Protein supplements

Protein supplement manufacturers are pushing them hard to many athletes who still consider protein to be the most important nutrient. Protein supplements can be divided into two categories: the first includes whole protein - eggs, milk or soy protein, the second contains individual free amino acids or combinations of them.

• Whole protein

Whole protein supplements are used to increase the total amount of protein in food, sometimes fortified with individual amino acids. Whole protein supplements are not used to meet protein needs, since food contains enough of it. However, these supplements are convenient, especially for athletes with high calorie needs and little time to prepare and eat food. Some supplements are very compact, do not require freezing and are convenient for use on "hot" days. Some of them can be mixed with milk and provide up to half of the protein need, others (protein powders) - with water and are suitable for athletes who are lactose intolerant. Protein tablets or pills usually contain less protein than powders. Instant breakfast mixes are a good alternative to expensive protein powders. Energy bars containing at least 7-14 g of protein (1-2 ounces) help meet protein needs and are convenient to use. Athletes should be aware that some supplements contain excessive amounts of protein per serving (over 50 g) and are not necessary.

• Individual amino acids

Studies have shown that supplements containing small amounts of certain amino acids can improve performance by reducing lactate levels in muscle and blood. Large doses of these supplements do not improve performance. Supplements with certain amino acids are risky because they can cause metabolic imbalances, changes in nerve transmission, and even poisoning.

• Branched chain amino acids

Central Nervous System Fatigue. The branched-chain amino acids (BCAAs) leucine, isoleucine, and valine have been studied in relation to central nervous system fatigue. Exercise-induced fatigue is generally thought to be muscular in origin, but it originates in the brain. One theory is that during prolonged exercise, excess serotonin crosses the blood-brain barrier and causes fatigue; some researchers refer to this condition as overtraining. The amino acid tryptophan is a precursor to serotonin. During exercise, BCAAs from skeletal muscle are oxidized, decreasing their levels and increasing the levels of fatty acids in the blood, displacing tryptophan from its binding site on plasma albumin and increasing the levels in the brain. When the tryptophan to BCAA ratio increases, more serotonin is released into the brain. Altering this ratio by increasing the amount of BCAA or carbohydrates reduces the amount of tryptophan entering the brain. This study supports the idea of using carbohydrates to alter serotonin levels, but does not prove the effectiveness of BCAA in preventing fatigue.

Growth hormone. The amino acids arginine and lysine are believed to increase the synthesis of growth hormone, thereby causing an anabolic effect accompanied by muscle growth.

Glutamine. Although glutamine is not an essential amino acid, some researchers believe that it is needed in high doses during periods of intense exercise. Glutamine is involved in immune responses. Athletes with overtraining syndrome have low plasma glutamine levels, which may impair immune function. Strenuous exercise without adequate recovery depletes glutamine stores, and the body is unable to synthesize glutamine at a sufficient rate to reach pre-exercise levels. Glutamine may also be involved in muscle glycogen synthesis. Adequate glutamine levels may enhance protein synthesis after exercise. Research does not provide convincing evidence to support the use of glutamine supplements.

Two other protein-like supplements worth considering are creatine and beta-hydroxy-beta-methylbutyrate. Both may help increase muscle mass and strength, but whether they are safe for long-term use is unknown.

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