by Clare Wood
There are many protein supplements and amino acid products to be found in health food and fitness stores, declaring many benefits including strength and weight gain. While it is true that amino acids are essential for muscle growth and development, taking supplements may not always be required.
What are Amino Acids?
All amino acids are found in the food we eat, in the form of protein. Protein is made up of chains of amino acids strung together, and when eaten they get digested and absorbed into the system as single units called amino acids. Once in the body, these amino acids are used predominantly for building body tissue such as muscle development, though there are other uses for amino acids such as for energy (~5%) and enzymes. Under certain condition there is a greater requirement for protein and amino acids, such as during periods of rapid growth like in teenagers, while undertaking resistance training, and when there is tissue repair such as after an injury or illness.
What are the required daily intake levels of amino acids?
Daily protein requirements for athletes are approximately 1.2 - 1.7g/kg body weight. This means for a person of about 60 kg, their daily protein needs would be between 72 and 102 grams, depending on training and growth. To give you an idea of how much this means in real food terms; 1 cup of wheat based cereal provides 8g of protein, one glass of milk provides 12g of protein, one chicken breast (~150g) provides 42g of protein, 2 cups of steamed rice contains 10g of protein. This adds up to 70 grams of protein already. Include the rest of your daily intake, and you can see how easily it is to meet daily protein requirements. If the amount of weights or resistance training is high, you should be taking in the upper amount of this range of protein intake, which is still easily achievable through a good balanced diet.
Where are amino acids found?
Amino acids or proteins are found in the following foods; lean meats, chicken, fish, legumes (like baked beans) and eggs, and in lesser amounts in dairy foods and cereal products. The animal based protein foods contain a better profile of amino acids, that is, they contain all the essential amino acids for growth and development. If eating vegetarian style, you need to mix and match the non-meat protein foods to get the best profile of these amino acids. For example eating pasta with cheese, or baked beans with toast.
Is it true certain amino acids stimulate growth hormones in teenagers?
Some research on certain amino acids has shown a benefit to weight gain and muscle growth, though there is very little evidence to prove that any amino acid supplement works in these ways. There are three amino acids that have been claimed to increase the release of growth hormone in children and teenagers; they are arginine, lysine, and orthinine. An injection of arginine is used to stimulate growth hormone release in children with a deficiency, working for only a short period of time. However, there is no evidence that an oral dose of these amino acids has the same effect. Supplements with these amino acids contain very low doses. Teenagers will get the greatest benefit out of increasing their total energy intake, which will in turn increase their protein intake to assist with muscle growth.
Amino acid supplementation is not necessary in many athletes as they can get their daily requirements through a well balanced diet. Such a diet would have other benefits such as providing adequate carbohydrates for energy as well as other essential nutrients like B vitamins for energy production, calcium for bone health and other vitamins and minerals. So before you fork out your hard earned dollars on supplements, think about whether you really need them.