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I denna tråd kommer jag posta lite studier på intressanta saker för oss tränande.
Ämnen som funkar för oss och ämnen som inte funkar.Och alla ni kostexperter och alla pubmed junkies skriv ni ochså.
Sen skulle jag vilja uppmana dom svenska tillverkare att nåt i deras sortiment prövas i kliniska oberoende studier.
Speciellt något som ni tror har nån betydelse för oss konsumenter.
Det tjänar ni på först och främst att ni har bevis att det funkar.Som i fallet med Vitargo och företaget Swecarb vars produkt har nu testats oberoende av Karolinska institutet och nu av Dr Paul Greenhaff.
Läs detta mkt intressant.
[http://www.informaworld.com/smpp/content~content=a781710908?words=vitargo&hash=429828784]Post-exercise ingestion of a unique, high molecular weight glucose polymer solution improves performance during a subsequent bout of cycling exercise
Authors: Francis B. Stephens a; Marc Roig a; Gerald Armstrong a; Paul L. Greenhaff a
Affiliation: a Centre for Integrated Systems Biology and Medicine, School of Biomedical Sciences, Queen’s Medical Centre, University of Nottingham, Nottingham, UKDOI: 10.1080/02640410701361548
Publication Frequency: 14 issues per year
Published in: Journal of Sports Sciences, Volume 26, Issue 2 January 2008 , pages 149 – 154
First Published on: 27 August 2007
Subject: Sport & Exercise Science;
:emo-thumbEftersom du gillar BCAA så mycket så bidrar jag med denna.
Observations of Branched-Chain Amino Acid Administration in Humans
The American Society for Nutritional Sciences J. Nutr. 135:1580S-1584S, June 2005 : 4th Amino Acid Assessment Workshop
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.
[http://jn.nutrition.org/cgi/content/full/135/6/1580S http://jn.nutrition.org/cgi/content/full/135/6/1580S%5D
Här är en till som är intressant. I o f på råttor och avser infuserade aminosyror men den är intressant med tanke på diskussionerna om BCAA kontra EAA. Vore kul om det fanns någon liknande studie på människor.
American Society for Nutrition J. Nutr. 136:234S-236S, January 2006
Branched-Chain Amino Acids: Metabolism, Physiological Function, and Application: Session II[/b]
Modulations of Muscle Protein Metabolism by Branched-Chain Amino Acids in
Normal and Muscle-Atrophying RatsIt has been shown that BCAAs, especially leucine, regulate skeletal muscle protein metabolism. However, it remains unclear how BCAAs regulate muscle protein metabolism and lead to anabolism in vivo. We examined muscle protein synthesis rate and breakdown rate simultaneously during BCAA infusion in muscle atrophy models as well as in normal healthy rats. Corticosterone-treated rats and hindlimb-immobilized rats were used as muscle atrophy models. Muscle protein synthesis rate and breakdown rate were measured as phenylalanine kinetics across the hindlimb. In anesthetized normal rats, BCAAs stimulated muscle protein synthesis despite low insulin concentration and did not suppress muscle protein breakdown. In corticosterone-treated rats, BCAAs failed to restore inhibited muscle protein synthesis, but reduced muscle protein breakdown. Immobilization of hindlimb increased muscle protein breakdown within a day. BCAAs did not change muscle protein metabolism, although essential amino acids (EAAs) suppressed muscle protein breakdown in hindlimb-immobilized rats. We also evaluated changes of fractional synthesis rate (FSR) of skeletal muscle protein during infusion of leucine alone or EAAs for 4 h in anesthetized normal rats. FSR showed a transient increase at 15–30 min of leucine infusion and then declined, whereas FSR stayed elevated throughout EAA infusion. We concluded that 1) BCAAs primarily stimulate muscle protein synthesis in normal rats independently of insulin; 2) EAAs are required to maintain the BCAA stimulation of muscle protein synthesis; and 3) The effects of BCAAs on muscle protein metabolism differ between atrophy models.
[http://jn.nutrition.org/cgi/content/full/136/1/234S#BIB40 http://jn.nutrition.org/cgi/content/full/136/1/234S#BIB40%5D
En allmänt sammanfattande text om kreatinsupplementering sprängfylld med referenser för den som vill läsa studier om saken. Alltså i sig ingen studie men en mycket bra sammanställning, läsvärd för den som är intresserad av kreatin. Och enskilda studier finns det som sagt gott om i referenslistan:
[http://www.pubmedcentral.nih.gov/picrender.fcgi?tool=pmcentrez&artid=2048496&blobtype=pdf]
International Society of Sports Nutrition position stand: creatine
supplementation and exercise. Journal of the International Society of Sports Nutrition 2007, 4:6.I denna studie visade forskarna att ett intag av enbart de tre grenade aminosyrorna(BCAA) i samband med styrketräning.
Var tillräcklig att aktivera p70s6 i en timme och två timmar efter träning
En aktivering av p70s6 är nödvändig för att proteinsyntesen ska stimuleras i samband med styrketräning.
I tidningen Svensk idrottsforskning sammanfattade man den här studien att mTOR fosforyleringen med andra ord aktiveringen av proteinsyntesen,ökade.
Vilket tyder på att BCAA aktiverar proteinsyntesen(mTor) via en ännu okänd signalväg.Am J Physiol Endocrinol Metab. 2004 Jul;287(1):E1-7.
Branched-chain amino acids increase p70S6k phosphorylation in human skeletal muscle after resistance exercise.
Univ. College of Physical Education and Sports, Box 5626, S-114 86 Stockholm, Sweden.
The aim of the study was to investigate the effect of resistance exercise alone or in combination with oral intake of branched-chain amino acids (BCAA) on phosphorylation of the 70-kDa S6 protein kinase (p70(S6k)) and mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK1/2), and p38 MAPK in skeletal muscle. Seven male subjects performed one session of quadriceps muscle resistance training (4 x 10 repetitions at 80% of one repetition maximum) on two occasions. In a randomized order, double-blind, crossover test, subjects ingested a solution of BCAA or placebo during and after exercise. Ingestion of BCAA increased plasma concentrations of isoleucine, leucine, and valine during exercise and throughout recovery after exercise (2 h postexercise), whereas no change was noted after the placebo trial. Resistance exercise led to a robust increase in p70(S6k) phosphorylation at Ser(424) and/or Thr(421), which persisted 1 and 2 h after exercise. BCAA ingestion further enhanced p70(S6k) phosphorylation 3.5-fold during recovery. p70(S6k) phosphorylation at Thr(389) was unaltered directly after resistance exercise. However, during recovery, Thr(389) phosphorylation was profoundly increased, but only during the BCAA trial. Furthermore, phosphorylation of the ribosomal protein S6 was also increased in the recovery period only during the BCAA trial. Exercise led to a marked increase in ERK1/2 and p38 MAPK phosphorylation, which was completely suppressed upon recovery and unaltered by BCAA. In conclusion, BCAA, ingested during and after resistance exercise, mediate signal transduction through p70(S6k) in skeletal muscle.
PMID: 14998784 [PubMed – indexed for MEDLINE]
PatArnold wrote:I denna studie visade forskarna att ett intag av enbart de tre grenade aminosyrorna(BCAA) i samband med styrketräning.
Var tillräcklig att aktivera p70s6 i en timme och två timmar efter träning
En aktivering av p70s6 är nödvändig för att proteinsyntesen ska stimuleras i samband med styrketräning.Visserligen i jämförelse med smaksatt vatten. Kanske var den uppmätta effekten bättre än väntat men hade varit mer intressant att se skillnad mellan en vanlig gainer t.ex.
Att aminosyror stimulerar proteinsyntesen bättre än vatten känns ju föga förvånande.
Meningen med denna studie var att undersöka om BCAA överhuvudtaget stimulerar proteinsyntesen.
Vilket BCAA gjorde men som du säger Eddie det vore intressant om det kunde göras en större studie.
Där man kollar vilken sammansättning stimulerar proteinsyntesen bäst.
En gainer med vasslehydrolysate och leucin,EAA eller BCAA.
Men än så länge har det varit placebo mot verksamt ämne och så görs alla studier men det vet du=)PatArnold wrote:Meningen med denna studie var att undersöka om BCAA överhuvudtaget stimulerar proteinsyntesen.
Vilket BCAA gjorde men som du säger Eddie det vore intressant om det kunde göras en större studie.
Där man kollar vilken sammansättning stimulerar proteinsyntesen bäst.
En gainer med vasslehydrolysate och leucin,EAA eller BCAA.
Men än så länge har det varit placebo mot verksamt ämne och så görs alla studier men det vet du=)Att det stimulerar translationsaktivering är solklart. Även i artikeln ”Observations of Branched-Chain Amino Acid Administration in Humans” som jag länkade till ovan nämnet det. Det man vill se är om detta verkligen resulterar i ökad muskelproteinsyntes.
Finns två studier vid ”bed rest”. Den ena med BCAA vs NEAA och den andra med EAA. Syftet med studierna är att se hur de olika aminosyrorna påverkar MPS och hurvida de kan minska muskelkatabolism vid inaktivitet. Har inte lusläst och jämfört resultaten, metoder osv men av det lilla jag har läst så tycker inte att BCAA verkar lika effektivt som EAA under dessa förhållanden. Detta är givetvis inte heller direkt överförbart till effekten vid träning.
EAA-studie:
”A loss of muscle mass and functional capacity are two of the more deleterious consequences of prolonged muscular inactivity. Our data demonstrate that essential amino acid and carbohydrate supplementation during 28 d of bedrest provided an anabolic stimulus capable of ameliorating the loss of lean muscle mass.”
[http://jcem.endojournals.org/cgi/content/full/89/9/4351 Essential Amino Acid and Carbohydrate Supplementation Ameliorates Muscle Protein Loss in Humans during 28 Days Bedrest ]
BCAA-studie:”Supplemental BCAAs of the diet did not measurably affect the whole body protein synthesis rate (15N algal amino acids) or breakdown rate (15N algal amino acids). Neither was there any direct effect on muscle protein synthesis or muscle protein breakdown as measured by the urinary 3-methyl histidine excretion. Because there was no difference in any of the parameters of protein kinetics measured, it follows that the supplemental BCAAs had little if any impact on protein kinetics. ”
[http://jap.physiology.org/cgi/content/full/94/4/1345 Branched-chain amino acid supplementation during bed rest: effect on recovery.]
Jag tyckte att studien,Observations of Branched-Chain Amino Acid Administration in Humans.Antydde mer att BCAA är mer anti-kataboliskt än att det stimulerar MPS(muskelproteinsyntesen).
Men i studien som jag bifogade så visar det att BCAA aktiverar muskelprotein syntesen.
Och med tanke på att BCAA aktiverar p70s6 som är nödvändigt för att muskelproteinsyntes ska stimuleras.
Så stimulerar BCAA muskelproteinsyntesen men via en okänd signalväg.
Så mer forskning behövs för att utreda detta annars kan man testa BCAA och se vad det gör.
Och hitills är jag väldigt nöjd med BCAA och tycker att jag får nåt av det.PatArnold wrote:Jag tyckte att studien,Observations of Branched-Chain Amino Acid Administration in Humans.Antydde mer att BCAA är mer anti-kataboliskt än att det stimulerar MPS(muskelproteinsyntesen)..Det är det flera studier tycks visa.
Men i studien som jag bifogade så visar det att BCAA aktiverar muskelprotein syntesen.
Ja, men inte att det resulterade i muskeluppbyggnad.
Här är en annan studie på grisar som är ganska intressant. Inte kanske heller den direkt överförbar på tränande individer:
In the present study, 7- and 26-day-old pigs were fasted overnight and infused with leucine (0 or 400 µmol·kg–1·h–1) for 120 min to raise leucine within the postprandial range. The leucine was infused in the presence or absence of a replacement AA mixture (without leucine) to maintain baseline plasma AA levels. AA administration prevented the leucine-induced reduction in plasma AA in both age groups. At 7 days, leucine infusion alone increased eukaryotic initiation factor (eIF) 4E binding protein-1 (4E-BP1) phosphorylation, decreased inactive 4E-BP1·eIF4E complex abundance, and increased active eIF4G·eIF4E complex formation in skeletal muscle; leucine infusion with replacement AA also stimulated these, as well as 70-kDa ribosomal protein S6 kinase, ribosomal protein S6, and eIF4G phosphorylation. At 26 days, leucine infusion alone increased 4E-BP1 phosphorylation and decreased the inactive 4E-BP1·eIF4E complex only; leucine with AA also stimulated these, as well as 70-kDa ribosomal protein S6 kinase and ribosomal protein S6 phosphorylation. Muscle protein synthesis was increased in 7-day-old (+60%) and 26-day-old (+40%) pigs infused with leucine and replacement AA but not with leucine alone. Thus the ability of leucine to stimulate eIF4F formation and protein synthesis in skeletal muscle is dependent on AA availability and age.
[http://ajpendo.physiology.org/cgi/content/abstract/293/6/E1615 Amino acid availability and age affect the leucine stimulation of protein synthesis and eIF4F formation in muscle]
Nej inte att det resulterade i muskelökning för att då måste studietiden vara längre för att mäta nån muskelökning.
Men det intressanta med den svenska studien,Branched-chain amino acids increase p70S6k phosphorylation in human skeletal muscle after resistance exercise.
Är att styrketräning i sig stimulerar muskelproteinsyntesen.
Och att BCAA ökade muskelproteinsyntesen 3.5 ggr mer under återhämtnings fasen.
Resistance exercise led to a robust increase in p70(S6k) phosphorylation at Ser(424) and/or Thr(421), which persisted 1 and 2 h after exercise. BCAA ingestion further enhanced p70(S6k) phosphorylation 3.5-fold during recovery.L-arginine reduces exercise-induced increase in plasma lactate and ammonia.
Author: Schaefer, A : Piquard, F : Geny, B : Doutreleau, S : Lampert, E : Mettauer, B : Lonsdorfer, J
Int-J-Sports-Med. 2002 Aug; 23(6): 403-7
To investigate the effect of L-arginine supplementation (L-ARG) on physiological and metabolic changes during exercise, we determined in a double-blind study the cardiorespiratory (heart rate, oxygen consumption (VO(2)) and carbon dioxide production (VCO(2)) and the metabolic (lactate and ammonia) responses to maximal exercise after either an intravenous L-ARG hydrochloride salt or placebo load in 8 healthy subjects. Exercise-induced increases in heart rate, VO(2) and VCO(2) were not significantly different after L-ARG or placebo. By contrast, peak plasma ammonia and lactate were significantly decreased after L-ARG load (60.6 +/- 8.2 vs. 73.1 +/- 9.1 micro mol x l(-1), p less than 0.01 and 7.1 +/- 0.7 vs. 8.2 +/- 1.1 mmol x l(-1), p less than 0.01, for ammonia and lactate, respectively). Plasma L-citrulline increased significantly during exercise only after L-ARG load, despite a concomitant decrease in plasma L-ARG. Furthermore, a significant inverse relationship was observed between changes in lactate and L-citrulline concentrations after L-ARG load (r = -0.84, p = 0.009). These results demonstrate that intravenous L-ARG reduces significantly exercise-induced increase in plasma lactate and ammonia. Taken together, the specific L-citrulline increase and the inverse relationship observed between L-citrulline and plasma lactate after L-ARG might support that L-ARG supplementation enhances the L-arginine-nitric oxide (NO) pathway during exercise.:up:Fysiologisk effekt av koffein men även extra psykologisk effekt när försökspersonerna informerats om koffeinets egenskaper.
T.o.m. information+placebo gav bra resultat, placebon höjde alltså deras prestationsförmåga trots att det var koffeinfritt men man förväntade sig effekt iom att man hört om hur bra det är.Quote:Abstract:
The ergogenic effects of caffeine are well documented. Research has yet to examine any psychological contribution to this effect.Aim: To explore the psychological and pharmacological effects of caffeine in laboratory cycling performance.
Method: Fourteen male competitive cyclists performed 14 40-km time trials (eight experimental interspersed with six baseline). The experimental phase consisted of two trials for each of four experimental conditions: informed caffeine/received caffeine, informed no treatment/received caffeine, informed caffeine/received placebo, and informed no treatment/received no treatment. Conditions were nonrandomized. ANOVA was used to estimate main effects and interactions for mean values of power, heart rate, blood lactate, and maximal oxygen uptake. Probabilistic inferences for mean power were based on a smallest worthwhile change of 1.5%.
Results: Relative to baseline, a very likely beneficial main effect of receiving caffeine (3.5%; 95% confidence interval 1.5 to 5.5%), and a possibly beneficial main effect of being informed of caffeine (0.7%; -0.7 to 2.1%) were observed. A substantial interaction between belief and pharmacology indicated that caffeine exerted a greater effect on performance in conditions when subjects were informed that they had not ingested it, whereas belief exerted a greater influence on performance in the absence of caffeine (2.6%; -0.7 to 5.9%). A possibly harmful negative placebo (nocebo) effect was observed when subjects were correctly informed that they had ingested no caffeine (-1.9%; -4.1 to 0.3%). No clinically significant changes relative to baseline were observed in mean heart rate. Clear and substantial increases in blood lactate were evident after receipt of caffeine. Data for mean oxygen uptake were unclear.
Conclusion: Our data support the ergogenic efficacy of caffeine but suggest that both positive and negative expectations impact performance.
Pharmacological and Psychological Effects of Caffeine Ingestion in 40-km Cycling Performance. Medicine & Science in Sports & Exercise. 40(1):158-165, January 2008.
[http://www.ms-se.com/pt/re/msse/abstract.00005768-200801000-00022.htm;jsessionid=HSxCKhy2Y7XMhJcgjQYyGn2RbppGSj8bm4QThPZBs99k1SwxPvd1!2092430889!181195628!8091!-1]
Den här studien visade att Beta Alanin förbättrade uthålligheten under styrketräning.
Men för 400 m löpare var det ingen markant effekt vid oralt intagande av Beta alanin.
Ni som inte tagit Beta-alanin förvarnas att hela kroppen kliar och man känner irriterande stickningar i hela kroppen.beta-Alanine supplementation augments muscle carnosine content and attenuates fatigue during repeated isokinetic contraction bouts in trained sprinters.
Derave W, Ozdemir MS, Harris RC, Pottier A, Reyngoudt H, Koppo K, Wise JA, Achten E.
Dept. of Movement and Sport Sciences, Ghent Univ., Watersportlaan 2, B-9000 Ghent, Belgium. [mailto:Wim.derave@ugent.be]Carnosine (beta-alanyl-l-histidine) is present in high concentrations in human skeletal muscle. The ingestion of beta-alanine, the rate-limiting precursor of carnosine, has been shown to elevate the muscle carnosine content. We aimed to investigate, using proton magnetic resonance spectroscopy (proton MRS), whether oral supplementation with beta-alanine during 4 wk would elevate the calf muscle carnosine content and affect exercise performance in 400-m sprint-trained competitive athletes. Fifteen male athletes participated in a placebo-controlled, double-blind study and were supplemented orally for 4 wk with either 4.8 g/day beta-alanine or placebo. Muscle carnosine concentration was quantified in soleus and gastrocnemius by proton MRS. Performance was evaluated by isokinetic testing during five bouts of 30 maximal voluntary knee extensions, by endurance during isometric contraction at 45% maximal voluntary contraction, and by the indoor 400-m running time. beta-Alanine supplementation significantly increased the carnosine content in both the soleus (+47%) and gastrocnemius (+37%). In placebo, carnosine remained stable in soleus, while a small and significant increase of +16% occurred in gastrocnemius. Dynamic knee extension torque during the fourth and fifth bout was significantly improved with beta-alanine but not with placebo. Isometric endurance and 400-m race time were not affected by treatment. In conclusion, 1) proton MRS can be used to noninvasively quantify human muscle carnosine content; 2) muscle carnosine is increased by oral beta-alanine supplementation in sprint-trained athletes; 3) carnosine loading slightly but significantly attenuated fatigue in repeated bouts of exhaustive dynamic contractions; and 4) the increase in muscle carnosine did not improve isometric endurance or 400-m race time.
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