How long per serving of BCAA would prevent catabolism for?
BCAAs don't exactly have any specified longevity, per se. at least that i know of. obviously, i'd assume that the more you drink at any given time the longer they'd stay active within your system. it depends on the serving size.
found this article off another bodybuilding forum. i thought it was an interesting read, especially the last few lines...
*originally posted by In-Human on oldschoolbodybuilding.com*
The branched-chain amino acids (BCAAs) are leucine, isoleucine, and valine. BCAAs are considered essential amino acids because human beings cannot survive unless these amino acids are present in the diet.
BCAAs are needed for the maintenance of muscle tissue and appear to preserve muscle stores of glycogen (a storage form of carbohydrate that can be converted into energy).1 BCAAs also help prevent muscle protein breakdown during exercise.2
Some research has shown that BCAA supplementation (typically 10-20 grams per day) does not result in meaningful changes in body composition,3 nor does it improve exercise performance4 5 6 7 8 or enhance the effects of physical training.9 10 However, BCAA supplementation may be useful in special situations, such as preventing muscle loss at high altitudes11 and prolonging endurance performance in the heat.12 Studies by one group of researchers suggest that BCAA supplementation may also improve exercise-induced declines in some aspects of mental functioning.13 14 15
BCAAs can active glutamate dehydrogenase—an enzyme that is deficient in amyotrophic lateral sclerosis (ALS), also called Lou Gehrig’s disease. In one double-blind trial, 26 grams per day of BCAA supplements helped those with ALS maintain muscle strength.16 However, a larger study was ended early when people using BCAAs not only failed to improve, but experienced higher death rates than the placebo group.17 Other studies have shown no benefit of BCAA supplementation for ALS or other neuromuscular diseases,18 19 though a small group of people suffering from diseases of the nervous system collectively called spinocerebellar degeneration did improve when given BCAAs in a preliminary study.20
One study investigating the advantages of BCAA supplementation for people with diabetes undergoing an intense exercise program found no additional benefit of BCAAs on reducing abdominal fat or improving glucose metabolism.21
Patients with liver diseases that lead to coma—called hepatic encephalopathy—have low concentrations of BCAAs and excess levels of certain other amino acids. Preliminary research suggested that people with this condition might be helped by BCAAs. Double-blind studies have produced somewhat inconsistent results,22 23 24 but a reanalysis of these studies found an overall benefit for the symptoms of encephalopathy.25 Therapeutic effects of BCAAs have also been shown in children with liver failure26 and adults with cirrhosis of the liver.27 Any treatment of people with liver failure requires the direction of a physician.
People with chronic kidney failure may also benefit from BCAA supplementation. A preliminary study found improved breathing and sleep quality in people given intravenous BCAAs during kidney dialysis.28
Phenylketonuria (PKU) is a genetic disease that causes abnormally high amounts of phenylalanine and its end products to accumulate in the blood, causing damage to the nervous system. A controlled trial demonstrated that regular use of BCAAs by adolescents and young adults with PKU, improved performance on some tests of mental functioning.29 This outcome makes sense because BCAAs may compete with phenylalanine, reducing its toxic effects.
In tardive dyskinesia, phenylalanine levels have also been reported to be elevated. As a result, one group of researchers gave tardive dyskinesia patients BCAAs (from 150 mg per 2.2 pounds body weight up to 209 mg per 2.2 pounds body weight) after breakfast and one hour before lunch and dinner for two weeks.30 The BCAA mixture included equal parts valine and isoleucine plus 33% more leucine than either of the other two amino acids. Of nine patients so treated, six had at least a 58% decrease in symptoms, and all people in the study had a decrease of at least 38% in symptoms.
Where are they found?
Dairy products and red meat contain the greatest amounts of BCAAs, although they are present in all protein-containing foods. Whey protein and egg protein supplements are other sources of BCAAs. BCAA supplements provide the amino acids leucine, isoleucine, and valine...
Branched-chain amino acid (BCAA) supplements are all the rage with endurance athletes these days. One popular idea is that the three BCMs - valine, leucine, and isoleucine - can move through the blood to the brain and decrease the production of serotonin in the brain's interior, thereby lowering mental fatigue (serotonin can create a sense of tiredness - see previous story). A fairly limited amount of scientific research supports this hypothesis.
However, new studies carried out at the University of Limburg in the Netherlands cast doubt on an ergogenic role for BCMs. At Limburg, 10 subjects cycled until exhaustion at 70-75 per cent of maximal power output while ingesting sugary sports drinks. On one occasion, nothing had been added to the beverage, but during other trials the drink was laced with either a small amount of BCAAs, a large quantity of BCAAs, or a modest amount of 'L-tryptophan,' an amino acid which is used to synthesise serotonin.
Ingestion of tryptophan boosted blood levels of the chemical by 500 per cent, and consumption of ample amounts of BCAAs quintupled BCM-blood concentrations, but neither supplement had any effect on performance; time to exhaustion averaged about 120 minutes on all four trials. The researchers concluded that supplementation with BCAAs does not improve endurance during exertions lasting about two hours.
A second study confirmed the idea that BCAAs have little impact on endurance. At the University of Cape Town, eight endurance-trained cyclists pedaled away for four hours in the laboratory at 55% V02max (70 per cent of maximal heart rate) and then tried to cover a 40-kilometre distance as quickly as possible. On separate occasions, the cyclists sipped a 10-per cent carbohydrate sports drink, a 10-per cent drink with BCMs, or a beverage with BCMs alone as they exercised.
Use of the BCAAs didn't help the athletes at all; time for the 40-K trial averaged about 68 minutes, regardless of whether BCMs were ingested, and perceived exertion (how the effort actually felt) was the same in all three trials. The South African researchers concluded that BCAAs might be slightly helpful but that physical fatigue overrode any possible mental relief provided by the BCAA supplementation.
However, a final study carried out at the University of Guelph in Canada detected a possibly positive role for BCAAs. At Guelph, subjects completed two trials in which they exercised their quadriceps muscles continuously for 60 minutes. Prior to only one of the trials, the athletes ingested 77 mg of BCAAs per kilogram of body weight (about a five-gram dose for a 154-pound individual).
As a result of the pre-workout BCAA supplementation, degradation of proteins inside the quadriceps muscles was considerably reduced during exercise. This is a potentially positive effect, since proteins broken down during exercise must be replaced before subsequent workouts so that an athlete can continue training at a high level. In other words, BCM intake before exercise may lead to a lower requirement for muscle repair after a workout - and a quicker recovery from a strenuous exertion.
In previous studies carried out over the last year or so, BCAA supplementation has been linked with better immune-system functioning and superior preservation of muscle mass in athletes undergoing heavy training. Therefore, although an acute dose of BCAAs probably won't directly boost endurance during a competitive event, it's tempting to speculate that taking in three to five grams of BCAAs before and after strenuous workouts might produce some beneficial long-term effects in serious endurance athletes...