This series of articles concentrates on Taekwondo, but is applicable to any martial art...

The structure of every cell in your body is partially made up of protein. About 20% of your body’s make-up is from protein. Protein is needed for the growth and formulation of new tissue, for tissue repair and for regulating many metabolic pathways. It is also needed to make almost all the enzymes, hormones and neurotransmitters in your body. It has also a role in maintaining optimal fluid balance in tissues, transporting nutrients in and out of cells, carrying oxygen and regulating blood clotting.

This section will begin by introducing the building blocks of protein, namely amino acids. Then the importance of protein in exercise will be detailed and suggestions on how much protein to consume will be given.

Some health problems associated with excessive protein consumption will be highlighted. Lastly, the benefits of plant-based protein will be painted against the disadvantageous of animal protein.

Amino acids

There are 20 amino acids that are the building blocks of protein. In your body these amino acids are combined in an array of ways to create hundreds of different protein forms. In the digestive system, protein ate, is broken down into smaller molecular units (single amino acids and dipeptides – two amino acids linked together).

Twelve amino acids can be made in your body from other amino acids, carbohydrate and nitrogen. These are called dispensable (DAAs), or non-essential, amino acids. The other eight are indispensable (IAAs) or essential amino acids. IAAs must be supplied in the diet.

The following is a list om IAAs: Isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. Isoleucine, leucine and valine make up one-third of muscle protein and are vital substrate for two DAAs (glutamine and alanine). The body’s requirement is strictly for amino acids, rather than protein.

Exercise and protein

People who participate in regular exercise or sport have a greater protein need than more sedentary people. Additional protein is needed to compensate for increased breakdown of protein during and immediately after exercise, and to assist in repair and growth.

People doing endurance exercise will need to compensate for protein loss due to the body using protein as fuel when muscle glycogen levels have become low. During endurance exercise certain amino acids can be converted into glucose in the liver, to make up for low muscle glycogen. Additional protein is needed for muscle tissue repair and recovery after intense endurance training. Strength and power training stimulates muscle growth and therefore requires extra protein.

A sub-optimal intake of protein will result in slower gains in strength, size and mass or even muscle loss, despite hard training. However, a high protein diet alone will not result in increased strength or muscle size, unless it is combined with heavy strength training. To minimise protein breakdown ensure that your muscle glycogen levels are high. During highintensity exercise lasting longer than an hour, where muscle glycogen levels are low, protein can make up to 15% of your energy needs.

Taekwondo practitioners are both endurance and strength trainers. Depending on your personal focus and training programme adapt your protein needs. Most Taekwondo practitioners that train 2-3 times per week can go with 1.2-1.4 g of protein per every kg body weight. That is about 84-98 g for a person weighing 70 kg. If you train 4-5 times a week for about 1-2 hours 1.4-1.5 g of protein per day for every kg body weight can be considered a reasonable guideline. For a person weighing 70 kg, that would be around 100 g of protein per day.

More than enough

The amount of protein suggested above is far over the RDA. Although too little protein consumption by highly active people can result in loosing muscle mass, protein intake above your optimal requirements will not result in further muscle mass and strength gains. Once your optimal intake has been reached, additional protein is not converted into muscle and will not increase muscle size, strength or stamina.

Protein problems

There are some issues associated with too much protein. Firstly too much protein can cause dehydration, although this can be countered by increasing fluid intake. A high-protein diet cuts endurance. Remember that protein should not be considered your fuel source.

Carbohydrates are the fuel. Excess protein places added burdens on the kidneys, and promote gout. Animal protein is known for ‘hidden’ fat and cholesterol. Fat’s will be discussed in Part 2 of the article. Studies on laboratory animals indicate that high-protein diets shorten the life span. A serious issue with too much protein (especially animal protein) is that it makes the body pH acidic.

The body tries to counter this by using its own stores of alkaline minerals to try and neutralise the acidity. Calcium is leached from the bones and excreted in the urine. Excessive protein consumption is considered one of the biggest culprits making healthy young athletes into sick old people – with arthritis and osteoporosis.

A case for plant-based protein

Contrary to popular belief, a well-planned plant-based diet that excludes meat, poultry and fish can provide sufficient protein for athletes. While plant sources are generally lower in protein and contain smaller amounts of IAAs, this need not be a problem. The key is to eat the right combination of plant-based protein foods each day. Plant-based protein is also loaded with fibre. Conversely, animal protein (as in meat and cheese) has no fibre!

Fibre is crucial for various reasons, but one that has specific impact on athletes is its relation to nutrient absorption. Fibre slows down the rate at which nutrients enter the bloodstream.

This has a stabilizing effect on blood sugar levels. Soluble fibre also affects blood cholesterol levels. Putting it simplistically, during digestion, soluble fibre attaches to fat and pull it out of the body. Soluble fibre is especially plentiful in fruit, beans and oats.

People who don’t eat animal products have: greater longevity; fewer heart attacks and strokes; fewer weight problems; lower cholesterol; lower blood pressure; less diabetes; fewer haemorrhoids, less diverticular disease, and good regularity; less cancer of the breast, prostate, and colon; stronger bones, less osteoporosis; fewer stones of the kidney and gallbladder, and less kidney disease and gouty arthritis. Another problem with animal products is the unhealthy conditions in the animal food industry.

The greatest possible numbers of animals are raised in the smallest possible space at the lowest possible cost.

These animals get hardly any and usually no exercise, which results in up to twice as much fat as the meat from range-fed and free farm animals. Animals ingest and store chemicals in their bodies from the fertilizers and pesticides used on their food. Hormones, antibiotics, and other chemicals are routinely administered to animals, in intensive confinement systems to mask stress and disease and to speed growth. Residues of these contaminants find their way into the food chain. If you insist in using animal products use small amounts.

Egg whites are preferable over the yolk and meats should be kept to skinless fowl, fish fillet and lean beef. Keep to low- or non-fat dairy and refrain from cheese – using it only on special occasions.

Dairy is increasingly being implicated as a main contributor to cholesterol, food allergies and breast cancer. It is also a fallacy that dairy is the best source of calcium. Although milk is high in calcium its relatively high protein content, added to other high protein consumption, actually leaches calcium from the bones as it is being metabolized. Life-style induced calcium losses seem to override any amount of calcium consumed or swallowed. Try replacing your daily use of dairy milk with “milk” made from soy, rice, oatmeal or almond.

Plant-based protein

Plant-based protein seems to have less of the problems associated with animal-based proteins, while retaining all of the benefits. Plant foods are low in fat, high in fibre, free of cholesterol and have adequate protein.

The protein content of many vegetables exceeds 20 percent of total calories. While whole grains average 12 percent, and most legumes average 30 percent. To insure enough amino acids from plant-based foods, choose foods that complement each other. By eating a mixture of protein foods the shortfall of amino acids in one is complemented by higher amounts in the other. Following are categories of plant foods that can be combined for protein complementation:

1. pulses: beans, lentils, peas
2. grains: bread, pasta, rice, oats, breakfast cereals, corn, rye
3. nuts and seeds: peanuts, cashews, almonds, sunflower seeds, sesame seeds, pumpkin seeds
4. quorn and Soya products: soya milk, tofu, soya mince, soya burgers, quorn mince, quorn fillets, quorn sausages.
5. For example, beans on bread or breakfast cereal with nuts can supply you with the right combination of amino acids.

If you are considering a dietary change towards a plant-based diet, make sure that you gain as much knowledge as possible on the topic. Make your change a slow but progressive one. Dietary changes should never be fast and dramatic. Also ensure to substitute suitable foods in place of animal-products. A vegan diet that lacks in quality and variety can be just as unhealthy as an animal-based diet.