Throughout the history of fitness, bodybuilding, and strength sports in general, the views of athletes and scientists on how much protein is needed for gaining and maintaining muscle mass have changed dramatically.
Strength athletes in Ancient Greece believed that the secret to their strength was red meat, and they consumed it in excess, while some modern scientists question not only the existence of a link between strength performance and the consumption of animal protein but also the necessity for athletes to consume it in higher doses compared to physically inactive individuals.
This article will explore what scientific research says about how much protein is needed per day for gaining and maintaining muscle mass (for men, women, and older adults).
Key points:
The Importance of Protein. Common Mistakes in Protein Consumption
Protein in food and the proteins in our body (for example, muscle protein) are made up of amino acids. They are often compared to building blocks.
When we consume a natural protein product or drink a protein shake, during digestion it is broken down to the level of amino acids, which are transported to various parts of the body, where they are “reassembled” into different protein structures.
There are a huge number of types of proteins in the body, which perform a similarly vast array of functions, ranging from the division and repair of DNA cells that carry genetic information to the creation of hormones and tissues such as hair, nails, muscles, and more.
For the synthesis of muscle protein, from which muscles are made, a variety of amino acids are required, some of which can only be obtained from food. These are called essential amino acids.
With a deficiency of protein in the diet, the processes of muscle cell recovery are disrupted, which means that muscle mass growth slows down or becomes impossible (proportional to the degree of protein deficiency and the duration for which it is observed). Moreover, the risk of developing various diseases, including chronic ones, increases.
Even if a person does not train, there is always a basic need for protein, as every day the body’s cells are renewed, die, and new ones are created, and for this, amino acids are needed.
In a physical training regime, the need for protein significantly increases, as amino acids are necessary for the recovery of damaged muscle cells and for ensuring their growth. That is why for gaining muscle mass in bodybuilding, the daily protein intake is higher.
But fats and carbohydrates are also very important, as they provide energy for workouts: if they are low, some of the protein will be used for energy, reducing its effectiveness as a building material. See Proper Nutrition for Gaining Muscle Mass.
A lack of protein in the diet makes it impossible to recover muscle cells and grow muscle mass
Despite its importance, the above does not imply that protein is beneficial in any quantity, and the more, the better.
Excess protein in the diet, according to scientific data, increases the risk of developing serious diseases, including cancer, kidney stones, bone demineralization, liver and kidney dysfunction, and more.
Among scientists, there are very staunch opponents of consuming protein in doses exceeding even 1 g/kg of body weight. One of them is Colin Campbell, the author of the notorious “China Study” on the harm of protein as one of the factors in cancer development, an interview with whom can be read here.
Colin Campbell points to the dangers of excessive consumption of all types of proteins with high biological value – the most popular in bodybuilding – in terms of the onset and development of cancer.
Excess protein in the diet can increase the risk of developing serious diseases, including cancer, decreased bone density, and kidney stones.
Daily Protein Norm: A Subjective Method. Learn to Listen to Your Body
If you ask the question “How much protein should I consume daily?” to different athletes and various experts (nutritionists, doctors, and scientists), you will receive a mix of numbers that differ significantly.
Among athletes “over 100 kg,” advice of 3-4 g per kilogram of body weight is often encountered… the more, the better… 400 g a day…
At my weight of 90 kg, 4 grams of protein is equivalent to 1.3 kg of chicken or ~2.4 kg of cottage cheese. That is an incredible amount.
Many are convinced that such an amount is necessary to overcome a plateau and initiate the process of muscle mass gain. But what are their beliefs based on?
In my life, I have conducted numerous experiments. With extremely high protein intake (around the indicated figure of 4 g per kg) and extremely low (less than 1 g per kilogram). And with plant protein and animal protein (dairy, eggs; I haven’t eaten meat for a long time).
When protein is very low: muscle soreness the day after a workout, slow recovery, persistent minor muscle injuries, lethargy, lack of motivation, frequent colds…
Nausea, lack of appetite, digestive issues such as constipation and heaviness in the stomach, obsessive thoughts about needing to… consume a certain amount of protein every day, not to mention characteristic health problems – are signs that there is too much protein.
We are structured in such a way that an excess or deficiency of any substance in the diet usually manifests itself in one way or another. The essence of the subjective approach in determining the individual daily protein norm is to define it by listening to and observing the body’s reaction to a certain amount of it.
As a starting point, you can choose absolutely any dosage. However, it is more advisable to use the one recommended below based on scientific research.
After that, take protein in the calculated amount based on the dosage for several months, for example, two to three, and observe the body’s reaction. If there is no progress in muscle mass growth or clearly manifested symptoms of protein deficiency in the diet, the dosage should be increased and observed again.
Conversely, if the symptoms indicate an excess of protein, you simply feel that “it’s not working,” or you have medical conditions characteristic of protein excess that have manifested or have been observed for a long time, then the dosage should be reduced.
Learn to listen to your body: both a deficiency and an excess of protein manifest themselves through unpleasant sensations and health problems.
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How much protein should you drink per day? Scientific research
The evolution of scientists’ views on the importance of protein in sports
In the mid-19th century, it was believed that protein was the main source of energy for muscle contraction (specifically energy!), which is why athletes of that time consumed it in very large quantities, primarily in the form of various types of meat.
Later, in the late 19th to early 20th century, it was shown that the role of protein as an energy source for muscles is very insignificant (only about 10% is used for these purposes), and scientists’ views on its importance for athletes changed to the opposite: it was believed that sports do not increase a person’s need for protein, and that the amount obtained from food in a normal diet is sufficient.
During this time, scientists’ attention shifted from protein to carbohydrates and fats as energy substrates, and the importance of protein was ignored.
In the 1970s, data emerged confirming that increased protein intake above the norm can be beneficial for athletes.
However, even today there is no consensus among scientists on the question of “how much protein is needed per day for athletes”.
The existing official recommendations regarding daily protein needs are based on studies involving ordinary people, not athletes, and many of them have not been updated in accordance with the results of the latest research, including studies involving athletes, which are becoming more and more numerous.
As for the athletes themselves, the overwhelming majority of them, especially in strength sports and bodybuilding, consume protein in amounts exceeding the generally accepted recommendations by 300-775%.
The recommendations of scientists regarding the daily protein norm for athletes have radically changed throughout history. Even today, there is no unified position on this issue among them.
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Athletes do have a higher protein requirement
Today, experiments on humans and animals have clearly shown that during training, especially prolonged ones, muscle cells are damaged and nitrogen levels in urine increase 13.
Nitrogen is a structural component of every protein molecule, including muscle proteins, from which muscles are built. Its presence in urine (nitrogen balance) is an indirect indicator that can be used to assess the sufficiency or, conversely, deficiency of protein in the diet.
Additionally, physical activity significantly increases the need for BCAA amino acids 14, known for their important role in the processes of gaining and maintaining muscle mass.
Importantly, the need for these amino acids is inversely proportional to the amount of stored glycogen in the muscles.
Glycogen is the “storage of carbohydrates” or energy in the muscles and liver. On low-carbohydrate diets, which are among the most effective for weight loss and popular for cutting in bodybuilding, glycogen stores are significantly depleted.
BCAA amino acids can be used by muscles for energy, so during cutting, it is recommended to increase their amount in the diet. See How to take BCAA amino acids and… is it worth it? Maybe protein is better?
The reverse is also true: adequate carbohydrate intake, especially before training, is an effective way to preserve BCAAs from being “burned” for energy and to make their use for muscle cell recovery and growth more effective 13.
For athletes for whom endurance is important (runners, cyclists), the protein requirement is no lower than for those for whom strength performance matters.
In several experiments, it was shown that when professional runners consumed 0.9 g of protein per kg of body weight, their nitrogen balance was negative, indicating a protein deficiency; increasing the dose to 1.5 g/kg normalized the nitrogen balance 15.
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The daily protein norm for men is higher than for women. This is explained by the lower muscle mass in women, smaller glycogen stores, and better utilization of fats for energy, due to hormonal mechanism differences 16.
For strength athletes, including bodybuilders, the protein requirement is even higher than for endurance athletes 17.
Scientific research confirms the increased protein requirement for athletes in both strength sports and endurance training. The daily protein norm for male athletes is higher than for females.
Daily protein norm for athletes (men)
The Institute of Medicine of the USA 1 provides the following recommendations: 10-35% of total daily caloric intake should come from protein, putting us in the position of having to solve complex mathematical problems to calculate total caloric intake and the percentage of it, followed by conversion into grams and real products.
It’s inconvenient.
Moreover, the range in this recommendation is confusing: 10-35% is quite a broad range, and, in fact, if we simply leave everything as it is, our usual diet will likely meet the specified daily protein norm… sometimes more, sometimes less.
There is also another problem.
If the total caloric intake is very low – a common reason for the lack of progress in gaining mass in bodybuilding – even the upper limit of protein intake (35%) may be insufficient, as in this case, protein will serve an energy function instead of a structural one.
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Researchers at McMaster University 2 assess the daily protein requirement for athletes sufficient for maximum stimulation of muscle protein synthesis in other more understandable units: 1.3 – 1.8 grams per kilogram of body weight.
However, scientists note that “a higher amount of protein may be necessary for an athlete in the case of frequent and intense training, as well as during calorie restriction for weight loss“.
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A similar result is found in a large study from The University of Western Ontario 3:
“The daily protein requirement for physically active individuals exceeds the norm for ordinary people by at least 100% (1.6 – 1.8 g/kg compared to 0.8 g/kg). The actual doses of protein that athletes take in practice are even higher.”
Among the factors under which the recommended norm for athletes may be adjusted upwards, the authors mention:
- low overall calorie intake (during “cutting” phases, for example)
- low-carbohydrate diets (considered one of the most effective for weight loss);
- high training intensity or duration;
- type and quality of proteins used;
- level of training;
- meal frequency, etc.
In one experiment, significantly greater effectiveness in mass gain was shown in bodybuilders when consuming protein at a rate of 3.3 g/kg compared to 1.3 g/kg of body weight 18.
This study deserves special attention because it confirms the widespread belief in bodybuilding that extremely high doses of protein combined with the stimulus of strength training can promote muscle mass growth 18.
However, in this study, a higher rate of amino acid oxidation was observed (150% higher).
What does this mean? It means that a significant portion of them was used for energy rather than for building muscle tissue, indicating a likely excessive level of protein in the diet.
In another experiment, scientists showed an increase in muscle synthesis in strength athletes when changing the protein dose from 0.9 to 1.4 g/kg, but further increasing the dose to 2.4 g/kg had no effect 19.
In people who do not engage in sports and lead a sedentary lifestyle, amino acid oxidation processes are observed at doses starting from 1.4 g/kg of protein, while in strength athletes – at 2.4 g/kg and above.
When protein is consumed by ordinary people at doses above 1.4 g/kg and by athletes above 2.4 g/kg, it is used in the body inefficiently, increasing the risk of harm to health.
– What will happen if a non-athlete consumes as much protein as an athlete?
This question is particularly relevant in light of scientific data on the benefits of protein for weight loss – a fact that underlies many modern diets, in particular, the Dukan diet and Atkins.
Consuming large doses of protein over a long period is likely to increase the risk of side effects of protein.
The authors of the sports nutrition encyclopedia Nutrition in Sport conclude that the optimal daily protein dose for strength athletes and bodybuilders is 1.4-1.8 grams per kilogram of body weight (175-225% higher than current recommendations for ordinary people).
It is also important to note that these values are obtained from studies of natural athletes who do not use anabolic pharmacological agents. When using the latter, the daily protein norm is even higher, as they increase the rate of muscle synthesis 20.
Daily Protein Norm During Body Cutting
In bodybuilding, professional athletes and amateurs follow the following rule to determine the amount of protein:
- 1.8-2.2 g of protein per kilogram of body weight per day;
- 2.6 – 3.3 g of protein per kilogram of body weight during “cutting” or any other calorie-restricted diet.
These figures are supported by research.
Researchers from AUT University 4 based on an analysis of available scientific studies (up to 2013) draw the following conclusion:
“The daily protein norm in bodybuilding during calorie restriction while cutting body weight is 2.3-3.1 g/kg of body weight and may be further increased depending on the degree of calorie restriction and body fat percentage.”
At lower values, there is a high likelihood of muscle catabolism (breakdown).
The experience of well-known representatives of professional bodybuilding (Arnold Schwarzenegger, Evan Centopani, Phil Heath) confirms these values. Arnold Schwarzenegger consumed about 2.2 g/kg.
Scientific research indicates that the optimal amount for muscle mass gain is 1.4 – 1.8 grams of protein per kilogram of body weight.
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Protein Norm for Elderly People Engaging in Sports
Campbell studied how different doses of protein (0.8 or 1.6 g/kg) affect nitrogen balance in elderly individuals (56-80 years old) who participated in a strength training program for 12 weeks 21.
A negative nitrogen balance, muscle cell breakdown, and decreased bone mineralization were found in the group that consumed 0.8 g/kg, indicating insufficient protein intake in the diet.
In contrast, participants (both men and women) on a high-protein diet showed a higher rate of muscle synthesis, increased muscle mass, and improved bone mineralization.
Interestingly, the data on the daily protein norm for elderly people engaging in sports aligns with that for young athletes.
This is particularly important in light of the increasing number of elderly individuals involved in various fitness programs each year: doctors recommend that they maintain a level of physical activity to preserve muscle mass and bone health.
For physically active elderly individuals (> 50 years old), the daily protein norm is as high as for young people.
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Daily Protein Dose for Female Athletes
The values mentioned above for the daily protein norm apply to men.
There is very little research on female athletes.
The available data suggests that the protein norm for women is lower than for men. However, there is insufficient basis for definitive statements, and scientific data on women engaged in bodybuilding is virtually nonexistent.
Currently, it is believed that for women, protein intake of more than 1.3 g/kg per day provides advantages in strength sports 22.
Research does not confirm that protein intake at dosages exceeding 2.6 g/kg further increases the effectiveness of muscle mass gain.
There is very little scientific research on how much protein is needed per day for women engaged in sports and bodybuilding, in particular. It is believed that a daily norm of 1.3 g/kg provides advantages for muscle mass gain.
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The type of protein affects how much you need to consume per day
Not all types of protein are the same. They differ in the speed and degree of absorption, as well as the quality of the amino acid profile.
In the material The Best Natural Protein from a Scientific Perspective, we evaluate different types of proteins from a scientific standpoint.
The most popular protein in bodybuilding is whey protein, which is mainly explained by its high digestion speed and absorption rate: it is close to 90%, meaning that out of 100 g, ~90 g is actually utilized by the body.
It is also very rich in essential amino acids, especially leucine, which is one of the most anabolic, i.e., important for muscle growth, and is part of BCAA amino acids 5.
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Egg protein is digested more slowly than whey protein, but its absorption rate is equally high. Its amino acid profile is also complete 5.
Plant proteins are inferior to animal proteins in quality: their amino acid profile is generally incomplete (one or more essential amino acids are missing or present in insufficient amounts), and the absorption rate is significantly lower 5.
A low absorption rate means that to meet the daily requirement for plant protein, more will be needed.
The issue of protein inadequacy can be addressed by combining different types (see the material Vegetarianism and Sports: Benefits and RISKS).
Vegetarians are recommended to increase the above-mentioned protein intake recommendations by 20-30% when calculating their daily protein norm.
To be fair, it should be noted that there are studies indicating that the type of protein used for athlete nutrition does not have particular significance 23.
We recommend: Vegetarianism and Bodybuilding: How to Gain Muscle Mass.
When calculating how much protein is needed per day, it is important to consider the type of protein: plant and animal proteins have different rates and degrees of absorption, as well as amino acid compositions, so it is recommended to increase the daily norm of plant proteins beyond the recommended amount.
When Should You Drink Protein? Some Recommendations
Finally, for a complete picture, let’s touch on the question of when to drink protein, which is discussed in detail in the material How to Properly Take Protein for Muscle Growth?.
Frequency of Protein Intake
There are various opinions on this matter.
A common rule in bodybuilding is to eat small portions 5-6 times a day, which helps avoid overloading the digestive system and speeds up digestion.
However, some scientific studies suggest that the frequency of protein intake does not have particular significance. The main thing is to meet the daily protein requirement throughout the day 6.
Interestingly, a state of hunger is somewhat beneficial for muscle growth, as it stimulates the release of growth hormone. We discussed this in the material on the benefits of intermittent fasting.
Protein Before and After Training
Taking protein before and after training likely has significance for muscle mass gain.
Why ‘likely’? Because the research results are contradictory.
Some of them indicate that protein intake before and after workouts helps in gaining muscle mass 7, 8, 9, while other studies suggest that there is no correlation 10, 11.
The importance of protein intake after workouts is emphasized by Arnold Schwarzenegger.
Protein before sleep
Taking protein before sleep also has scientific backing 12, as during sleep the body and muscles actively recover, and for this, protein is needed, specifically “slow” protein that will be digested slowly, providing a gradual supply of amino acids.
Sources of such protein can be cottage cheese or sports casein. Some facts indicate the harm of sports casein.
The frequency of protein intake is not particularly important. It is recommended to take protein before sleep and after workouts.
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Conclusion
The question of the necessary amount of protein per day for muscle gain is very relative. The answer to it is determined by many factors, including gender, level of physical activity (intensity, frequency), type of sport, age, dietary restrictions (vegetarianism, veganism), etc.
Based on available scientific data, the following values for daily protein intake can be recommended for different categories of athletes:
- for young male endurance athletes (running, cycling): 1.2-1.4 g/kg;
- for young male strength and muscle mass athletes (bodybuilding, powerlifting): 1.8-2.2 g/kg;
- for female athletes: 1.3 g/kg;
- for older physically active individuals: 1.2-1.4 g/kg.
These values should be viewed as guidelines: they should be used as a starting point and adjusted based on both subjective (the body’s response to the proposed amount of protein, recovery speed) and objective (muscle mass dynamics) indicators.
