsmen through the ages have always been preoccupied with their protein intake. The Ancient Greek Olympians were reported to have eaten a whole cow before competing while modern-day bodybuilders still swear by large portions of meat and eggs. Is there really some truth in having a higher protein intake to achieve peak athletic performance?

What is protein?
Protein is an essential part of our diet and is commonly found in animal and plant foods such as meat, eggs and beans. The protein we eat is broken down into amino acids and used for building muscles, repairing tissues, providing energy and to carry out important body processes. A balanced varied diet gives adequate amounts of protein for our body to function.

Protein intake for highly active people
People who engage in endurance or strength training have greater protein needs than inactive people as the former require more protein for muscle building and tissue repair during training. The table below shows the protein requirements for different levels of activity:

[TABLE=208]
(Source: http://www.sportsdietitians.com.au)

People who exercise intensely tend to eat more and most of their protein requirements can usually be met by a typical diet providing 12% to 15% as protein. For example, an active eighteen-year-old female weighing 60 kg who exercises regularly at moderate to heavy intensity may need an estimated 2500 kcal per day of which 12% to 15% of the total caloric intake should come form protein (300 - 375 kcal). If 1 g of protein produces 4 kcal of energy, it follows that 75 g to 94 g protein has to be consumed per day for adequate nutrition (or 1.25 g - 1.6 g protein/kg body weight/day).

To have a rough estimate of how much protein is in foods, refer to the table of common animal and plant sources of protein below:

    Dietary sources of protein (each serve has 7g protein)

  • 1 whole egg
  • 2 medium-size egg white
  • 30g (one matchbox size) of meat
  • 1 cup milk
  • 3 tablespoon cottage cheese
  • 1 cup cooked beans
  • 1 piece hard tofu (tau kua)
  • 1 small piece (90g) soft tofu
  • 1 packet (500ml) soya bean milk
  • 1/3 cup nuts or seeds

High protein diets for muscle building
People involved in strength and resistance training often increase their intake of protein in the hope of increasing muscle mass, sometimes up to 4 g of protein/kg body weight/day. This can sometimes be unhealthy. Excessive protein intake can increase dehydration, hasten the loss of calcium and worsen existing kidney disease and gout. Protein foods such as meats and full fat milk often contain high amounts of saturated fat, which can increase the risk of heart disease when taken in large amounts. Moreover, excess protein is not stored as muscle but is used for energy. Therefore, current fad diets that advocate high protein low carbohydrate eating are not recommended for people who want to undergo a strength training program.

The latest research in sports nutrition has shown that building muscle mass involves a combination of appropriate training programmes, diet and genetics.

A sensible muscle building regimen will include a diet based on both carbohydrates and protein to provide sufficient calories. A deficit caloric intake will decrease the optimal muscle mass gained. As a general guide, taking three regular meals a day with snacks in between and choosing foods with complex carbohydrates (such as rice, noodles and bread) with moderate serves of protein foods will ensure adequate energy intake for building muscle. Some studies have shown that taking a small snack containing both protein and carbohydrate before and after training may enhance the body's ability to increase muscle mass.

Are protein supplements necessary?
Popular protein supplements for those undergoing weight training include HMB (B-hydroxyl-B-methylbutyrate monohydrate), chromium, colostrum and amino acid supplements. If a person already has a balanced diet with a wide variety of foods from each of the food groups, he or she may not need any protein supplements. These products are not superior to the protein found in food and have not been proven to be consistently effective. Moreover, dietary sources of protein also contain other nutrients, vitamins and minerals. On the other hand, protein powders and liquid meal supplements with balanced amounts of carbohydrates, protein, vitamins and minerals may be beneficial to those who need a convenient way to increase energy intake when training.

The increased protein needs of those undergoing exercise training can easily be met with a healthy balanced diet. Too much of protein may present certain health risks and may affect performance. Therefore, appropriate dietary advice from a sports dietitian or nutritionist to complement an exercise training programme will ensure peak performance and optimal nutrition.