Extra Protein, Extra Performance?
No one can deny the importance of proteins in our diet. They are vital for countless body functions, especially tissue growth and repair. Proteins also provide energy to the body and help ensure a strong immune system. They are large, complex molecules made from amino acids, which in turn, are composed of nitrogen, carbon, hydrogen and oxygen. When proteins are digested, they are degraded into peptides (small chains of amino acids), then into individual amino acids. The liver subsequently deaminates the amino acids, meaning that it removes the nitrogen which is then incorporated into urea, which in turn is secreted by the kidneys.
Many athletes, body builders, or teenage boys who are looking to “bulk up” turn to protein supplements or high protein diets to enhance their performance or accelerate muscle growth. Supposedly, the amino acids arginine and ornithine promote release of growth hormone, a natural hormone that stimulates muscle development. Glutamine and carnitine have also been marketed as strength-enhancing amino acids. By taking large quantities of these proteins, athletes hope to be able to run that extra mile or lift that extra weight without failing their drug tests. But, does it work? More importantly, is it worth the risks?
As a matter of fact, many health experts question the efficiency and safety of ingesting large amounts of proteins. In one study of elite junior weightlifters, consumption of protein supplements including glutamine and carnitine before workout did not result in changes in blood hormone levels during heavy training. Another study with bodybuilders found no change in blood growth hormones after consuming various mixtures of amino acids. Not only that, excess protein intake can have deleterious effects on the body. The recommended dose of protein intake for a normal adult is 0.8 g per kg of body weight per day. That’s 54 g for a person weighing 150 lb. High level athletes (and we are talking about those who compete at the national and international level, not your fifteen year-old who wants to impress a girl) require a bit more than that to compensate for their high energy output. According to one study, athletes competing in power or strength sports need about 1.6 g of protein per kg of body weight, while endurance-trained athletes need about 1.3 g per kg. There is still debate about the exact amount of proteins athletes should consume, but the consensus is that anything over 2.0 g per kg of body weight per day is excessive and no scientific evidence supports beneficial effects above this level. High protein diets on the other hand advocate protein intake on the order of 200 to 400 g a day! Too much protein intake can lead to liver and kidney overload; the liver cannot convert nitrogen into urea fast enough and the kidney has to deal with extra urea. Too much urea results in higher demand for water, which leads to dehydration. And we all know how important it is for athletes to stay hydrated. More serious problems include hyperaminoacidemia (excess amino acid in blood), hyperammonemia (excess ammonia), hyperinsulinemia (excess insulin), calcium loss and overreaction within the immune system.
All you need, really, is a balanced diet and healthy lifestyle. No need to wreak havoc in your body with excessive supplementation. A 3-oz. portion of roast white chicken meat already contains 26g of protein. Beans average about 15g per cup, and pasta contains 5g per cup. While there is evidence that extra protein can be beneficial for athletes, you really don’t need much. A double-blind study with judoists showed that a daily protein supplement of 0.5 g per kg of body weight improved the maximum oxygen uptake. The effects disappeared when judoists stopped taking the supplements. However, such amounts can be obtained from a healthy diet. The body cannot tell the difference between proteins coming from foods and proteins coming from bottles. Proponents of supplements claim that they are more readily absorbed than the protein from food and that certain amino acids increase muscle mass and decrease body fat. The fact is, there is no reason to believe that faster absorption is better; after all, muscles don’t just grow from one second to the next. The best way to gain muscle mass is to add body weight by increasing calorie intake from low fat carbohydrate sources.
Yes, athletes do need more protein, but not in gargantuan amounts. And supplements are great, for those who sell them. There is nothing you cannot obtain from a healthy diet. As for bulking up… exercise by itself already significantly increases growth hormone levels, so leave the health food stores alone and head for the gym!