Treningsforum

Publisert i går.

"The purpose of present review is to describe the effect of leucine supplementation on skeletal muscle proteolysis suppression in both in vivo and in vitro studies. Most studies, using in vitro methodology, incubated skeletal muscles with leucine with different doses and the results suggests that there is a dose-dependent effect. The same responses can be observed in in vivo studies. Importantly, the leucine effects on skeletal muscle protein synthesis are not always connected to the inhibition of skeletal muscle proteolysis. As a matter of fact, high doses of leucine incubation can promote suppression of muscle proteolysis without additional effects on protein synthesis, and low leucine doses improve skeletal muscle protein synthesis but have no effect on skeletal muscle proteolysis. These research findings may have an important clinical relevancy, because muscle loss in atrophic states would be reversed by specific leucine supplementation doses. Additionally, it has been clearly demonstrated that leucine administration suppresses skeletal muscle proteolysis in various catabolic states. Thus, if protein metabolism changes during different atrophic conditions, it is not surprising that the leucine dose-effect relationship must also change, according to atrophy or pathological state and catabolism magnitude. In conclusion, leucine has a potential role on attenuate skeletal muscle proteolysis. Future studies will help to sharpen the leucine efficacy on skeletal muscle protein degradation during several atrophic states"

Potential antiproteolytic effects of L-leucine: Observations of in vitro and in vivo studies
Nelo E Zanchi , Humberto Nicastro  and Antonio H Lancha Jr

Nutrition & Metabolism 2008, 5:20doi:10.1186/1743-7075-5-20

http://www.nutritionandmetabolism.com/content/pdf/1743-7075-5-20.pdf (http://www.nutritionandmetabolism.com/content/pdf/1743-7075-5-20.pdf)

Her er presantasjonen til Layne Norton fra The 2008 International Society of Sports Nutrition Symposium.
Han fokuserer mye på Leucin og dens effekt på proteinsyntesen. Han viser også til at man ikke bør spise så ofte som 3 timer, og at det er mere fordelaktig å spise med 4-5 timers mellomrom. :)
http://www.biolayne.com/Optimal%20protein%20intake%20and%20meal%20frequency%20to%20support(2003).ppsx (http://www.biolayne.com/Optimal%20protein%20intake%20and%20meal%20frequency%20to%20support(2003).ppsx)

Jeg skjønner for å være helt ærlig ikke så mye av de studiene, men det konkludere altså med at aminosyren leucin er fordelaktig å ta for muskelvekst? Er det noen vits i å ta det som kosttilskudd (som http://www.bulkpowders.co.uk/product.php/260/0/l_leucine (http://www.bulkpowders.co.uk/product.php/260/0/l_leucine) ), eller holder det med vanlig proteinpulver/proteinrik kost? Hvor mange gram må man eventuelt ta? :P

Interessant :)


Ekstra tilførsel av leucin til en allerede balansert aminosyreprofil har ikke vist seg ha noen ekstra effekt:


1. "We conclude that increasing the proportion of leucine in a mixture of EAA can reverse an attenuated response of muscle protein synthesis in elderly but does not result in further stimulation of muscle protein synthesis in young subjects. "

Am J Physiol Endocrinol Metab 291: E381-E387, 2006.


2. "Co-ingestion of leucine with carbohydrate and protein following physical activity does not further elevate muscle protein fractional synthetic rate in elderly men when ample protein is ingested."

British Journal of Nutrition (2008), 99:571-580

1. Norton LE and Layman DK. Leucine regulates translation initiation of protein synthesis in skeletal muscle after exercise. J Nutr. 2006; 136(2):533S-537S.

2. Stipanuk, Martha H. Leucine and protein synthesis: mTOR and beyond. Nutrition Reviews. 2007;Mar;Vol. 65, No. 3:122-9.

3. Padden-Jones D, et al. Amino acid ingestion improves muscle protein synthesis in the young and elderly. Am J Physiol Endocrinol Metab. 2004 Mar;286(3):E321-8.

4. Tipton, KD, et al. Postexercise net protein synthesis in human muscle from orally administered amino acids. Am J Physiol. 1999 Apr;276(4 Pt 1):E628-34.

5. Rasmussen BB, Phillips SM. Contractile and nutritional regulation of human muscle growth. Exerc Sport Sci Rev. 2003 Jul;31(3):127-31.

6. Rieu, Isabelle. Leucine supplementation improves muscle protein synthesis in elderly men independently of hyperaminoacidaemia. J. Physiol. 2006;575;305-15.

?????

Veeeeeeeeeel...

 Leucine and the Modulation of Insulin Release

As many know, the release of insulin has been correlated with many anabolic properties involved with tissue building. Insulin has been proven to stimulate protein synthesis and inhibit protein breakdown when administered both during and post-exercise (Manninen et al, 2006).

Interestingly, in an investigation by Manninen in 2006 involving the supplementation of a carbohydrate, protein hydrolysate, and leucine mixture taken during exercise, it was demonstrated that this mixture leads to greater increases in skeletal muscle hypertrophy and strength vs. a placebo supplement.

It was once believed that insulin secretion was controlled almost entirely by blood glucose concentration. It's since become apparent that amino acids play a crucial role in the regulation of insulin secretion. Certain amino acids have been shown to cause insulin release in humans, even under conditions where blood sugar levels are normal (Manninen et al, 2006).

Of course, in order for most amino acids to effectively stimulate pancreatic beta cell insulin release, permissive levels of blood glucose (2.5 — 5.0 mM) must be present. Interestingly, leucine is an exception, as it's the only amino acid capable of increasing circulating insulin levels regardless of blood glucose concentration (Manninen et al, 2006). The increase of insulin has been shown to decrease the rate of muscle protein degradation.

By limiting protein degradation, leucine may allow for a net protein synthesis post-resistance exercise, leading to greater muscle hypertrophy. Essentially, this insulin response will provide an environment that promotes tissue building, as opposed to tissue breakdown.

Yet here's an important question: if an insulin release produces muscle growth, why wouldn't you simply drink a carbohydrate solution to get this insulin response?

In a study examining plasma insulin release, a 221% greater insulin response was achieved when subjects ingested a high glycemic carbohydrate bolus with protein hydrolysate and leucine as opposed to carbohydrate alone. When the subjects ingested carbohydrate with protein hydrolysate, but without leucine, a 66% greater insulin response was observed than with carbohydrate alone (Manninen et al, 2006).

Based on these results, it's evident that leucine supplementation is beneficial to resistance exercise in terms of its ability to modulate insulin signaling. Post-exercise hyperinsulinaemia (high insulin) supported by hyperaminoacidaemia (high amino acids) induced by protein hydrolysate and leucine ingestion increases net protein deposition in muscle, leading to increased skeletal muscle hypertrophy and strength (Manninen et al, 2006).

So, the bottom line is this: during and post-exercise, it's ideal to ingest a fast-digesting drink of hydrolyzed protein, sugary carbs, and some additional BCAA (especially leucine) because of the combined high blood insulin and high blood amino acid concentrations that accompany such a beverage.

However, based on the research, this type of drink doesn't only work through the modulation of insulin release. Leucine helps grow muscle because it's also a key element in the activation of translational pathways responsible for muscle growth.


Leucine and the Initiation of Translation

Translation, as a review, is the synthesis of protein as directed by mRNA (messenger RNA). It's the first of three stages in protein synthesis, with the other two stages being chain elongation and termination (Norton.et al, 2006). Without translation, there can't be protein synthesis or muscle growth.

Previously, the effects of resistance exercise in relation to protein balance were discussed. It was determined that after exhaustive resistance training, the body is in a catabolic state until nutrition is provided, activating the recovery phase. During this catabolic state, muscle protein synthesis becomes impaired (at the cellular level) due to the inhibition of specific translation initiation factors.

These factors — eIF4G, eIF4E and rpS6 specifically — are what turn on the process of translation and eventually, protein synthesis. And they're controlled by, you guessed it, intracellular insulin signalling and leucine concentrations (Norton.et al, 2006). Therefore, the anabolic effect of exercise and nutrition is likely mediated by activating signal transduction of these initiating factors.

It's been revealed that activation of this translational pathway (displayed below; Layman et al, 2006) is crucial for skeletal muscle recovery and hypertrophy.

As you can see, leucine is necessary for the activation of certain initiation factors. When leucine is ingested, tissue levels increase. This means the inhibition of the above mentioned initiation factors is released. This happens through activation of the protein kinase mammalian target of rapamycin (mTOR above).

Leucine's effect on mTOR is also synergistic with insulin via the phosphoinositol 3-kinase signaling pathway (PI3 above; Norton.et al, 2006). Together, insulin and leucine allow skeletal muscle to coordinate protein synthesis. The figure below provides evidence supporting the above hypothesis.

In the figure above (Blomstrand et al, 2006), BCAA supplementation consumed post-resistance exercise had a significant effect on translation initiating factors p70S6 kinase and mTOR. The role of leucine and other BCAA is to phosphorylate the proteins serine and threonine, which in turn will produce a phosphorylating cascade eventually initiating the translation of protein synthesis.

The fundamental idea to take away is that BCAA, in particularly leucine, reverse the inhibition of translation produced by resistance training. In reversing this inhibition, BCAA will allow for increased muscle hypertrophy through greater levels of protein synthesis.

At this point, you might be wondering why supplemental leucine is necessary when skeletal muscles are already comprised of one-third BCAA. Well, during resistance training, BCAA oxidation in skeletal muscle increases through activation of the branched-chain a-keto acid dehydrogenase (BCKDH).

This means that plasma and intracellular concentrations of leucine decrease. Consequently, the ability of leucine to stimulate insulin release and initiate translation will be diminished until during or post-exercise supplementation is provided.


BCAA, Resistance Training, and Protein Synthesis — What's The Verdict?

So, in the end, the question to ask is this: is leucine supplementation an ergogenic aid in terms of resistance training?

Based on the current literature and the information provided above, the answer is yes. Leucine can act as an ergogenic aid for resistance training athletes based on its ability to modulate insulin signaling and initiate translation of protein synthesis. Both of these factors contribute to greater skeletal muscle hypertrophy and strength."

Veeeeeeeeeel hva? Du vet at du siterer en artikkel fra www.t-nation.com (http://www.t-nation.com) - som profiterer på å selge kosttilskudd - med en teoretisk utbrodering skrevet av en mann (Berardi) som samarbeider med dette selskapet?

Jeg ser for øvrig hvordan denne artikkelen motsier dette:

Samma det. Når artikkelen har vært innom IM forumet så betyr det at det er sant, og kan tas for god fisk rett som det er.

Dessuten, jeg har funnet ut jeg vil også være med å copy-paste random skit...

Mener du at det du copy-paster der motsier at ekstra tilførsel av leucin til en allerede balansert aminosyreprofil ikke har vist seg ha noen ekstra effekt, eller prøver du bare å lage kvalme?

Hvis du mener at det motsier, vennligst forklar hvordan.

Ja det mener jeg at jeg motsier...

"The fundamental idea to take away is that BCAA, in particularly leucine, reverse the inhibition of translation produced by resistance training. In reversing this inhibition, BCAA will allow for increased muscle hypertrophy through greater levels of protein synthesis."

Ja, jeg har fått med meg at du mener det, men du må forklare hvordan. Jeg klarer nemlig ikke å se hvordan det du siterer der motsier at ekstra tilførsel av leucin til en allerede balansert aminosyreprofil ikke har vist seg ha noen ekstra effekt.

Det jeg sier er at ekstra tilskudd av aminosyren leucin i sammenheng med trening, utover det man får i seg via et fullverdig proteintilskudd som f.eks. wheyprotein (som inneholder mye BCAA (leucin, isoleucin og valin)) ikke vil gi noen fordel.

Fordi hvorfor ikke gå overkill på godsakene? Innenfor logiske rammer selvsagt.

Dessuten... siterer Justin Harris. Når det kommer til kosttilskudd har han rett by default.

"The human body requires 20 amino acids for survival. We metabolize left handed amino acids as a necessity for human life.
But, there are also right handed amino acids and racemic (left and right combined) amino acids.
Fuse 22 contains 2 forms of non-metabolizable Leucine.
There is a racemic form and a Beta form. These two amino acids have some incredible effects in the body.
The racemic Leucine causes an increase in Glutamate binding, activating the NMDA receptors. This causes neural excitation, improved cognitive function, and vigilance (tolerance to the discomfort of work).
The Beta form, when combined with L-leucine, causes an insulin release at the pancreas. This creates a non-blood glucose fueled insulin release to stimulate protein synthesis. (L-leucine is already a trigger for protein synthesis)."

Forstår du i det hele tatt hva du siterer?

Dette var et veldig godt spørsmål, veldig spent på svar selv :)

Det er nok som oftest lurt å vite hva det man skal siterer betyr før man siterer det.

Det er jeg helt enig i. Trådstarter burde få med seg dette.

Fint at du er enig. Nå må du bare praktisere det også, så er du i mål.

Trådstarter har fått med seg dette.

Hvis du mener at du har noe relevant for trådens emne å tilføre så er standpunkten jeg forsvarer, og som du tydeligvis argumenterer imot, fortsatt denne: ekstra tilførsel av leucin til en allerede balansert aminosyreprofil vil ikke gi noen ekstra effekt.

På hvilken måte er det du siterer her nedenfor relevant, og hvordan motsier det mitt standpunkt?





Vennligst les og begrunn paragraf 3. i forumets regelverk før du eventuelt svarer.
§3   - Hold debattene saklig og ikke diskutèr noe du ikke klarer å forsvare.

Kan godt og mye om den paragrafen... følger den slavisk, det burde du også gjøre. Vet forresten ikke om jeg engang skal begynne å ta postene dine seriøst ennå.

PS: Hvis du ikke klarer å se at det er relevant, så foreslår jeg at du leser det om igjen.

Ja, denne diskusjonen kom du godt ut av, DCStroyer! :D

Det er nå helt sikkert. Syns nesten synd på Beefcake, gjorde det godt igjen i den andre tråden da. Er jo ikke ond heller. Begynte å få dårlig samvittig for ham. Han er jo en godgutt som gjør sitt beste :)

Jeg har lest det men klarer ikke å se på hvilken måte det sitatet motsier mitt standpunkt. Vennligst opplys meg, og andre som eventuelt lurer på dette.



Takk! :-*

Det jeg skulle frem til var det at er det noen jeg stoler på når det gjelder kosthold og tilskudd så er det Justin Harris. Proff bygger, utdannet innen ernæringsfysiologi i universitetet i Michigan. Reiser verden rundt og holder seminarer om området og har skrevet flere bøker også.

Mitt indre sier meg at jeg bør stole på en som faktisk er bygger og har prøvd ting og tang over lang tid selv og på klienter som Steve Kuclo for å nevne en av de. I tillegg til at han har faglig kompentanse så det griner etter.

Da blekner bokstavelig talt en forsker i hvit frag som aldri har sett en power rack før og som ikke bryr seg så mye om kroppsbygging og vandrer rundt i hvit frakk.

Fint for deg at du liker ham, men hva har det med trådens emne å gjøre? Hva sier denne Justin Harris om ekstra leucininntak utover en allerede balansert aminosyreprofil? Det du siterte ham på tidligere handlet jo bare om generelt om aminosyren, dess isomer og racemat av disse to, og sier ikke noe som helst om mengde så vidt jeg kan se.

Har lest det et eller annet sted... skal finne det når jeg har tid...

For det første er vell ikke Justin Harris proff, og både du og jeg vet at han ikke har blitt så stor på sin kunnskap om ernærig. ;)

Og når det kommer til ernæring så har han til tider mye udokumentert "bygger-svada". Det morsome er at disse så kalt "pre-contest gurus" er veldig glad i å bruke forskning når den er enig med "bygger-sannhetene", men hvis forskningen går i mot deres tro så er det bare tull. Hva vet liksom en mann i en hvit frakk?

Jeg er typen som alltid får skader og arr, og for en stund siden fikk jeg noen skader i ansiktet og kropp som etter 2 måneder sluttet å gro, og som var på god vei til å bli arr. Utseendemessig hadde de sluttet helt å gro. Jeg setter fokuset på arrene i ansiktet her, siden det sjeldent gror like godt som på andre steder i kroppen.

Etter å ha hørt noen venner nevne L Leucine i sammenheng med arr testet jeg dette for moro skyld. Etter 1 uke grodde alle de nye skadene igjen og ble helt fine. Skadene på de andre delene av kroppen var greie, men den virkelige store overraskelsen var at arrene i ansiktet var helt fine igjen. Ingen tegn til rosa eller hvit farge, ingen tegn til at det manglet litt kjøtt fra stedet, absolutt ingen tegn på at det hadde vært noe som helst.

Gjennom hele livet har jeg skadet meg jevt og trutt og fått arr og skader, men aldri opplevd at det stopper helt i en lang stund, for så å akselerere groingen helt vilt som dette.

Er det noen som har lest forskning angående Leucine og groing av skader? Og hvor ofte kan man egentlig ta Leucine sammenhengende?

Siden det som vist her er Leucine som i stor grad styrer eller aktiviserer protiensyntesen, som igjen er danning av nytt vev så er ikke noe usansynlighet. ;)