Why protein plays a key role in muscle health

Why protein plays a key role in muscle health

Team ErbologyErbology

We met with Omar Labarta, the founder of OLab Performance and a personal trainer with over 14 years of experience, to discuss muscle health and the importance of protein in nutrition.

April 27, 2022 5:12 pm

Since graduating from Brunel University with a masters degree in sports science, Omar Labarta has gone on to work as a personal trainer. He specialises in strength and conditioning for different fitness companies and high performance centres.

He has since embarked on his journey as a self-employed personal trainer, launching his own brand, OLab Performance.

Today, the Spanish fitness advocate has 14 years of experience in the field and teaches classes across London. He uses a combination of strength conditioning, muay thai and nutrition to improve the health of his clients.

We were lucky enough to pick Omar’s brains over the role of protein in building muscle mass, a key topic for any regular gym-goer.

First off, what is skeletal muscle mass?

Skeletal muscle mass (SMM) is an integral body tissue. Together with the nervous system and bones, it is responsible for your body’s movements..

Beside its role in allowing you to move, skeletal muscle is the largest site of ‘postprandial glucose disposal’. This is a scientific term which just means that your muscles help process the sugar from the food you eat. It’s also a site for lipid oxidation (the breakdown of fats). 

Your skeletal muscle mass is also an important factor in your basal metabolic rate. This is the amount of calories you need to function when you’re ‘at rest’. All this means that preserving your skeletal muscle mass is  essential to maintain your metabolic health.

How do we develop skeletal muscle mass?

Skeletal muscle mass is dictated by the difference between how much muscle you’re making (muscle protein synthesis (MPS)) and how much  muscle you’re losing (muscle protein breakdown (MPB)).

To put it simply, if you’re making as much muscle as you’re losing, your overall skeletal muscle mass will stay the same. If you’re building more muscle than you lose, your muscle mass will increase. (This is called hypertrophy.) And, if you’re losing more muscle than you’re building, you will lose muscle mass (atrophy).

You can control this process using two important factors. The first is protein from your diet, and the second is resistance training.

What role does protein play?

Protein provides the structural base for all tissues and organs. During normal daily activity, and especially during exercise, proteins are broken down.

In order to repair muscle structure and function, you have to feed your body with protein.

Protein also plays an important role in maintenance of immune function. This is especially true in athletes and physically active people.(1)

Beside the importance of maintaining muscle mass from a health point of view, there is plenty of interest from the recreational fitness sphere, too. Active individuals and athletes make use of a protein-rich diet, combined with resistance training, to help them build muscle mass.

How much protein do I need?

It’s clear how essential the protein is in order to maintain a healthy skeletal muscle mass. But how much do you actually need? Does everyone need the same amount? And when’s best to get it?

Unfortunately, there’s no simple answer to these questions. What is clear is that recommending a total daily amount of protein is not enough to maintain a healthy SMM system.

You also have to take lots of variables into consideration such as age and body mass. In addition to these factors, the source (and quality) of the protein, the quantity you eat, and even when you eat it affect muscle protein synthesis. All these things are important in maintaining or increasing muscle mass.

Why protein plays a key role in muscle health
Why protein plays a key role in muscle health
Why protein plays a key role in muscle health
Why protein plays a key role in muscle health

"Protein provides the structural base for all tissues and organs."


Despite the recommended dietary allowance for protein (RDA) being ~0.8gr/kg of body mass per day for normal adults, studies suggest that this amount may be inadequate for certain people.

These groups include people who are trying to maintain or increase their muscle mass in a resistance training programme. However, it may also be insufficient for older adults trying to maintain their muscle health, and people who are following an energy restriction diet.(2)(3)

Any rules of thumb to follow?

It might be tricky to give an exact figure as there are so many factors involved. However, there are a couple of interesting studies that show just how much variability there is in the amount of protein needed by different people.

One study showed that 0.24g/kg per body mass of protein stimulated muscle protein synthesis in young adults the best. However, older adults needed 68% more to equal those results.(4)

Another review suggests that when muscle mass gain is the goal after resistance training, daily protein intake should range between 1.6 to 2.2g/kg of body weight (110-160g/day for a 70kg adult, ~20g per meal).(3)

If you’re involved in a serious resistance training programme, the ideal amount of protein for you will be higher than if you’re less active. Body mass also plays a role, so heavier athletes need a greater amount of protein per meal than their lighter counterparts.

In essence, older adults, active people and heavier people need more protein than others.

You can achieve your daily goals by adding a good source of protein to each meal or incorporating high quality protein supplements (e.g. Erbology Hemp Powder).

Low calorie diet

In a calorie-restricted diet, the protein intake dose requirements appear to be even higher ~2.3–3.1g/kg per day. That’s triple the recommended guidelines (0.8g/kg) for preserving lean body mass!

Leaner individuals with experience in resistance training fall in the higher part of the spectrum. On the other hand, less exercise-advanced subjects should be aiming the lower part of this range.(3)

When should you take protein?

According to a recent study,(5)  protein-rich meals should ideally be spread over the course of the day, separated by ~3–5 hours. This should maximise muscle protein synthesis. Timing the protein intake close to exercise is recommended, although not critical, for best results.

What’s more, different studies have shown that the ingestion of casein protein a couple of hours before bed time increases muscle anabolism (the building of muscle tissue).(6,7).

However, the dose must be higher (~0.5-0.6 g/kg per meal or 30/40gr) in order to kick-start muscle protein synthesis, and balance out the net loss of muscle that occurs naturally during sleep.

Protein type and quality

Not all protein is the same, and some sources are better than others.

High quality whey protein comes top of the class. It’s easy and quick to digest, and contains a high proportion of essential amino acids, including leucine. It stimulates higher rates of protein synthesis than other types of protein(8).

Lower quality protein sources like soya or wheat protein don’t seem to promote protein synthesis quite as well as whey.(9)

Leucine is the key amino acid which contributes to muscle protein synthesis, so it’s definitely something to look out for on packaging. Leucine can even compensate for low quality and quantity of protein sources in promoting MPS (10). The recommended dose is about 2-3g.  

Thanks to leucine’s super protein building properties, it can be very useful for people who struggle to reach the recommended doses listed above. This is often the case with older people.

For people following a calorie-restricted diet, it’s even more important to make sure that the source of protein is as high-quality as possible. This helps to increase its ability to suppress your appetite, helping you stick to your diet.

To summarise

Here are my top tips, taken from the excellent recent reviews by well renowned scientists in the area (3):

  • Individuals involved in serious resistance training programmes should have a daily protein intake of ~1.6g/kg per day and up to 2.2g/kg per day
  •  ~0.3g/kg body weight/per meal (~20g/kg per meal for a 70kg person).
  • Young men and likely women who exercise regularly should intake ~0.4g/kg body weight after a period of resistance training or rest period.
  • Protein meals should be separated by 3–5 hours to maximise MPS (ie. ~0.3/0.4g/kg of body mass of protein in 4 to 5 meals spread during the day)
  • Make sure you’re consuming high-quality protein, with plenty of leucine.
  • If you’re using lower quality protein, look for types that contain additional leucine. It can compensate for low protein quality and quantity. This can be useful for populations that struggle to reach the above recommended doses, like older adults.
  • Before bed, increase your protein intake to ~0.5-0.6 g/kg per meal. Casein is a great option for this.
  • If you’re following a calorie-restricted diet, aim for 2.3–3.1 g/kg per day of high quality protein.
  • Resistance training with high protein intake should be a must if you’re restricting your calories and looking to maintain lean mass.

Future research

Despite the great number of studies focusing on the role of protein in skeletal muscle mass health, more research must be done in order to better understand how protein and its different sources (ie. plant-based) affect different type of populations, especially in females due to the lack of studies with women.