T Nation

BCAA/Leucine Supplementation

Hello - I just read this article and realized it is 11 years old. Does anyone know if the conclusions are still holding, or are there new studies to consider?


You Get An “Incomplete” On Your Home Work

You wouldn’t be asking this question if you can done you home work.

Spoon Feeding

By doing your own research, you will find that…

  1. Leucine triggers the “Anabolic” muscle building process, mTOR/Mammalian Target of Rapamycin.

  2. Leucine is most effective when combined with complete proteins.

  3. 2.5 to 4.5 gram of Leucine in one serving is necessary to trigger mTOR, build muscle mass.

Younger individual need a minimum of 2.5 gram of Leucine per serving; older individuals require over 3 gram of a serving of Leucine to elicit the same effect.

To reiterate, Leucine is most effective when combined with complete proteins.


Approximately, 30 gram of a quality proteins is necessary to obtain 2.5 grams of Leucine; Whey, Casein, Meats, Milk, Cheese, etc.

Refractory Meal Periods

Muscle Protein Synthesis is optimized when protein with meals is consumed every 4 - 5 hours, not the old dogma of every three hours that is perpetuated by Bodybuilders.

However, it appears that their may be a “Window of Opportunity” to spike Muscle Protein Synthesis, mTOR, if Leucine is ingested about 2.5 hours after one meal and 2.5 hour prior to the next meal.

Research Source

Dr Layne Norton (PhD Nutrition/Pro Card Natural Bodybuilder/Powerlifter) is one of the leaders in the field of Leucine Research. Google Norton for additional information.

Kenny Croxdale