Protein powder for losing weight and building muscles
Information, effects, deficiency, dosage, side effects
- What is protein powder?
- Function and effect of protein powder
- Protein powder as a nutritional supplement: A sensible support for a conscious diet?
- Dosage: How much protein powder should be taken?
- Increased protein requirements
- Building muscle with protein powder
- Protein powder to help you lose weight
- Does protein powder stimulate the metabolism?
- Protein powder and digestion: What should you watch out for?
- Protein powder for skin and hair
- Does protein powder strengthen the connective tissue?
- Protein powder as an additional source of protein for the elderly
- Protein powder: Forms and ingredients
- Protein powder: When and how much is best to take?
- Protein powder shakes
- Protein powder overdose
- Possible side effects of protein powder
- Protein powder alternatives
The key advantage of protein powder is that you can quickly and easily consume high quality proteins without cooking. This benefits people who have a very high protein requirement, such as extreme athletes and bodybuilders.
Protein powders are also ideal for older people and those who cannot eat enough food due to an illness and are at risk of losing valuable muscle mass and strength.
What is protein powder?
Protein powders consist of dried and processed proteins of various origins, which can be added to protein shakes when dissolved in liquid. They are offered as dietary foods or as food supplements.
Protein powder is available in different compositions and flavors. They also differ in terms of protein content, amino acid composition and biological value. Most protein powder comes from animal sources. But there are also products available for vegetarians and vegans, which are mainly obtained from rice or soy.
Function and effect of protein powder
In principle, the addition of protein powder in the form of protein shakes has the same effect on the human body as through ingestion through food. However, the advantage of using protein powder is that the type and composition of the proteins you ingest can be better determined.
Proteins are biologically active macro-molecules made up of 21 different proteinogenic amino acids. They are basic building blocks of the human body and fulfil numerous important tasks in the organism:
- The function of cell membranes
- Transport processes within the cell as well as into and out of the cell
- The human immune system
- Building muscle tissue
All of this would not be possible without the interaction of specialised protein classes.
The blueprint for the human proteome - the entirety of our proteins - is given in our DNA, but proteins are subject to constant assembly and disassembly processes. So that they can fulfil their tasks in the body, they have to be regenerated regularly. To do this, it is necessary to add amino acids in the form of protein via food, which are then metabolised and linked again to proteins.
Different proteins can be formed depending on the type of amino acids supplied. The organism itself can produce some amino acids through biochemical conversion processes, others are essential: This means that the body is unable to synthesise them from other building blocks. The essential amino acids must therefore be supplied through food.
Protein powder as a nutritional supplement: A sensible support for a conscious diet?
Ideally, a balanced diet should consist of the recommended amounts of high quality carbohydrates, fats and proteins as well as sufficient vitamins and minerals. However, there are numerous reasons why such a diet is not always possible: For example, stress, illness, competitive sports and psychological stress can make it difficult to get an adequate supply of proteins. The targeted intake of certain nutrients by means of food supplements can also make sense for people who are conscious of their diet.
This is especially the case when a certain goal is to be achieved, such as building muscle mass or losing weight. Especially among athletes and bodybuilders, the consumption of protein powder in the form of shakes is already common practice. A meta-analysis from 2015 examined whether the desired effects can actually be achieved in this way.
The study authors came to the conclusion that the effectiveness of protein powders is directly related to the training intensity of the test subjects: While untrained study participants hardly benefited from the additional protein intake, both trained and untrained study participants seem to have muscle strength and muscle mass during more intensive and longer-lasting training to win.
Dosage: How much protein powder should be taken?
If protein powder is used for training purposes or as a dietary supplement, the recommended reference values for daily protein intake should be observed. The German Nutrition Society (DGE) determines the daily protein requirement of healthy, normal-weight adults at 0.8g per kilogram of body weight. This corresponds to an average protein intake of about 48 to 57g a day.
The amount of protein powder consumed must be added to the amount of protein that is ingested through food. From this total amount, it can be seen whether the protein intake is in the “green zone” or whether there is a deficiency that should be compensated for. Excessive protein intake can also have negative health effects and should therefore be avoided.
It is often recommended by the protein powder producers to take about 30g of the powder per use. Depending on the protein content of the individual products, this corresponds to an intake of up to 28g of protein, which is roughly the recommended daily amount, assuming two to three intakes per day. It makes sense to take larger amounts only if there is a particularly high protein requirement - this is the case, for example, with very intensive physical activity.
However, protein shakes do not replace wholesome meals. If the proportion of protein in the diet is increased for a certain period of time - for example, to make it easier to lose weight - care must still be taken to ensure that there is an adequate supply of other important nutrients. In addition to carbohydrates and fats in smaller quantities, this also includes minerals, vitamins, and fibre.
For a health-wise additional protein intake, it is important to first determine the purpose of the increased protein intake and to align the individually appropriate dose with this. In addition to maintaining muscle mass in old age, protein supplementation is usually used to build muscle mass during sport or lose weight. The following applies to both: Since the body is not able to absorb more proteins than it can utilise, an increased intake should be avoided.
With very intensive training over a longer period of time, the need for proteins can rise up to 1.5 mg / kg body weight. Competitive athletes in the endurance and strength area have a protein requirement of 1.2 to 1.7 g / kg body weight, extreme athletes such as bodybuilders even get up to 2 mg / kg. As a rule of thumb for average sports activity of medium intensity: a protein intake of 0.8 g / kg to 1.0 g / kg body weight is usually sufficient.
The same applies to losing weight: single meals can be easily replaced with protein shakes, and in connection with sufficient exercise, the calories consumed are not put on in fat, but in muscle mass. Here, too, the recommended daily amounts should not be exceeded when dosing, since no additional effect can be achieved.
Increased protein requirements
With a normal, balanced diet, a protein deficiency is rare. Nevertheless, there are situations in which it is difficult to ensure a regular supply of high-quality proteins - examples include diseases with restricted food intake. There are also groups of people who generally have a somewhat higher protein requirement and should therefore pay particular attention to the intake of high-quality protein.
These include older people over 65, growing children, adolescents, and competitive athletes. However, whether it makes sense for these groups of people to supply part of their daily protein requirements with food supplements in the form of protein powder cannot be answered in general, but must always be decided individually.
The popularity of supplemental protein shakes among athletes and in the fitness scene is partly due to the fact that before a training session it is not necessary to ingest large amounts of food that unnecessarily stress the stomach. At the same time, shakes provide enough energy to build muscles. The usability of the available proteins also plays a role.
How proteins are used depends on their biological value. The biological value is a unit of measurement that can be used to determine how efficiently a food protein can be synthesised to form an endogenous protein. The hen's egg was used as a reference value, which for a long time was regarded as the protein source most similar to human proteins.
It is now known that there are proteins that have an even higher biological value than whole egg: the whey proteins. They are therefore particularly suitable for use as a dietary supplement and are often the basis of protein powder preparations. Whey protein also contains a high proportion of the amino acid cysteine, which has a strong antioxidant effect.
In summary, it can be said that supplementing the diet with protein powder at least temporarily offers the advantage that a good overview of the intake of high-quality proteins can be achieved. This can benefit especially seniors who tend to age-related muscle loss. Pregnant women and nursing mothers also have an increased need for protein, but it is not advisable to take high-dose protein powder during pregnancy.
Protein powder and health
An optimal supply of high quality proteins is an important prerequisite for health and resilience. They are the basic building blocks of our body and are involved in many important physiological processes. Adequate intake of proteins with a favourable amino acid profile therefore has a positive effect on health and can prevent deficiency states and diseases.
However, it is not always easy to ingest these particularly high-quality proteins through food. Not enough time for healthy eating, a lot of fast food and premade snacks can do their part to ensure that essential amino acids are insufficiently supplied. But people who try to consciously eat a healthy diet can also develop a protein deficiency under certain circumstances.
This is especially true when choosing a low-protein diet. This includes, for example, the so-called “basic diet”, in which foods such as meat, sausage, and eggs are considered acid-forming and should be avoided. However, these foods contain a lot of protein.
Vegans and vegetarians are also at risk of suffering from a protein deficiency if they do not sufficiently compensate for the lack of protein intake from animal foods. For them, protein powder is available from exclusively plant-based sources.
To ensure an adequate supply of all important amino acids, it is good to know which foods contain essential, semi-essential and non-essential amino acids. The distinction is important in that it makes a statement about which amino acids can and cannot be synthesised by the body from others. Adequate intake of essential amino acids should always be ensured.
Important for health: The essential amino acids
The eight amino acids essential for humans are as follows:
Non-essential amino acids:
- Aspartic acid
- Glutamic acid
High-quality protein powders contain a high proportion of essential amino acids. Like food proteins, they support the building and maintenance of muscles, the functioning immune system and all important metabolic functions.
Non-proteinogenic amino acids, of which there are several hundred in nature, also fulfil important functions in the human body. Some of them, such as carnitine, are valued by athletes for their effects on fat burning and muscle regeneration. Carnitine is therefore added to many protein powder products. However, the study on the effects of these compounds is not entirely clear.
Building muscle with protein powder
Proteins are the main components of our muscles. Muscle mass and muscle strength are essentially dependent on a favourable energy and protein utilisation. If we do not consume enough protein, all training efforts are in vain: successful muscle building is not possible with a lot of effort.
Even with a good supply of protein, there are some criteria from a sports science point of view that should be observed for a targeted muscle building. In addition to the amount of protein ingested, this also includes the time of ingestion and the type of protein that is to be added. If the protein is supplied via protein powder, the type and number of additives used is also important.
Many athletes therefore try to specifically effect the composition and amount of the proteins they consume. For a long time, the opinion among sports scientists was that optimal protein intake should always be shortly after training - within the so-called "anabolic window". This assumption is now outdated in this form.
In a meta-analysis from 2013, which included studies with more than 1000 participants, the authors involved concluded that taking shortly after the training accelerated protein storage in the muscle. However, the most effective protein formation should not take place until six to eight hours after training - some sports scientists therefore recommend taking protein preparations in smaller doses every two hours after training.
For a targeted muscle building, strength training in combination with proteins that have a high biological value is best suited. In our natural diet, proteins with a high biological value are mainly found in beef, for vegetarians a mixture of egg and potatoes is a good substitute. Skimmed milk and whey are also good sources of protein after training: the particularly high-quality whey protein is not without reason considered to be the frontrunner in the field of nutrition products.
Protein powder to help you lose weight
In addition to willpower and patience, healthy weight loss requires above all the right mix of nutrients and sufficient exercise. Unilateral diets that lure in the hope of rapid weight loss, on the other hand, usually do not keep their promises and, in extreme cases, can even result in health damage.
Many of these diets are short-term trends that want to give the impression of being a completely new and revolutionary way of eating. Many promise that the pounds should drop without much effort. As different as the approaches of these diets may be, they all promote one-sided dietary rules, which have deficiency symptoms preprogrammed.
In many diets, the desired effect of rapid weight loss is often achieved through the loss of fluid and muscle mass - in principle the opposite of the desired diet success. Some of these 'blitz diets' also advocate avoiding fat and carbohydrates as much as possible and providing a large part of the daily food intake with proteins.
In principle, there is nothing wrong with a higher protein content of the diet as part of a diet, provided that vitamins and minerals as well as a minimum proportion of fats and carbohydrates are added. This increased protein percentage proves to be particularly useful if strength training is on the program and the muscle percentage of the body is to be increased.
What role can protein powders play in losing weight? Protein powders are often recommended in diet forums and weight loss guides to stimulate the metabolism. However, there is no scientific evidence for this alleged effect. However, several studies provide evidence of positive effects such as building muscle mass and reducing body fat with protein supplementation and at the same time reducing calories.
The most favourable effect profile seems to have whey protein, regardless of what type of diet is followed while ingested - the weight loss success was highest in this group of study participants. It can be concluded that a sensible change in eating habits, combined with an increased intake of high-quality proteins and regular exercise, is a sensible way of targeted weight loss.
A positive side effect of protein supplementation during a diet should also not be underestimated: proteins have a strong satiating effect, even if they are taken in the form of a drink - as a protein shake. This has a positive effect on the motivation of those willing to diet, because nothing is worse than trying to lose weight while constantly feeling hungry.
Does protein powder stimulate the metabolism?
One of the many tasks that proteins perform in the body is their function as enzymes. These regulate and accelerate the metabolic processes in the body through catalysis. The metabolism describes the entirety of the biochemical and physical processes that take place in the body. These include:
- foreign substance metabolism (intake of foreign substances)
- the building material change (build-up and breakdown of the body substance)
- the energy metabolism
Another classification is the metabolic process. A distinction is made between anabolic and catabolic metabolisms. The catabolic metabolism is the one in which complex substances from food are broken down into their basic components and energy is thereby obtained. In anabolic metabolism, on the other hand, the substances required by the body are built up using energy from the particles formed in the catabolic metabolism.
The total metabolism of our body runs on many different metabolic pathways. These are extremely complex, interlinked and mutually influencing biochemical reactions. These are only partially reversible in individual steps - the entire metabolic pathway always leads to an irreversible end product.
Different chemical reaction types occur in the individual metabolic pathways. Proteins play a very important role here - in addition to the enzymatically catalysed reactions already mentioned, they are primarily used as transport proteins in the cell membrane.
Very few molecules can pass through the cell membrane unhindered. All others need so-called active or passive transports. These function via different structures in the cell membrane or pass through the cell membrane through specific proteins: The cell metabolism is therefore also protein-dependent.
You cannot speak of a direct “metabolic stimulation” by protein powder - at least there is no clear scientific evidence for this. Proteins from shakes and protein powders, like food proteins, naturally fulfil their natural functions in human metabolism. The advantage of protein powders is that they have better control over the type and exact amount of the added proteins.
Protein powder and digestion: What should you watch out for?
A very high protein diet can favor digestive problems such as constipation, gas and abdominal pain. Of course, this also applies if too much protein is absorbed by protein powder. However, it helps to acquire some facts about the digestion of proteins and to adjust your food intake to avoid possible unpleasant effects.
In order to be able to digest proteins, they must first be broken down into their basic structures, so-called polypeptides, in the stomach. This happens with the help of stomach acid. The protease pepsin, a protein-decomposing enzyme, then divides the polypeptide chains into individual polypeptides.
After further transport into the small intestine, further proteases split into the smallest subunits, the amino acids. These are then absorbed by the intestinal mucosal cells and transported into the bloodstream, from where they reach their destination.
The breakdown of amino acids creates ammonia, which is metabolised in the liver. The urea that is produced in the end is excreted through the kidneys. One reason why you should not overdo it with protein intake: Large amounts of urea contribute to the formation of kidney stones.
When protein is digested, the gaseous nitrogen also forms as a by-product. As a result, the intestinal tract can become distended and uncomfortable flatulence can arise. Another possible cause for such complaints can also be a food intolerance.
If a high protein intake causes the symptoms described, the cause should be determined first. In the case of a food intolerance, it makes sense to replace the responsible protein source with another one. This may be tolerated better. The most common protein intolerances concern products that are made from egg or milk. These can often be easily replaced with rice or soy proteins that cause fewer allergies.
A high-fibre diet also helps compensate for digestive problems such as bloating and constipation caused by an excess protein intake. Dietary fibre is mainly found in fruits, vegetables, and whole grains. They bind water and thereby increase the viscosity of the stool. About 30g of dietary fibre should be consumed daily.
Unilateral diets with a high protein content can also lead to a change in the natural intestinal flora. Good results can be achieved by changing the diet and / or by taking probiotics that restore the balance of the bacterial colonisation in the intestine.
Protein powder for skin and hair
An important function of proteins in the body is also the shaping and stabilisation of cells and tissues. These protein molecules are also known as structural proteins: they often show a fibrous structure and are of great importance to the human body, especially for the skin, hair, and nails.
The structural proteins keratin, collagen, and elastin are particularly important. Together with other macromolecules in the intercellular space - e.g. between the individual cells - they form the so-called extracellular matrix. Like all other proteins, these structural proteins are built up from amino acids.
Collagen and elastin play a very important role in the stability and elasticity of the skin, while keratin ensures the structure and resilience of the hair. There is also a special functional connection between elastin and collagen: while collagen provides tensile strength, elastin has a rubber-like consistency and is extremely stretchy. This gives ligaments, for example, great tensile strength with simultaneous elasticity.
The interaction of collagen and elastin has an important function in the skin in particular: strength and elasticity depend essentially on these two structural proteins. The metabolism of these two shaping molecules decreases with increasing age and the epidermis slackens. To prevent this, a sufficient intake of collagen and elastinogenic amino acids is important.
Keratin plays a crucial role in strong, healthy hair. It also occurs in the epidermis and nails, is almost insoluble in water and extremely resistant. It owes these special mechanical properties to its structure, which consists of α-helices cross-linked via disulphide bridges. The structural amino acid is cysteine. Protein powders taken to strengthen hair and nails should therefore have the highest possible share of cysteine.
Does protein powder strengthen the connective tissue?
Collagen is one of the most common proteins in the body, it makes up about a quarter of the total amount of the body's own proteins. Its structure consists of three molecules in the form of a triple helix of up to several thousand amino acids depending on the type of collagen. This structure defines its shape as a long, tear-resistant fiber.
Collagenic amino acids are primarily proline and glycine as well as some hydroxylated amino acids that are used for cross-linking. This way, a very stable collagen matrix is created which forms the connective tissue in the human organism when aggregated into collagen fibrils. Collagen-forming protein powders are said to support the natural functions of the connective tissue in the body.
Glycine and proline are not essential amino acids, they can be metabolised in the body from other amino acids and other substances - e.g. glycine from serine, proline from glutamic acid, and ornithine. Both amino acids are found in most food proteins. So it is not absolutely necessary to pay attention to the content of these amino acids when taking protein shakes.
Protein powder as an additional source of protein for the elderly
Older people generally have a slightly higher protein requirement. However, there are no clear recommendations as to which amounts should be added daily. Even the German Nutrition Society states that the reference values it publishes are estimates because the protein requirements for older adults cannot be determined with sufficient accuracy. The estimated minimum amount for people aged 65 and over is around 1 g per kilogram of body weight.
Older people often suffer from malnutrition. This is particularly true for hospital patients over 75 years of age who, due to multi-morbidity, consume less food than would be necessary for a good supply of nutrients. An insufficient protein supply affects the functionality of the muscles and can lead to an increased risk of falling for this age group.
A randomised, placebo-controlled, double-blind study from 2012 examined in more detail whether additional protein supply via dietary supplements is beneficial for frail older people. It turned out that the supplemental protein intake did not lead to a change in the muscle mass of the test subjects, but it did indeed lead to a significant improvement in muscle strength.
However, it cannot be concluded whether it makes sense in general to replace a possibly existing protein deficiency with protein preparations in old age. The decision for or against supplementation should always be made in individual cases and if possible with medical advice. Two advantages that protein powder can offer for older patients are the simple preparation and the possible use as a drinking solution.
Protein powder: Forms and ingredients
Protein powders are available in many different compositions and flavours and have found a strong following not only in professional sports and body building, but also in the fitness and health scene. Their undeniable advantage is that they can deliver the desired amount of protein, which is so important during training, quickly and without complicated preparation.
Protein sources for shakes and powder are naturally occurring food proteins, mainly whey, milk, and egg. Since the demand for animal product-free alternatives for the shaker has increased significantly in recent years, most suppliers now also have vegan protein powder available. Vegan protein powders are usually made from soy or rice.
Whey protein powder (whey protein)
Whey is the English term and whey protein is probably the best known and most popular of the protein supplements available on the market. The advantage of whey protein is its biological value, which is higher than all other known food proteins. This means that it is converted into the body's own protein very efficiently. In addition to casein, whey is a component of milk, which contains all essential amino acids. Their proteins are α- and β-lactoglobulin, immunoglobulins, proteose peptone and serum albumin. Whey protein is considered effective for building muscle under training conditions.
Milk protein powder
Casein or milk protein powder is the second part of milk proteins. It has a protein content of approx. 80% and a lower biological value than whey protein. Milk protein is not suitable for people with a lactose intolerance: it contains a large amount of milk sugar, which cannot be digested if you are lactose intolerant and, in addition to diarrhoea, can lead to a variety of other health problems.
Egg protein powder
Egg protein is the name giver for all other types of protein. Egg protein powder is therefore obtained from the egg white of chicken eggs. It had a biological value of 100 and thus originally the reference value for this unit of measurement until the even more efficient usability of the whey protein was discovered. Egg protein powder has also been shown to have a positive effect on the muscle strength during strength training.
Soy protein powder
Soy-based protein powder is a good alternative to protein products from animal sources, especially for vegetarians and vegans. It offers health benefits over other protein powders because, unlike these, it contains no cholesterol. Soy protein is also well tolerated in the case of a lactose intolerance, since it contains no milk sugar.
Rice protein powder
Rice protein is the second vegan alternative to animal protein products. It is obtained in a complex process by means of fermentation from unpeeled whole grain rice. The rice is first germinated, which greatly increases its vitamins and trace elements content.
The rice protein obtained is then fermented with plant enzymes. With high-quality products, this is done gently and without exposure to heat, since heat severely damages the structure of the proteins.
Rice protein is an alternative for certain allergies: it is well suited for people with milk, egg and soy allergies. However, caution is advised for pollen allergy sufferers and people who have certain food allergies: many of them are also allergic to rice proteins.
Collagen protein powder
Collagen protein powder is rather an exceptional product, most protein powders do not contain collagenic amino acids. On the other hand, these are more often found in protein bars. Collagen protein products can be recognised by the two ingredients hydroxyproline and hydroxylysine - e.g. by the hydroxylated forms of the two amino acids proline and lysine. Collagen protein powder is made from gelatine, which is why it is not suitable for vegetarians and vegans.
Multi-component protein powder
Multi-component protein powders are mixtures of two or more different protein powders, to which additives are often added. An example of this is carnitine, an ammonia compound essential for the cell's energy metabolism. Carnitine can be eaten by meat eaters, but it does not occur in plant nutrients.
However, this is not a cause of concern for vegans and vegetarians, since carnitine can be synthesised by the body itself from the amino acids lysine and methionine. For this, it needs vitamin C, vitamin B6, niacin, and iron as co-factors.
Protein powder: When and how much is best to take?
Unfortunately, there is no recommendation that can be considered as generally applicable. The amount that is individually required to maintain or increase muscle mass depends not only on age and gender, but also on the physical activity that is essential for building muscle. A single dose of around 30 mg, best consumed on multiple intakes shortly after training and in the following hours, is most commonly recommended by nutritionists.
The ideal form and amount of protein powder to be taken also depends on the type of training: People who train in the high performance range and want to achieve an anabolic effect, need more protein than endurance and recreational athletes. However, the individual dose should not exceed sports and nutritional medical recommendations in order to avoid undesirable side effects.
Protein powder shakes
Protein shakes are probably the most popular form of protein supplementation. They can be prepared quickly and easily in a shaker, are available in different flavours, have a long shelf life in powder form and are easy to store. Above all, they offer the opportunity to have a snack without unwanted fat and with low calorie intake.
Shakes have another advantage, especially when it comes to sports: They also replace part of the loss of fluid with sweating, which can be considerable when exercising intensively.
Protein powder overdose
Too much protein is normally not a health hazard. However, it is not expedient to supply the body with such large amounts of proteins that it cannot metabolise them sensibly. An excessive protein intake can lead to undesirable effects such as diarrhoea or bloating, even in healthy people.
These are related to the metabolism of the proteins: If too much protein is available, the body does not metabolise it to muscle mass but to carbohydrates and ultimately to fat. This usually achieves exactly the opposite of the desired effect: Very few consumers of protein preparations want to gain weight instead of optimal muscle building.
Care should be taken with existing diseases, particularly the kidney. In the protein metabolism, ammonia is created as a breakdown product, which is converted into urea and excreted via the kidney. A very high protein consumption puts a strain on the kidney, because the amount of urea can no longer be filtered from the blood.
Possible side effects of protein powder
Side effects that can occur due to the consumption of protein powder usually have two causes: an overdose as described above or an intolerance or allergy.
Allergies to certain proteins are common and can usually be detected by an allergy test. The proteins you are allergic to must then be avoided. It is more difficult with food intolerances, which are not so easy to detect.
The most common is lactose intolerance, which makes digestion of milk sugar difficult due to an enzyme defect. In the case of lactose intolerance, proteins from milk or dairy products should therefore be avoided. Soy products also have a high intolerance potential.
However, intolerances do not have to be directly related to the protein that a protein powder contains, but can also be directed against an additive. These are often products that contain components of cereals containing gluten, such as glucose syrup or maltodextrin on a wheat or barley basis.
Protein powder alternatives
A good alternative to protein powders is a protein-rich diet. Right before and after exercise, it is not always possible to eat a protein-containing meal. Since a full stomach is not a good starting point for intensive sporting activities, this is particularly out of the question for competitive and strength athletes.
A natural alternative is offered by a glass of milk or fermented milk, which contains a high proportion of milk and whey proteins and additionally add to a fluid intake. However, the taste of milk is not everyone's cup of tea, and high amounts of drinking milk before training can also be a nuisance.
Protein bars offer a good alternative here: They hardly burden the stomach, are available in many different flavours and contain a high proportion of the desired proteins even in small quantities.