Adding l-leucine to protein powder, food, bcaa, etc

Discussion in 'Diet and Nutrition' started by -BRI-, Dec 29, 2016.

  1. -BRI-

    -BRI- Member

    Oct 8, 2010
    So... I am wondering if someone can give me the break down.

    I'm under the impression that l-leucine is the most cruicial amino acid for a variety of things and especially muscle building. I also heard that it supposedly encourages/increases protein synthesis under different situations. Also heard it stimulates fat loss.

    Are there any medical journals or papers and truths in these matters? I get bulk raw l-leucine, but am i wasting my money? Yes I eat whole food already but hell if it's something relatively cheap anyway I can add it in for the benefit, otherwise if not meh?

    And with BCAAs, they already come with a few different things, i also get it raw bulk (tastes like vomit -- but mix in good protein shake and crap taste gone).
  2. sityslicker1

    sityslicker1 TID Board Of Directors

    Oct 6, 2010
    There is alot of literture out on the subject, however i believe for leucine to show its true potential, it has to be the only amino consumed and best taken alone in/bw or before meals.
  3. MrRippedZilla

    MrRippedZilla VIP Member

    Feb 18, 2015
    L-leucine is the most critical amino acid for anabolism BUT doesn't do anything without the other EAAs - same thing applies to BCAAs.
    As a result, if your overall protein intake is sufficient and comes from quality sources, then supplementing with either of these is a waste of money.

    As for data:
    - Acute trial showing no additive effect of Leucine for squat performance or workout recovery when protein intake was sufficient (1.62g/kg).
    - Review paper that was very negative on Leucine supplementation with this being the key quote:
    ...when free leucine is added in a diet, it is rapidly absorbed and its plasma concentration increases before that of the other amino acids coming from the digestion of the proteins present in the diet.
    Then, muscle protein synthesis machinery may be activated by this leucine increase (via mTOR activation) but cannot translate into protein synthesis because of the lack of simulateous availability of the other amino acids (as substrates for protein synthesis)."
    - Another acute trial showing that a low dose of whey fortified with a Leucine dose equivalent to 25g wasn't as effective as 25g of actual whey protein when it comes to protein synthesis. The same failure was found with low dose whey + the rest of the EAAs except Leucine.
    - The take home message is to supplement with actual whey protein rather than Leucine, EAAs, etc.
    - This final acute trial found that a low dose of whey (6.25g) + 5g of Leucine (2g more than the previous study) was equal to 25g of whey for stimulating protein synthesis.

    So yes, additonal Leucine supplementation is only useful in the face of sub-optimal total protein intake and is never "better" when protein intake is optimal :)
    Go Away, tommyguns2 and admin like this.
  4. admin

    admin Administrator Staff Member

    Aug 11, 2010
    Thank you for the very detailed response MrRippedZilla, hope to see you around here more often.
    MrRippedZilla likes this.
  5. BackAtIt

    BackAtIt MuscleHead

    Oct 3, 2016
    With everyone's genetic potential varying, workout intensity differing, and overall goals being different, what is "optimal" protein sources and intake?....
  6. Tuffoldman

    Tuffoldman VIP Member

    May 23, 2011
    l-leucine can also be used in fat loss when on a carb restriction diet. It mimics glucose to create an insulin response but without causing your liver to store glucose so you can continueto burn fat.

    You can use alone immediately after a workout, get the insulin spike then shortly after use protein and bcaa's as normal and shuttle to your muscles again without causing storage of liver glucose.

    Leucine is a very under used amino by most or at least used properly.
  7. shortz

    shortz Beard of Knowledge VIP

    May 6, 2013
    Alan Aragon ripped apart the studies that showed BCAAs of ANY type being used as a supplement. In fact, he even debunked the research that stated it was good for those in a caloric deficit. He found a lot of the data they collected to either be completely missing based on the results, or the data was just jacked up and manipulated.

    So, he and his colleagues decided to do a study and controlled as many things as possible, and found BCAAs to do absolutely nothing. Hence, the age old quote still stands "Get enough protein from your foods and you shouldn't have to worry about it". In a caloric deficit, your protein intake should be increased to make up for this, so even at your lowest intake, you should be getting more than enough.
    DungeonDweller likes this.
  8. BackAtIt

    BackAtIt MuscleHead

    Oct 3, 2016

    In your opinion, what are the best protein sources to use?

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