19 November 2011
Where's the Protein?
Proteins, which are constructed from amino acid monomers, are considered one of the four major macronutrients needed by the body, along with carbohydrates, lipids, and nucleic acids. Only the first three nutrients listed require delicate balancing. One must consider the sources from which he or she receives those required nutrients. Carbohydrates from fruits, vegetables, and grains; lipids from oily animals such as fish or plant foods like avocados; and proteins from meats, legumes, beans, or possibly dietary supplement powders. Many individuals, vegetarians included, take in additional protein from a supplement powder or pre-made beverage to augment their diets. Protein supplements are quite popular among one group of consumers: athletes. These individuals are typically looking for competitive advantages, increased performance or recovery, or even just a well-balanced diet.
Many questions arise from such goals. Do protein requirements jump that much more for athletes? Does a supplement provide useable protein that builds muscle strength, increases muscular endurance, and/or decreases recovery time? Can over-compensating for protein consumption have any drawbacks? Or are supplements even necessary to create a balanced diet consisting of all 20-plus amino acids? The latter being the main issue: is it necessary to consume a protein supplement in order to receive the benefits from a high protein diet? Many athletes, particularly high school and college athletes, believe this to be the case. This however, may present many health risks—such as impaired renal function and decreased bone mass—and can actually decrease athletic performance thus directly opposing the original goal.
The following sections will look at the effects of protein on athletes' performance and recovery, the possible negative effects on renal function and bone mass, sources of proteins and/or amino acids, and ultimately, what the athlete seeking natural sources of protein should consume whether that is a supplement or a normal diet. Beginning with several experts' studies and findings, the outlying paragraphs will examine possible solutions to those questions, and how young athletes can apply those answers to their own diets. Finally, the question, "can natural proteins found in regular foods have the same effect as a pure protein shake supplement?" will be answered.
In short, despite many claims, advertisements, and testimonials, protein powder supplements do not appear to have any greater effect on the performance, recovery, or health of young athletes than would a balanced diet consisting of natural protein sources.
The arguments in this case are either for the use of protein supplements derived from animal or plant compounds versus the consumption of a purely food, high-protein diet. Many performance athletes choose to bolster their diets with additional post-workout protein powders. The benefits of protein in both performance and recovery are supported by many sources (Driskell and Wolinsky, 2000).
Post-exercise, muscle breakdown and synthesis are much higher (Wolfe, 2000). During that time period, the body uses available amino acids to rebuild its muscle fibers by breaking down large proteins and amino acids, absorbing them into the individual cells, and then building them back up. If one's rate of synthesis were higher than the rate of breakdown, then that would result in an increase in general muscle mass. This would also mean that the individual would require slightly more amino acids to rebuild those muscle fibers. The exact difference can be measured by examining the individual's nitrogen balance. Since every amino acid is constructed with one or more amine functional groups, they contain relatively high amounts of nitrogen. By measuring how much nitrogen enters the body and then how much is lost, nitrogen balance can be determined. A positive balance...
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