Not all protein is created equal. Learn what science understands by the “leucine threshold” – and why you should portion your proteins correctly.
Have you ever wondered why 30 grams of whey protein can be more effective for muscle building than 30 grams of protein from peas or wheat?
The answer lies not only in the general amino acid profile, but in a very specific essential amino acid: Leucine.
The "light switch" for your muscles (The mTOR pathway)
In your muscle cells, there is a central switch for muscle growth, the enzyme mTOR (mechanistic Target of Rapamycin). When this switch is on, muscle protein synthesis (MPS) is in full swing – your body builds new tissue.
Sports science (including studies by Dr. Layne Norton) has found that leucine acts like the key for this switch. For mTOR to be fully activated, a certain amount of leucine must arrive in the bloodstream at once – this is referred to as the leucine threshold (Leucine Trigger).
The facts about the leucine threshold:
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The magic dose: You need about 2.5 to 3 grams of pure leucine per meal to maximally stimulate muscle protein synthesis.
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Why animal protein often wins: Whey protein or low-fat quark naturally contain a lot of leucine (approx. 10–11%). Plant-based proteins often have a lower leucine content (approx. 6–8%), which is why you need a slightly larger portion to achieve the same effect.
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Dividing proteins makes sense: Instead of eating your entire daily protein intake in a single huge meal, it is scientifically more sensible to distribute 3 to 5 protein portions throughout the day (each with at least 30g of high-quality protein). This way, you flip the "light switch" multiple times a day!
Conclusion: Don't just pay attention to your total protein intake, but ensure that each main meal contains enough leucine.
KRAFTMODUS Tip: A simple scoop of protein powder in your KRAFTMODUS stainless steel shaker guarantees you the perfect dose of leucine for maximum muscle activation after your workout.