Leucine for Muscle Mass

Leucine is one of the most potent amino acids for stimulating muscle protein synthesis and growth in men over 50. Leucine is one of the "Essential Amino Acids" and is also a BCAA or Branched Chain Amino Acid.

Leucine acts as a trigger or a switch. When Leucine levels rise in the blood, it activates a pathway inside muscle cells known as mTOR (Mechanistic Target of Rapamycin) and basically tells the body to BUILD MUSCLE, NOW.

Leucine benefits include the production of growth hormones, the production of energy, and the regulation of blood sugar.

Our primary interest here is in the role it plays in our body's muscular system. It is one of the most important Amino Acids for stimulating Muscle protein synthesis.

We need Leucine in our diets, either from foods or supplements. The link below provides more information on essential amino acid profiles, including Leucine and why it is important, as well as how amino acids support a healthy, functioning body in 50-year-olds and beyond.

Read more on Leucine and the benefits of Leucine for muscle health below.  

WHY IS LEUCINE IMPORTANT?

1. You eat Protein.
2. Your body doesn't respond as strongly.
3. Muscle rebuilds become less efficient.
4. Strength & tone decline.

It is also a favourite amongst athletes due to its ability to boost muscle mass and improve performance.

But as we age and become less responsive to protein intake due to anabolic resistance, we require more Leucine per meal to stimulate the same muscle-building response seen in younger adults. So, over 50, Leucine intake is not optional; it's strategic.

THE LEUCINE THRESHOLD

To properly stimulate muscle protein synthesis, studies suggest that each meal should contain 2.5 - 3 g of Leucine. Too little, and the signal may be weak; above this, the signal gets significantly stronger. This is known as the Leucine Threshold.

Without Adequate Leucine, Protein gets less effective, recovery is slower, and muscle loss can accelerate.

With adequate leucine intake and more productive strength training, it becomes easier to maintain lean muscle mass.

Muscle loss starts from around 30 years old and, in certain cases, younger

From 0.5% to 2% of total muscle mass can be lost per year. Protein and exercise can help prevent this and, in fact, lead to muscle gains.

So if you're over 50, and training. Then, hitting the Leucine threshold, whether you're male or female, at least twice daily, will have a measurable impact on retention and recovery. 

Higher Leucine levels in the blood support muscle maintenance and repair, which can also improve endurance and enhance the immune system.

However, too much Leucine interferes with Niacin production and affects mood. High doses can be toxic.

WHY FOCUS ON LEUCINE?

 Because we focus on function, not fashion, and the goal is simple:

• Preserve muscle mass
• Maintain strength
• Support muscle recovery
• Protect metabolic health

SHOULD YOU SUPPLEMENT LEUCINE ALONE?

Not if you consume enough high-quality Protein. Muscle needs all essential amino acids, not just Leucine (Leu); for that reason, a complete protein is generally superior to isolated BCAAs.

Rather, just hit the Leucine threshold, train with intentna nd ensure you feed your body with high-quality food and avoid UPFs (Ultra Processed Foods)

LEUCINE-RELATED RESEARCH

#1. Leucine, Recovery & Strength in Adults 55-75.

48 health subjects aged 55 - 75 (BMI 19 - 30) were evaluated over 12 weeks. Participants received either leucine-rich supplementation or a placebo approach, alongside moderate exercise.

• Leucine supplementation has been shown to reduce strength loss.
• Improved recovery

Findings included that LeuLeucineunteracted the negative effects of eccentric exercise and reduced exercise-induced strength loss. You can read more on this research from the BMJ Open Sport & Exercise Medicine Journal here. 

#2. Leucine: Strength gains in Resistance Training for Beginners

Leucine supplementation was given to 13 men new to resistance training, and a further 13 received a placebo (lactose). The average BMI was 24.9, and the average age was 28 years. All did supervised training twice a week using 8 standard machines. Testing was done as a baseline and at the end of the period, and was assessed using a repetition maximum and dual-energy X-ray absorptiometry.

The group receiving LeuLeucinemonstrated significantly higher gains in strength across 5 of the 8 exercises.

This was done over 12 weeks. You can read the detailed research at the National Library of Medicine here.

#3. Age demands greater protein requirements

A great article on Leucine muscle synthesis in this research from Today's Dietitian—evidence-based recommendations for optimal protein intake in older people.

#4. The Bigger Picture

Several other studies on Leucine are included in the section The Benefits of Leucine. But across multiple studies, LeuLeucines been shown to:

• Stimulate muscle protein synthesis
• Support strength development
• Improve recovery post resistance exercises
• Help counteract age-related muscle decline

But MOST IMPORTANTLY, Leucine works best as part of a complete high-quality protein source containing all the essential Amino Acids.

LEUCINE SOURCES

There are a number of leucine-rich foods available. Common foods you can include in your daily diet are:

• Whey protein
• Lean beef
  
• Chicken
• Eggs
• Greek yoghurt
• Cottage cheese
• Nuts
• Fish

Whey protein isolate (WPI) is usually among the highest in Leucine content per gram, at 10-12%. Old Bull health Whey Protein = 11.79%. 30 g of a WPI at that level = 3.2g Leucine. 

SUMMARY

Leucine is an essential amino acid found in Protein that your body cannot produce.

Leucine can help gain and retain muscle mass and improve performance. You can get it from supplements or from a well-balanced, healthy diet. 

Read more about Protein in our Protein Guide.