Bodybuilders often supplement their diets with a powdered form of protein. The powder is mixed with water, milk or juice. Protein powder is generally consumed immediately before and after exercising, or in place of a meal. Some types of protein are to be taken directly before and after a workout (whey protein), while others are to be taken before going to bed (casein protein). The theory behind this supplementation is that bodybuilders, by virtue of their unique training methods and end-goals, require higher-than-average quantities of protein to support maximal muscle growth.
Currently, no consensus has been reached in determining whether or not an individual in exercise training can benefit from protein and amino acid supplements. Protein supplements come in various forms: ready to drink shakes, bars, bites, oats, gels and powders. Protein powders are available in a variety of flavors.
- Whey protein contains high levels of all the essential amino acids and branched-chain amino acids. It also has the highest content of the amino acid cysteine, which aids in the biosynthesis of glutathione. For bodybuilders whey protein provides amino acids used to aid in muscle recovery. Whey protein is derived from the process of making cheese from milk. There are three types of whey protein: whey concentrate, whey isolate, and whey hydrolysate. Whey concentrate is 29%–89% protein by weight whereas whey isolate is 90%+ protein by weight. Whey hydrolysate is enzymatically predigested and therefore has the shortest rate of digestion of all protein types.
- Casein protein (or milk protein) has glutamine, and casomorphin.
- Soy protein from soybeans contain isoflavones, a type of phytoestrogen.
- Egg-white protein is a lactose- and dairy-free protein.
- Hemp seed contains complete and highly-digestible protein and hemp oil is high in essential fatty acids.
- Rice protein, when made from the whole grain, is a complete protein source that is highly digestible and allergen free. Since rice protein is low in the amino acid lysine, it is often combined with pea protein powder to achieve a superior amino acid profile.
- Pea protein is a hypoallergenic protein with a lighter texture than most other protein powders. Pea protein has an amino acid profile similar to that of soy, but pea protein does not elicit concerns about unknown effects of phytoestrogens. Pea protein is also less allergenic than soy.
Although it is generally undisputed that athletes and bodybuilders need an increased intake of protein, the exact amount is highly individualized and dependent on the type and duration of the exercise as well as the physiological make up of the individual. Age, gender, and body size may vary this protein intake. Some health experts have criticized protein shakes as being unnecessary for most people that consume them, since most users already get enough protein in the normal varied diet with enough calories. However, there is some evidence to support the idea that protein shakes are superior to whole foods with regards to enhancing muscle hypertrophy in the one hour window following intensive exercise. Moreover, for athletes who do not have the time to prepare whole food meals on the run or immediately after exercise, a protein shake may be preferred for practical as well as performance reasons. Additionally, some studies suggest low-calorie dieters, vegetarians, haphazard eaters and those who train very heavily may benefit significantly from protein supplements. Traditional nutrition theory states that the body can only metabolize 5-9 grams of protein per hour, and that excessive daily intake can cause weight gain, kidney problems, osteoporosis, ordiarrhea. However, many bodybuilders report consuming hundreds of grams of protein per day to achieve maximal strength gains, so this nutrition requirement may only apply to the general public. Taking an overdose of protein can lead to a loss of appetite, which may be useful for some dieters. Nutritionists claim that osteoporosis occurs from excessive protein intake because protein can put pressure on the kidneys and lead to bone loss due to calcium leaching. However, recent research has cast doubts on these claims, and suggests that higher calcium excretion may be due to increased calcium absorption in the intestines due to protein intake. Indeed, it is well known that dietary protein is itself important for bone growth, and some studies have found increased bone formation in response to exchanging dietary carbohydrates for protein. Nutritionists also argue against increased protein consumption because weight gain may occur because, as the body cannot store protein, excess protein will either be burned as energy or stored as fat (if you are already getting the calories you need). However, dietary protein is converted to fat far less efficiently than either carbohydrates or lipids, so consuming a calorie excess in protein will result in far less fat gain that would a calorie excess of other macronutrients. Research by Tarnopolsky et al. (1988) showed that for bodybuilding individuals, 1.90g of protein per kg of body weight per day is recommended, whereas endurance athletes require 1.34g/kg/d of protein. Their findings indicated that protein requirements are actually much lower than might be expected and that protein supplements therefore may not be as effective as is popularly believed. However, it should be noted that both of these levels are significantly higher than the levels claimed to be necessary for the general population (0.8 g protein / kg body weight). Studies suggest that there are different protein requirements for anaerobic and aerobic exercise. Endurance athletes in aerobic activity may have increased daily protein intake at 1.2-1.4 g per kg body weight per day where strength training athletes performing anaerobic activity may have increased daily protein intake needs at 1.4-1.8 g per kg body weight so as to enhance muscle protein synthesis or to make up for the loss of amino acid oxidation during exercise.[