Blog Post

The Complete Guide to Protein for Athletes

Protein for Athletes Featured Immage

Optimising protein intake can help an athlete improve muscle growth and recovery. It is an important topic that is worth knowing a lot about.

Total Amount to Aim For

The most important aspect of nailing your protein intake is consuming a sufficient total amount.

For those looking to optimise muscle growth, the evidence-based range is 1.6-2.2g of protein, per kg of body weight, per day.

For an 80kg athlete, this would be 128-176g per day.

The 1.6g/kg number seems to be enough to maximise muscle growth for almost all athletes. The 2.2g/kg number is added as an upper limit to help cover outliers.

These numbers are also based off athletes who are relatively lean. My interpretation is that they are based off athletes that ~10-15% for men and 18-23% for women.

Our protein needs are more closely linked to how much fat-free mass we have than they are to our body weight

If you are leaner than those numbers, I would aim for 1.8-2.4g/kg/day.

If you have more body fat, aiming for 1.4-2.0g/kg would be more appropriate.

Going above the top end of this range is not actively detrimental. It is safe from a health perspective for those without pre-existing conditions. It could take away from the opportunity to consume more carbohydrates or fats though, and the micronutrients associated with those foods too.

Situations Where Total Protein Intake Should Be Different

High Protein Foods

These numbers are based on athletes trying to optimise muscle growth.

Should athletes always be striving to maximise muscle growth?

There are certain athletes who just want to try to maintain the muscle mass they have already built.

In those cases, you can argue that dropping down to a slightly lower target such as 1.2g/kg/day makes sense. This leaves more room for carbohydrates to help fuel performance.

Other examples are endurance athletes. The current consensus range is that endurance athletes should aim for 1.2-1.4g/kg/day.

Endurance athletes typically have higher calorie expenditures than most other sports. This means that as a percentage of their total intake, this is an even lower percentage than most other sports.

Another exception is athletes in a calorie deficit who are either:

  1. In a large calorie deficit.
  2. Quite lean already.

Under those circumstances, it is harder to retain muscle. The research shows that increasing to 2.3-3.1g/kg of fat-free mass would be a more appropriate target.

Note: This recommendation is based on fat-free mass, whereas other ones were based on total body mass.

Distribution of Protein

Muscle protein synthesis often gets maximised after as little as 20-40g of protein in a meal.

This is not a limit on how much the body can absorb or anything. Total protein intake per day is far more important than distribution.

The research indicates that distribution does still matter though.

To optimise muscle growth, the evidence indicates that consuming 0.4-0.55g/kg of protein per meal, over 4-6 meals per day would be optimal.

Having at least 0.4g/kg (often 20-40g of protein) in each of these meals is important. This is usually how much it takes to have enough leucine to meet the leucine threshold. This threshold is important for maximising muscle protein synthesis.

Leucine is not the only amino acid that matters. But consuming at least 2-3g of leucine per protein rich meal is a good idea.

For those that would struggle with 4+ protein-rich meals per day, 3 is likely almost as good, assuming total protein intake is sufficient.

A Note on Intermittent Fasting

Distributing protein in this fashion involves consuming a protein-rich meal every 3-4 hours.

Intermittent fasting does the opposite and involves a long period of time without protein being consumed.

Based on the research, this would not be optimal for muscle growth.

There is minimal research on fasting and muscle growth since muscle growth usually also involves a calorie surplus. Almost all fasting studies involve a calorie deficit.

But the research involving calorie deficits still shows good retention of muscle when protein and calories are appropriate.

If 20-40g of protein in a sitting was a limit on how much we could absorb, this would not be the case.

If somebody wished to optimise this aspect though, an option could be to consume something that contained ~30g of protein with minimal fats or carbs during their fasting window.

This would break the fast of course. But it is an option.

Specific Timing

Man drinking a protein shake

The anabolic window is often thought of as either:

  1. Needing protein as soon as possible after your workout. Often within 1-hour maximum.
  2. Not important at all.

The answer is somewhere in the middle.

It is beneficial to have >0.4g/kg of protein within 3-5 hours around the time of your workout.

This could be before or after.

An example of research supporting this involved identifying that a pre-workout protein shake is as effective as post-workout protein.

The 5-hour aspect is only relevant for people who have consumed a large amount of protein a few hours prior to training. This is because protein takes time to digest and be absorbed.

This means that if you were to train fasted, you have roughly a 1.5-hour window post-workout to get protein in.

Outside of fasted training, you likely do not need to think much about this aspect. If you are already consuming sufficient total protein and distributing it across the day, you will already be ticking this box.

Protein Quality

Protein quality is typically dictated by the amino acid profile of a protein source. Another aspect is the digestibility of these amino acids.

One example of how the amino acid profile matters is the leucine threshold. Consuming leucine-rich protein sources can help muscle growth.

Leucine Threshold

Collagen protein is an example of how this could matter. It has a unique amino acid profile. It is particularly low in leucine.

There is more to muscle protein synthesis than just leucine though. One study compared collagen vs whey protein for growth, with a matched amount of leucine. Even with leucine added to collagen, whey protein still outperformed.

If you do the following, you likely do not need to think about protein quality much:

  1. Consume a relatively high protein intake (1.6g/kg/day or higher).
  2. Consume a variety of protein sources, including animal products.

By doing those two things, you will have an abundance of all amino acids. There should be no specific gaps taking this approach.

Plant Based vs Animal Based

Vegan Protein Sources

Plant-based protein sources often are low in certain important amino acids. Their digestibility score is often lower too.

If you follow a plant-based diet, it might require a bit of planning.

Although some protein sources might be considered incomplete due to having sub-optimal amounts of amino acids, this is not as big of an issue as it sounds. If you consume a variety of protein sources across the day, this naturally sorts itself out.

The digestibility aspect sounds scarier than it is too. The way to overcome this that has been proposed is just to aim for a slightly higher total protein intake, such as >1.8g/kg/day.

This can require planning on a plant-based diet. It can also be made significantly easier with protein supplementation too though.

For those who are interested, a study came out relatively recently indicating that those on plant-based diets do not have higher total protein needs.

It still seems prudent to aim for a slightly higher than you otherwise would have. This study does not just suddenly change everything we know about protein. But it could be reassuring to see that if needs are higher, they are likely not significantly higher.

Protein Supplements

Protein Powder

Protein supplements should be thought of simply as convenient ways to consume high-quality protein.

It is almost like a quality food source of protein. Although it does not come alongside the micronutrients you would have gotten in food.

Whey protein is the gold standard form of protein.

Other options perform equally well though.

Soy protein is a complete form of protein.

Pea protein is an incomplete protein source, but it leads to a similar amount of muscle protein synthesis.

You could solve the amino acid profile problem by combining it with another protein source such as rice protein too. This contains the amino acids that pea protein is lacking in.

BCAAs and EAAs are often promoted as beneficial for muscle growth. Under the context of a diet that has high enough total protein, from a variety of sources, there is typically no additional benefit though.

I would not encourage relying on protein supplements for a large percentage of your intake. But they can be a convenient way to help meet your needs.

Practical Summary

Protein intake is an important topic for athletes. It can be complex when you look deeply into it. The pyramid of priorities below really simplifies it though.

Protein Prioritisation Pyramid

Prioritisation makes understanding this topic easier.

Instead of focusing on everything equally, focus on the most important stuff the most.

Total protein intake is the most important thing.

Distributing it across the day makes it easier to consume all of that protein. It also takes care of the timing aspect in most cases too.

Consuming a wide variety of protein sources and a sufficient total amount of protein often takes care of quality. In some cases, such as plant-based diets, it might need to be more well thought out.

And supplementation is not magical. It is just a convenient way of adding high-quality protein to your diet at a time that suits you.

By Aidan Muir

Aidan is a Brisbane based dietitian who prides himself on staying up-to-date with evidence-based approaches to dietetic intervention. He has long been interested in all things nutrition, particularly the effects of different dietary approaches on body composition and sports performance. Due to this passion, he has built up an extensive knowledge base and experience in multiple areas of nutrition and is able to help clients with a variety of conditions. One of Aidan’s main strengths is his ability to adapt plans based on the client's desires. By having such a thorough understanding of optimal nutrition for different situations he is able to develop detailed meal plans and guidance for clients that can contribute to improving the clients overall quality of life and performance. He offers services both in-person and online.