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Topic starter
05/08/2021 10:56 am
Is the protein synthesis and muscle protein sparing effect is induced by supplementing freeform BCAAs(L-Leucine specifically) only going to kick in when the BCAAs are taken pre-during-post workout, or should thier use continue on off days as well, particularly during a reduced carb intake. If it only really works when taken around workouts I'd just as soon swap out the 20 grams/day of BCAAs for another chicken breast or fish fillet and save my money
05/08/2021 11:20 am
I would love to know as well. I recently started mega-dosing on bcaa's for my lil' cut and am taking 4 servings (= 40 grams) of Xtend on my cardio-only-/off days.
- V-shape ''Xtend is da shizznit! ''
05/08/2021 11:46 am
this is a really unexplored realm. Certainly leucine has shown the ability to stimulate protein synthesis with or without exercise, but it is my opinion that leucine & exercise will have synergistic effects
Limitations are for people that have them and excuses are for people that need them.
"Per Ferrum, ad astra"... Through iron, the stars
- Mel Siff
Bitch smacking pseudo-scientists since 2010.
05/08/2021 12:10 pm
Anyone know if the synthesis stimulation from leucine is tissue specific ie( in skeletal muscle), or effects multiple tissues to a similar extent?
Also, I can accross an article [ PMID: 15763240 ] regarding BCAA effects on rat hepatocytes, which reported a stimulatory effect dt leucine, and isoleucine antagonised the leucine stimulated mitogenesis in hepatocytes.
1. Is it possible/probable/impossible that isoleucine could have a similar antagonism in skeletal muscle?
2. Also the same article suggests the leucine mechanism is via TGF-a secretion. Is this possible in skeletal muscle?
Drachus - Sorry if these seem a little off topic.
J
05/08/2021 12:36 pm
How much leucine do you think someone would want to use on off days, assuming the goal is to stave off catabolism?
If someone says something about you, and it really bothers you, it's probably because it's true.
05/08/2021 12:58 pm
Anyone know if the synthesis stimulation from leucine is tissue specific ie( in skeletal muscle), or effects multiple tissues to a similar extent?Also, I can accross an article [ PMID: 15763240 ] regarding BCAA effects on rat hepatocytes, which reported a stimulatory effect dt leucine, and isoleucine antagonised the leucine stimulated mitogenesis in hepatocytes.
1. Is it possible/probable/impossible that isoleucine could have a similar antagonism in skeletal muscle?
2. Also the same article suggests the leucine mechanism is via TGF-a secretion. Is this possible in skeletal muscle?Drachus - Sorry if these seem a little off topic.
J
oh yes, it is quite clear it stimulates skeletal muscle protein synthesis... quite clear. But it also stimulates synthesis in several other tissues.
Limitations are for people that have them and excuses are for people that need them.
"Per Ferrum, ad astra"... Through iron, the stars
- Mel Siff
Bitch smacking pseudo-scientists since 2010.
Topic starter
05/08/2021 1:16 pm
Well yeah, but I guess what I am asking is, does the workout provide a similiar "window of opportunity" to get the BCAAs into the system and kickstart the protein synthesis, similiar to the window described for taking high glycemic carbs post workout, or is the body going to respond the same a day or two later since the muscle trauma is still there and needs to be repaired, in which case you should be chugging BCAAs all the time while on a hypertrophy program?
05/08/2021 1:43 pm
don't quite see what you are getting at
Limitations are for people that have them and excuses are for people that need them.
"Per Ferrum, ad astra"... Through iron, the stars
- Mel Siff
Bitch smacking pseudo-scientists since 2010.
05/08/2021 2:13 pm
J Nutr. 2005 Jun;135(6 Suppl):1580S-4S. Related Articles, Links
Click here to read
Observations of branched-chain amino acid administration in humans.Matthews DE.
Department of Medicine, University of Vermont, Burlington, 05405, USA. [email protected]
Since the in vitro study of Buse and Reid in 1975 showing a stimulatory effect of leucine upon rat muscle protein synthesis and reduction in proteolysis, a similar effect has been sought in humans. In 1978, Sherwin demonstrated in humans an improvement in N balance with infusion of leucine in obese subjects fasting to lose weight. A variety of subsequent studies have been performed in humans where leucine alone or the BCAAs have been administered in varying amounts and durations, and the effect upon protein metabolism has been measured. Measurements of changes in muscle amino acid metabolism were made by arteriovenous difference measurements and by biopsies. An anabolic effect of leucine and the branched-chain amino acids (BCAAs) on reduction of muscle protein breakdown was found in these studies, with no measured effect upon muscle protein synthesis. Later studies using stable isotope tracers to define both whole-body protein turnover and leg or arm protein metabolism have similarly concluded that leucine administration specifically induces a reduction in protein breakdown without increasing protein synthesis. This anabolic effect, produced through a reduction of protein breakdown in vivo in humans by leucine is contrary to in vitro studies of rat muscle where stimulation of protein synthesis, has been demonstrated by leucine. Likewise an increase in protein synthesis has also been demonstrated by insulin in rat muscle that is not seen in humans. Of the various studies administering BCAAs or leucine to humans for varying periods of time and amount, the results have been consistent. In addition, no untoward effects have been reported in any of these studies from infusion of the BCAAs at upward 3 times basal flux or 6 times normal dietary intake during the fed portion of the day.
Edit: I'm pretty sure leucine has only been show to stimulate protein synthesis in rats.
05/08/2021 2:37 pm
no, I talked to my professor about this. biolo & wolfe have both shown leucine to stimulate protein synthesis in people. Additionally Wagenmakers has shown that adding leucine to a an oral protein drink further enhances protein synthesis. Also, if you compare different types of protein ie casien and whey you will find that their relative stimulatory effects on protein synthesis are in proportion to their leucine content.
-Layne
Limitations are for people that have them and excuses are for people that need them.
"Per Ferrum, ad astra"... Through iron, the stars
- Mel Siff
Bitch smacking pseudo-scientists since 2010.
05/08/2021 2:55 pm
what about the antagonism of isoleucine?
If isoleucine antagonises the stimulatory effects of leucine, surely sole administration of Leu would be preferable to BCAA.
J
05/08/2021 3:12 pm
Also, if you compare different types of protein ie casien and whey you will find that their relative stimulatory effects on protein synthesis are in proportion to their leucine content.
Makes sense. I recall seeing an abstract stating milk protein was more anabolic than soy protein. I've never compared the amino acid profiles, but I would imagine leucine content is probably the reason.
Another question for you Layne, since Leucine does stimulate protein synthesis, what is the limiting factor?
05/08/2021 3:35 pm
Interesting, are there any available abstracts online? Maybe you can explain this to me, I don't understand how you can stimulate protein synthesis with only one amino acid present. That sounds like you can build a house with just nails, but we know you need wood. Since my knowledge on this subject is minimal, it almost seems that if Leucine can stimulate protein synthesis alone, then it must be causing catabolism somewhere if the amino acid pool is not sufficient.
As i recall - and bear in mind Layne's knowledge of this obliterates the small amount of reading i did a couple of years ago - when it stimulates protein synthesis, it is not the only amino acid present. It simply appears to promote protein synthesis if in higher concentrations than is typical. And i think it is only extreme cases when the amino acid pool would not be sufficient - burns cases and extreme stress etc...
As for abstracts, Layne can probably give you better links to more direct research, but just by throwing "biolo & wolfe" into pubmed, you get a page of abstracts
The "related links" always takes you to hundreds more of similar nature if one abstract interests you. You probably already know that though.
This post was modified 3 years ago by admin
05/08/2021 3:54 pm
Also, if you compare different types of protein ie casien and whey you will find that their relative stimulatory effects on protein synthesis are in proportion to their leucine content.
Makes sense. I recall seeing an abstract stating milk protein was more anabolic than soy protein. I've never compared the amino acid profiles, but I would imagine leucine content is probably the reason.
Another question for you Layne, since Leucine does stimulate protein synthesis, what is the limiting factor?
you aren't thinking about this in proper terms, and it's tough unless you've had classes in cell biology or biochemistry (not trying to sound condescending, it's just the truth). Leucine stimulates protein synthesis, you don't need other amino acids in the mixture because unless you are starving, it's not as if your body is devoid of these amino acids. Now eventually if you don't take any other EAAs in protein synthesis will be limited. The point is the body uses leucine as a sensor for total protein intake. Instead of having a mechanism to moniter the concentrations of every amino acid in the body (which would be energetically expensive) evolution selected for leucine as the marker to tell the body "hey there's enough leucine, so there must be enough total protein" and allows stimulation of protein synthesis.
-Layne
Limitations are for people that have them and excuses are for people that need them.
"Per Ferrum, ad astra"... Through iron, the stars
- Mel Siff
Bitch smacking pseudo-scientists since 2010.
05/08/2021 4:10 pm
How much leucine do you think someone would want to use on off days, assuming the goal is to stave off catabolism?
depends on total protein intake, but i'd say 10g of leucine is plenty (20g of BCAA)
Limitations are for people that have them and excuses are for people that need them.
"Per Ferrum, ad astra"... Through iron, the stars
- Mel Siff
Bitch smacking pseudo-scientists since 2010.
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