03-07-2005, 02:13 PM #1
Supplement Analysis: Nitric Oxide, BCAA’s, and Tribulus Terastris
This is a good read fellas:
Nitric Oxide Hemodilators
Nitric oxide supplements are the hottest thing on the market. Athletes are buying them in droves without knowing exactly what is happening in the body. Supplement companies claim to educate their consumers with pamphlets and informational websites, but these only offer an incomplete story of what is actually happening. Manufacturers state that nitric oxide supplements, via the compound arginine alpha-ketoglutarate, gives the athlete added energy, mental focus, workout intensity, perpetual pump and muscle growth. Upon closer investigation, these effects are largely exaggerated and in some cases completely fallacious. While arginine is involved in the regulation of growth hormone release, the supplemental dosages that would stimulate a noticeable effect are astronomical. Arginine is also a substrate for nitric oxide; an effect that is enhanced when combined with alpha-ketoglutarate. Nitric oxide is released by the walls of the blood vessels that cause a decrease in the resistance and an increase in blood flow to the skeletal muscles. Arginine may also stimulate the release of epinephrine from the adrenal gland. These two effects are mostly beneficial to endurance athletes, not strength athletes like the manufacturers suggest. Grasemann et al. (2005) determined that participants receiving as little as 200 mg of L-arginine showed a significant increase in nitric oxide formation, as well as significant increases in plasma L-arginine and sputum L-arginine. This indicates that L-arginine supplementation does indeed induce nitric oxide formation. Rytlewski et al. (2005) found that three weeks of L-arginine supplementation lead to significant drops in systolic blood pressure, diastolic blood pressure, and mean arteriole pressure while elevating urinary excretion of NOx (nitrates) and mean plasma levels of l-citrulline. However, plasma L-arginine levels were not effected even with 300 mg of supplementation. Thusfar it has been established that L-arginine supplementation does indeed stimulate nitric oxide synthesis. Now it must be addressed whether or not this is beneficial to athletes.
Paddon-Jones et al. (2004) found that nitric oxide supplementation does not provide an ergogenic effect to healthy individuals. Miguez et al. (2004) found that 4 weeks of L-arginine supplementation increased serum triglyceride levels and significantly increased levels of low-density lipoprotein (LD) cholesterol. This is obviously cause for concern and needs to be further investigated. Evans et al. (2004) sought to find the optimal dosage of L-arginine to elicit the greatest effect on nitric oxide synthesis. Manufacturers recommend upwards of 6000-10000 mg/day but many athletes report taking even higher dosages as much as 35000 mg/day, nearly six times the recommended intake. Evans (2004) found that half the participants supplementing with 20000 mg/day reported serious adverse side effects from L-arginine supplementation and over half of the participants reported severe side effects when taking more than 20000 mg/day. A significant portion of individuals supplementing with 9000 mg/day reported adverse effects, and over the duration of the supplementation period, no participants experienced any sort of weight gain. Chu et al. (2004) found that L-arginine supplementation impaired pulmonary endothelium-dependent relaxation of vascular tissue. This may lead to potentially dangerous vascular spasms and cardiovascular abnormalities.
It has been found that L-arginine keto-gluterate supplementation stimulates rapid vasidilation in a non-discriminatory fashion. Significant vasodilatation causes a drop in blood pressure (because as the veins widen, the pressure drops). Baroreceptors in the aortic arch and in the carotid sinus will detect this fast, significant drop in both systolic and diastolic blood pressure. During exercise, it is imperative that diastolic blood pressure remain constant. It is natural for systolic blood pressure to rise during the onset of exercise, but diastolic blood pressure values must remain constant. A drop in either during exercise is cause for great concern and can lead to serious cardiovascular damage. In order to protect the body from going into shock, vasomotor centers in the medulla will cause the blood vessels leading to the brain to constrict in order to increase blood pressure going into the brain (too much blood can severely damage the brain, just like too little). This is a dangerous sequence that can potentially lead to a vascular catastrophe.
Based on the available research, this author strongly recommends that athletes avoid nitric oxide and hemodilator supplements in the interest of safety. Moreover, it has been suggested that these supplements have little or no anabolic or ergogenic benefits for the athlete
Branched Chain Amino Acids (BCAA): L-Leucine, L-Isoleucine, L-Valine
The three branched chain amino acids consist of L-leucine, L-isoleucine, and L-valine. They are called BCAAs because of their unique molecular arrangement, which consists of methyl side chains (CH3) coming out of the amino acid nucleus. The body cannot manufacture them; therefore they are also considered essential amino acids. It has been shown that BCAA supplementation spares muscle tissue under stress (as in a pre-contest diet). BCAAs may also boost anabolism, as they are oxidized during intense exercise. BCAAs are the fastest absorbed amino acids. It has been suggested that as much as 70% of all amino acids processed by the liver and released into the bloodstream are BCAAs. Once in the blood, BCAAs are rapidly absorbed by skeletal muscle tissue. Once inside, BCAAs begin to facilitate the synthesis of more amino acids, causing an added anabolic effect. It has also been found that L-leucine indirectly stimulates insulin production.
For the optimal benefit, the three amino acids should be taken together to ensure maximum absorption. The standard dosage is 500 to 3000 mg/day of each. However dosages as high as 10 grams have been shown to benefit athletes as well. To further ensure absorption, 50 to 100 milligrams of vitamin B6 should be taken daily. The optimal time for BCAA supplementation is in the post workout meal (note: not the post workout shake!). It should be noted, however, that BCAAs actively compete for absorption with tryptophan and tyrosine, therefore they should not be supplemented at the same time.
BCAAs enhance exercise performance in a variety of ways. They could be used as a direct fuel source during prolonged exercise thus preventing changes in neurotransmitter function, sparing muscle glycogen, and decreasing protein degradation. Most of the research concerning branched chain amino acids has surrounded a phenomenon called the Central Fatigue Hypothesis. First proposed by Dr. Newsholme, a professor at Oxford University, the Central Fatigue Hypothesis postulates that high levels of serum free-tryptophan (fTRP) in conjunction with low levels of BCAAs may be the major factor in the etiology of fatigue during prolonged endurance exercise. A high fTRP:BCAA ratio may lead to an increased production of serotonin. The utilization of BCAAs for energy during endurance exercise increases this ratio causing an increase uptake and utilization of tryptophan by the brain thereby increasing serum serotonin levels. Fatigue seems to be associated with increases in brain serotonin, as well as other neurotransmitters such as dopamine. With BCAA supplementation, a stable ratio of fTRP:BCAA may be maintained, thereby delaying the onset of fatigue during prolonged endurance exercise. It is known that BCAAs are primarily metabolized in skeletal muscle tissue.
Blomstrand et al. (1997) BCAA supplementation, in direct correlation to an increased fTRP:BCAA ratio may improve mental performance as well as physical performance. Further, BCAA supplementation has been shown to reduce the RPE (rating of perceived exertion) of endurance athletes and reduced mental fatigue. Mittleman et al. (1998) reported an increase of 12% in cycle time to exhaustion at 40% VO2peak with BCAA supplementation. Plasma BCAA levels were elevated, but cardiovascular, thermoregulatory, and psychological data were unchanged when compared to the placebo condition. BCAA supplementation has been theorized to have positive effects on body composition and has been associated with decrease muscle protein breakdown during exercise. Williams (1999) cited evidence that BCAA supplementation, in conjunction with a calorie restricted diet (as in a pre-contest diet) was more effective than three other diets geared towards losing body fat and preserving muscle mass.
Supplementing with branched chain amino acids has been shown to be safe and effective, although supplementing in high amounts has been shown to cause slight gastrointestinal distress. As noted earlier, BCAAs compete with tryptophan and tyrosine. It is imperative that these two amino acids are taken apart from BCAAs as a deficiency in them may lead to nervous system dysfunctions. Tryptophan and tyrosine are precursors for neurotransmitters, therefore they are essential for the maintenance of the central nervous system. However deficiencies are very rare.
In conclusion, it is the opinion of this author, based on available research, that branched chain amino acid supplementation is beneficial to the athlete, especially during a pre-contest diet.
Tribulus terrestris is a prostrate, matforming plant. Although it has been used by the Chinese for thousands of years, little was scientifically known about it until recently. Tribulus is said to increase testosterone levels by as much as 30%, especially when taken in conjunction with sopharma. The primary mechanism of action to explain this phenomenon is that tribulus stimulates the secretion of lutenizing hormone (LH) from the anterior pituitary gland. This in turn stimulates testosterone production, as well as growth hormone and estradiol. Therefore, tribulus can easily stimulate gynecomastia (gyno) and insulin resistance. This is very negative for bodybuilders. In women, tribulus stimulates follicle-stimulating hormone (FSH) and estradiol, but not testosterone. 750-1200 mg/day dosages are not uncommon and is usually stacked with 100 mg/day of DHEA (discussed later) and 100 mg/day of androstenedione. Although the rise in testosterone levels may sound attractive to many athletes, the side effects are much more dire than gynecomastia and insulin resistance. Tribulus Terrestris has been shown to dilate the coronary arteries (Wang, 1990) and has a diuretic effect (Arcasoy, 1998). In both cases, this can put the athlete in a dangerous state. Bourke (1995) found that severe nervous and muscular locomotor disorders are directly associated with tribulus terrestris ingestion. The production of bile stones is also greatly enhanced (Miles, 1994) due to hyperplasia of the bile ducts and diffuse swelling of hepatocytes (Tapia, 1994).
Gauthaman et al. (2005) suggests that tribulus stimulates androgen production, an effect similar to that of prohormones and prosteroids. As noted above, tribulus increases the risk of developing gynecomastia. Jameel et al. (2004) confirms this by stating that the increased incidence of gynecomastia in young male athletes is a direct result of the increased use of steroids and tribulus terrestris. Other evidence suggests that the heavy diuretic effect of tribulus can cause kidney damage.
Tribulus also contains a compound called saponin, which is a class of glucosides. Saponin derived from tribulus has been shown by Li et al. (2002) to elicit a hypoglycemic effect. Serum glucose is significantly lowered with tribulus supplementation, which has negative effects on insulin sensitivity and central nervous system function (the CNS runs solely on blood glucose). A result of prolonged tribulus supplementation may be diabetes. Further investigations by the same researchers found that tribulus lowers plasma HDL (“good” cholesterol) levels and severely restricts gluconeogenesis activity in the liver. Antonio et al. (2000) assessed the effect of tribulus supplementation (in high doses) on trained male athletes. Over the course of the investigation, there were no changes in body weight, percentage fat, total body water, dietary intake, or mood states in either group. Slight increases in muscle strength were found in the tribulus group compared to the placebo, but the results were not significant. Antonio and his associates concluded: “Supplementation with tribulus does not enhance body composition or exercise performance in resistance-trained males.”
Based on the available evidence, tribulus terrestris is an extremely dangerous supplement and cannot be used in a safe manner. Its supplementation should be avoided by all athletes at all times.
Conclusions and Recommendations
Based on current scientific research, it would be prudent for athletes to avoid supplementing with arginine alpha-ketogluterate and other hemodilators, as well as tribulus terrestris. Branched Chain Amino Acids, on the other hand, are safe for consumption and have many benefits for athletes.
Keep it Hardcore!
Joe “Yu Yevon” King
Administrator of Hyperplasia Research
Writer for the Journal of Hyperplasia Research
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03-13-2005, 12:49 PM #2Associate Member
- Join Date
- Jan 2003
I don't know if that's such a good read... Its references start with "god/the bible"... That must tell you something!
03-13-2005, 01:51 PM #3King of Supplements
Originally Posted by wilthepill123
- Join Date
- Mar 2004
- east coast
03-13-2005, 01:53 PM #4
Now they are saying how trib is almost as bad as ph's gimmie a break, fuggin tree-huggers.
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