- 06-15-2006, 11:25 PM
1: Life Sci. 2006 Apr 22; [Epub ahead of print] Related Articles, Links
Effect of chronic supplementation with branched-chain amino acids on the performance and hepatic and muscle glycogen content in trained rats.
de Araujo JA Jr, Falavigna G, Rogero MM, Pires IS, Pedrosa RG, Castro IA, Donato J Jr, Tirapegui J.
Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, Brazil.
The objective of this study was to evaluate the effects of a diet supplemented with branched-chain amino acids (BCAA; 3.57% and 4.76%) on the performance and glycogen metabolism of trained rats. Thirty-six adult male Wistar rats received the control diet (AIN-93M) (n=12) and two diets supplemented with BCAA (S1: AIN-93M+3.57% BCAA, n=12, and S2: AIN-93M+4.76% BCAA, n=12) for 6 weeks. The training protocol consisted of bouts of swimming exercise (60 min day(-1)) for 6 weeks at intensities close to the lactate threshold. On the last day of the experiment, all groups were trained for 1 h (1H) or were submitted to the exhaustion test (EX). The time to exhaustion did not differ between groups. The groups submitted to the exhaustion test presented a reduction in plasma glucose and an increase in plasma ammonia and blood lactate concentrations compared to the 1H condition. In the 1H condition, hepatic glycogen concentration was significantly higher in group S2 compared to the control diet and S1 groups (132% and 44%, respectively). Group S2 in the 1H condition presented a higher muscle glycogen concentration (45%) compared to the control diet group. In the EX condition, a significantly higher hepatic glycogen concentration was observed for group S2 compared to the control diet and S1 groups (262% and 222%, respectively). Chronic supplementation with BCAA promoted a higher hepatic and muscle glycogen concentration in trained animals, with this effect being dose dependent.
PMID: 16698042 [PubMed - as supplied by publisher]
J Nutr. 2006 Feb;136(2):544S-547S. Related Articles, Links
A role for branched-chain amino acids in reducing central fatigue.
Astrand Laboratory, University College of Physical Education and Sports and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden. [email protected]
Several factors have been identified to cause peripheral fatigue during exercise, whereas the mechanisms behind central fatigue are less well known. Changes in the brain 5-hydroxytryptamine (5-HT) level is one factor that has been suggested to cause fatigue. The rate-limiting step in the synthesis of 5-HT is the transport of tryptophan across the blood-brain barrier. This transport is influenced by the fraction of tryptophan available for transport into the brain and the concentration of the other large neutral amino acids, including the BCAAs (leucine, isoleucine, and valine), which are transported via the same carrier system. Studies in human subjects have shown that the plasma ratio of free tryptophan (unbound to albumin)/BCAAs increases and that tryptophan is taken up by the brain during endurance exercise, suggesting that this may increase the synthesis of 5-HT in the brain. Ingestion of BCAAs increases their concentration in plasma. This may reduce the uptake of tryptophan by the brain and also 5-HT synthesis and thereby delay fatigue. Accordingly, when BCAAs were supplied to human subjects during a standardized cycle ergometer exercise their ratings of perceived exertion and mental fatigue were reduced, and, during a competitive 30-km cross-country race, their performance on different cognitive tests was improved after the race. In some situations the intake of BCAAs also improves physical performance. The results also suggest that ingestion of carbohydrates during exercise delays a possible effect of BCAAs on fatigue since the brain's uptake of tryptophan is reduced.
J Nutr. 2006 Feb;136(2):538S-543S. Related Articles, Links
Amino acid mixture improves training efficiency in athletes.
Ohtani M, Sugita M, Maruyama K.
Department of Environmental Studies, Graduate School of Frontier Sciences, the University of Tokyo, Chiba, Japan. [email protected]
This review discusses some of the beneficial effects of a dietary amino acid supplement on muscle function, fatigue, and recovery in exercising athletes. The supplement, a mixture of amino acids that included the branched-chain amino acids, arginine and glutamine, was studied chronically at several daily dose levels for extended periods of time (10, 30, and 90 d). Outcome variables included physical measures of muscle strength, fatigue and damage, and blood indices of muscle damage and oxygen-carrying capacity. One beneficial effect of the amino acid supplement was a quicker recovery from the muscle fatigue that followed eccentric exercise training. A dose-response study of the amino acid mixture at 2.2, 4.4, and 6.6 g/d for 1 mo showed that at the highest dose, indices of blood oxygen-carrying capacity were increased and those of muscle damage were decreased at the end of the trial. When the amino acid mixture was given for 90 d to elite rugby players during training at a dose of 7.2 g/d, a blood-component analysis indicated improvements in the oxygen-carrying capacity of the blood. Together, the studies suggest that the amino acid supplement contributed to an improvement in training efficiency through positive effects on muscle integrity and hematopoiesis.
1: J Nutr. 2006 Feb;136(2):533S-537S. Related Articles, Links
Leucine regulates translation initiation of protein synthesis in skeletal muscle after exercise.
Norton LE, Layman DK.
Division of Nutritional Sciences, Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
High-performance physical activity and postexercise recovery lead to significant changes in amino acid and protein metabolism in skeletal muscle. Central to these changes is an increase in the metabolism of the BCAA leucine. During exercise, muscle protein synthesis decreases together with a net increase in protein degradation and stimulation of BCAA oxidation. The decrease in protein synthesis is associated with inhibition of translation initiation factors 4E and 4G and ribosomal protein S6 under regulatory controls of intracellular insulin signaling and leucine concentrations. BCAA oxidation increases through activation of the branched-chain alpha-keto acid dehydrogenase (BCKDH). BCKDH activity increases with exercise, reducing plasma and intracellular leucine concentrations. After exercise, recovery of muscle protein synthesis requires dietary protein or BCAA to increase tissue levels of leucine in order to release the inhibition of the initiation factor 4 complex through activation of the protein kinase mammalian target of rapamycin (mTOR). Leucine's effect on mTOR is synergistic with insulin via the phosphoinositol 3-kinase signaling pathway. Together, insulin and leucine allow skeletal muscle to coordinate protein synthesis with physiological state and dietary intake.
1: J Nutr. 2006 Jan;136(1 Suppl):274S-6S. Related Articles, Links
Branched-chain amino acids and central fatigue.
Newsholme EA, Blomstrand E.
Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden. [email protected]
An account of the tryptophan (Trp)-5-hydroxytryptamine (5-HT)-central fatigue theory is provided and an explanation of how oral administration of BCAAs can decrease fatigue on the basis of this theory is given. The rate-limiting step in the synthesis of 5-HT is the transport of Trp across the blood-brain barrier. This transport is influenced by the fraction of Trp available for transport into the brain and the concentration of the other large neutral amino acids, including the BCAAs, which are transported via the same carrier system. During endurance exercise, there is an uptake of Trp by the brain, suggesting that this may increase the synthesis and release of 5-HT in the brain. Oral intake of BCAAs may reduce this uptake and also brain 5-HT synthesis and release, thereby delaying fatigue. Other hypotheses for the effect of BCAAs on central fatigue are included.
PMID: 16365097 [PubMed - indexed for MEDLINE]
- 06-18-2006, 02:37 AM
Yes, this is true, however, don't take your BCAA's during workout with carbohydrates. Insulin causes your body to switch to glycogen as its main source of fuel as opposed to fat.PharmD
06-18-2006, 03:22 AM
Why is this really such a big deal when training? Does relying on fat as the source of fuel during intense exercise really make that much of a difference in terms of leanness, in the grand scheme of things? I gathered that it was more important to worry about burning fat during times of rest than it was during exercise, as the body prefers glucose as it's fuel source when working out.Originally Posted by LakeMountD
I'm not really following along with your reasoning on this issue, as it flies in the face of most of the information I've seen with regards to maximal exercise performance and recovery. I suppose if one were on a ketogenic diet then things would be different though.
06-21-2006, 10:39 PM
so is this saying we shouldn't sip our Excell during workouts, cause I have been and just recently added a carb rich PWO after each workout?
06-22-2006, 09:38 PM
It depends on your goals.
If your goals are for fat loss - the best bet is to not have carbs in that during WO shake. (The amino acids will be burned as glucose anyway...)
Max - I would think it could make a difference. If you are after performace (I.E. PR's) - then yes, have the carbs/aminos during a workout.
06-22-2006, 10:02 PM
Originally Posted by wrkn4bigrmusles
BCAA's without carbs during w/o is fine.
Carbs in your PWO shake is fine.
That's the way I've been doing it for months also
06-22-2006, 10:07 PM
06-22-2006, 10:15 PM
06-22-2006, 10:28 PM
Am J Physiol Endocrinol Metab 281: E365-E374, 2001;
BCAA intake affects protein metabolism in muscle after but not during exercise in humans
Eva Blomstrand and Bengt Saltin
Copenhagen Muscle Research Centre, Rigshospitalet, DK-2200 Copenhagen N, Denmark
...................The results suggest that BCAA have a protein-sparing effect during the recovery after exercise, either that protein synthesis has been stimulated and/or protein degradation has decreased, but the data during exercise are too variable to make any conclusions about the effects during exercise. The effect in the recovery period does not seem to be mediated by insulin.
06-22-2006, 10:44 PM
1: Am J Physiol. 1994 Dec;267(6 Pt 1):E1010-22. Related Articles, Links
Branched-chain amino acids augment ammonia metabolism while attenuating protein breakdown during exercise.
MacLean DA, Graham TE, Saltin B.
School of Human Biology, University of Guelph, Ontario, Canada.
In this study, five men exercised the knee extensor muscles of one leg for 60 min (71 +/- 2% maximal work capacity) with and without (control) an oral supplement (77 mg/kg) of branched-chain amino acids (BCAA). BCAA supplementation resulted in a doubling (P < 0.05) of the arterial BCAA levels before exercise (339 +/- 15 vs. 822 +/- 86 microM). During the 60 min of exercise, the total release of BCAA was 68 +/- 93 vs. 816 +/- 198 mumol/kg (P < 0.05) for the BCAA and control trials, respectively. The intramuscular BCAA concentrations were higher (P < 0.05) for the BCAA trial and remained higher (P < 0.05) throughout exercise. In both trials, substantial quantities of NH3 were released, and when NH3 production equivalent to IMP accumulation was subtracted the net NH3 production was 1,112 +/- 279 and 1,670 +/- 245 mumol/kg (P < 0.05) for the control and BCAA trials, respectively. In contrast, the release of the essential amino acids (EAA) was much lower for the BCAA than the control trial (P < 0.05). When the BCAA were subtracted from the EAA (EAA-BCAA), the total release of EAA minus BCAA was lower (P < 0.05) for the BCAA (531 +/- 70 mumol/kg) than the control (924 +/- 148 mumol/kg) trial. These data suggest that BCAA supplementation results in significantly greater muscle NH3 production during exercise. Furthermore, the increased intramuscular and arterial BCAA levels before and during exercise result in a suppression of endogenous muscle protein breakdown during exercise.
06-23-2006, 12:30 PM
Adding BCAA supplementation has been the single best supp I have ever added - along with creatine it's the biggest assistant to dieting while making you feel like you are bulking.
****EXCELL LOG ****Pfunk47
That's a two month long log of mega-dosing - I am extrememly pleased with the results.
06-23-2006, 12:39 PM
I've been using BCAA's as well while dieting, and ingest 20 grams of supercarb starting 15 minutes pre-workout, sipped throughout, and finished off at the end of the workout. That's been working like a charm for myself, as I've still easily lost 1-1.5 pounds per week, and gained strength in many exercises, while at least maintaining strength in all exercises.
06-23-2006, 01:13 PM
I read the log (as you know) and I am convinced enough to give them a try. I am just wondering when the best time to dose is... there are conflicting reports as to whether 'sipping throughtout workout' (as is the common method of administration) is as effective as pre/post workout consumption.Originally Posted by Pfunk47
06-23-2006, 01:33 PM
I think if you started sipping about 30 min before your workout - you'd have great energy throughout your workout - I think the benefits of mega-dosing is having a costant influx of Aminos into your cells - helping you heal/build and spare protein. When dieting is over - I plan to try a month doing it just 3 througout workout - then do another month of 3 throughout the day, none during worout to try and help people out with dosing protocols that give you the most affect.
06-28-2006, 12:04 AM
J Am Coll Nutr. 2006 Jun;25(3):188-94. Related Articles, Links
Influence of branched-chain amino acid supplementation on urinary protein metabolite concentrations after swimming.
Graduate Institute of Nutritional Sciences and Education, National Taiwan Normal University, Taipei, Taiwan, ROC. [email protected]
OBJECTIVE: The influence of branched-chain amino acid (BCAA) supplementation on urinary urea nitrogen, hydroxyproline (HP), and 3-methylhistidine (3MH) concentrations after 25 min of breast stroke exercise (65-70% maximum heart rate reserved, 65-70% HRRmax) followed by a 600 m crawl stroke competition was investigated in a double-blind, counter-balanced study. METHODS: Male university students (19-22 years old) majoring in physical education participated in the study. Based on the previous swimming time of a 600 m crawl stroke, the participants were divided into two groups: placebo (n = 9, BMI = 24.2 +/- 2.1 kg/m2; 12 g of glucose/day; in capsules) and BCAA (n = 10, BMI = 22.7 +/- 1.5 kg/m2; 12 g of BCAAs/day; in capsules: leucine 54%, isoleucine 19%, valine 27%) groups. The participants maintained a regular dietary intake (except the prescribed breakfast on day 15) and exercise activity at a moderate/low intensity (60-70% HRRmax, swimming and rowing, approximately 1.5 hour/day) during the 15-day study. A prescribed exercise program was performed on day 15. Urinary and blood samples were collected before, during, and after the prescribed exercise for the measurements of the urinary urea nitrogen, HP, and 3MH concentrations in urine, as well as the glucose, lactate, glutamine, alanine, and BCAA concentrations in plasma. RESULTS: Two weeks of dietary supplementation did not induce any changes in the plasma glucose and total BCAA concentrations of either group, nor in the urinary urea nitrogen, HP, and 3MH concentrations in urine. On day 15, after 25 min of breast stroke exercise and a 600 m crawl stroke competition, plasma glucose concentration decreased significantly (p < 0.05) whereas plasma lactate concentration increased significantly (p < 0.05) in both groups. The exercise program prescribed in the study did not affect urinary urea nitrogen, HP, and 3MH concentrations. Twenty hours after the competition, however, a significant increase in the concentrations of urinary urea nitrogen, HP, and 3MH was found in the placebo group (p < 0.05), but not in the BCAA group. CONCLUSIONS: The results obtained in this study suggest that swimming induced muscle proteolysis was prevented by BCAA supplementation. The mechanism could be attributed to the availability of ammonia provided by the oxidation of supplemented BCAAs during exercise.
06-28-2006, 12:31 AM
The first study you posted, however, can be said to be moot in this case since any protein powder you use PWO will give you the necessary BCAA's. The second study you posted was one I posted a while back and that shows the significance of BCAA's during workout WITHOUT CARBS. I have always suggested consuming them during workout and let your protein powder handle it PWO.
06-28-2006, 12:45 AM
While I agree with you, this being a scientific study, such comments must be confined to the discussion portion of the article. You cannot experiment with BCAAs then make a conclusion about protein powder; there are several variables that would come into play.Originally Posted by LakeMountD
In any event, I am really looking forward to giving excel a try... I think there is more than convincing evidence that BCAA supplementation aids in preventing/delaying fatigue during exercise, and limiting muscle breakdown during exercise.
06-28-2006, 12:59 AM
During weight training, most of the energy you use is going to come from muscle glycogen anyway so by adding CHO to your during workout shake would only provide more energy. You cannot 'rely' on fat burning during any intense exercise as it will only contribute a small amount to the energy being burned.Originally Posted by max silver
06-28-2006, 01:19 AM
I don't think there has been enough research done on BCAA supplementation done during exercise. I think we should go by anecdotal results and it seems that supplementation during exercise is the way to go. Consuming BCAAs prior to exercise would also be a good idea because it would be offered as an additional energy substrate and spare muscle glycogen. I would assume that this would also occur if you consumed during exercise. Most of the studies done on BCAA supp. during exercise (as represented by some of the first studies in this post) focus on the positive effects related to mood and perceived fatigue as a result of changes in neurotransmitter levels in the brain.
06-28-2006, 09:06 AM
Originally Posted by canadian champ
You actually can, considering the fact that any decen protein powder is loaded with BCAA's. I am not saying drink protein powder during exercise since not all of the protein is BCAA and there are other carbs and fillers in there but during exercise, in my opinion based off all the studies I have read in the past, is the most logical route to go since your PWO protein does contain such a large amount of them.
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