Des méga doses de bétaïne pour prendre du muscle ?

[audiomaniac]

j’en parlais déjà dans le Monde du Muscle. La bétaïne est utilisée depuis des lustres pour faire prendre du muscle aux animaux. Pourquoi n’a t’on pas des suppléments apportant 10 ou 20 g de bétaïne? Effects of betaine on performance and body composition: a review of recent findings and potential mechanisms Jason M. Cholewa Amino Acids August 2014, Volume 46, Issue 8, pp 1785-1793 Betaine is a methyl derivative of glycine first isolated from sugar beets. Betaine consumed from food sources and through dietary supplements presents similar bioavailability and is metabolized to di-methylglycine and sarcosine in the liver. The ergogenic and clinical effects of betaine have been investigated with doses ranging from 500 to 9,000 mg/day. Some studies using animal models and human subjects suggest that betaine supplementation could promote adiposity reductions and/or lean mass gains. Moreover, previous investigations report positive effects of betaine on sports performance in both endurance- and resistance-type exercise, despite some conflicting results. The mechanisms underlying these effects are poorly understood, but could involve the stimulation of lipolysis and inhibition of lipogenesis via gene expression and subsequent activity of lipolytic-/lipogenic-related proteins, stimulation of autocrine/endocrine IGF-1 release and insulin receptor signaling pathways, stimulation of growth hormone secretion, increased creatine synthesis, increases in protein synthesis via intracellular hyper-hydration, as well as exerting psychological effects such as attenuating sensations of fatigue. However, the exact mechanisms behind betaine action and the long-term effects of supplementation on humans remain to be elucidated. This review aims to describe evidence for the use of betaine as an ergogenic and esthetic aid, and discuss the potential mechanisms underlying these effects.

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[audiomaniac]

Best known for its role in taming inflammation, betaine, also known as trimethylglycine, has many other functions in the body. This derivative of the amino acid glycine helps

• protect cells, proteins and enzymes from environmental stress
• maintain normal cell volume
• support liver and heart functioning
• stimulate the body to make both carnitine and creatine

But that’s not all: Now scientists have solid data supporting betaine’s beneficial effects on muscles. When combined with an effective strength-training program, betaine supplementation can give you better results by increasing strength, power and muscular endurance, while also helping you shed more body fat than you would through training alone.

Clearing The Arteries Of Danger
Despite years of speculation that betaine may be important for muscle, scientists couldn’t figure out exactly how it worked. Recently, multiple clues to this complex puzzle have started to emerge by examining betaine’s most notorious role in the body: as a methyl donor. This process, called methylation, is essential for many functions that keep the body running smoothly. In particular, betaine donates a methyl group to the amino acid homocysteine, converting it to methionine, which effectively reduces blood homocysteine levels.

This seemingly simple step affects multiple parts of the body. For starters, some evidence suggests that elevated homocysteine may increase the formation of clots that damage the inner lining of arteries, thereby promoting the buildup of fatty deposits in blood vessels (atherosclerosis—hardening of the arteries). Therefore, high levels of homocysteine in the blood are not only a known marker of inflammation, but also related to an increased risk of coronary heart disease, stroke and peripheral vascular disease (fatty deposits in peripheral arteries).

Keep in mind that arteries are throughout the body, and therefore clogging doesn’t happen in isolation; what hurts the heart hurts every other part. And though scientists haven’t determined if homocysteine itself is harmful or if it’s just an indicator of increased risk for heart disease, many different health agencies recommend reducing homocysteine levels.

Betaine’s ability to decrease homocysteine results in two beneficial side effects that impact muscle.

• First, decreasing excess homocysteine is beneficial since this amino acid directly impairs insulin signaling, which affects muscle protein synthesis—the processes that underlie increases in strength and muscle size over time.

• Secondly, this process results in the production of methionine, a compound that increases muscle protein synthesis.

Decreasing homocysteine may therefore help your heart, arteries and muscle.

Jacking Up Growth Hormone, Reducing Cortisol
As the story on betaine unfolds, a 2013 study provided more direct evidence indicating that betaine does indeed affect the underlying physiological mechanisms that impact muscle and body composition. In this particular experiment, researchers gave weight-trained men 1.25 g of betaine or a placebo twice per day for two weeks, and put them through a battery of resistance-training tests at the beginning and end of the two-week trial. In addition, they also examined how betaine and the placebo affected anabolic hormones and muscle-signaling proteins.

Although the placebo didn’t alter any of these measures, betaine supplementation resulted in an average 10% increase in growth hormone, a significant increase in insulin-like growth factor-1 (which plays a major role in the regulation of muscle growth), and a significant decrease in the stress hormone cortisol after the resistance-training session at the end of the two-week period.

Despite evidence that betaine affects the processes underlying muscle growth, study results have been mixed, with some studies finding increases in muscular force and power, and others finding no changes, or changes in some muscle groups but not others. Despite these differences, more recent well-designed studies show that betaine can improve measures of strength, power and even body fat.

Testing Betaine On Real Athletes
Here’s a roundup of studies that should interest those who train intensely on a regular basis.

• Increase in upper-body power. In a randomized, double-blind, crossover study, 12 men with resistance-training experience (a minimum of three months) completed two 14-day experimental trials where they took either 1.25 g of betaine or a placebo twice a day. At the beginning and end of the study, they performed a high-intensity strength-and-power challenge, which included bench-press, squat and jump tests. Betaine supplementation led to increases in power and force in selected performance measures, particularly in the smaller, upper-body muscle groups, while there were no significant changes resulting from the placebo.

• Increase in muscular endurance. In another double-blind, crossover study, resistance-trained young men (who worked out three to five days a week on free weights and machines) were given 2.5 g of betaine or a placebo for 14 days. At the end of the study, betaine supplementation resulted in a 6.5% increase in reps and total volume load on the bench press, signifying an increase in muscular endurance. Like the previous study, taking the placebo resulted in no changes.

• Increase in muscle mass and arm size. A 2013 study followed 23 young men, ages 18–35, who worked out regularly over the course of a six-week periodized weight-training program consisting of three two-week microcycles. One group was given 1.25 g of betaine twice a day, for a total of 2.5 g daily, while the other was given a placebo. The men taking betaine increased muscle mass and arm size (by almost 5 cm!) and decreased body fat by about 18%, whereas the placebo group saw no changes in muscle mass or body fat.

What makes these results even more impressive is the fact that these men weren’t novice weightlifters, but instead had an average of 4.8 years of weightlifting experience behind them, yet they saw significant changes in just six weeks. Additionally, this study provides evidence of the synergistic effect of betaine with a well-designed resistance-training program. If you want results, you can’t just supplement; training is the most important factor. However, you may get better results by supplementing with betaine.

Where To Find Betaine
There are three main ways you can ramp up your betaine levels.

• Whole foods. Betaine is found in wheat bran and germ, spinach, beets, pretzels, shrimp and wheat bread. Although there is no data on the average amount of betaine consumed from diet, researchers estimate intake levels ranging from 0.5–2 g per day, with many people falling toward the lower end of this range.

• Choline. In addition to consuming betaine directly, the human body can make it in the liver and kidneys from the essential nutrient choline. Like betaine, choline is a jack-of-many-trades, assisting with metabolism and reducing homocysteine. Choline is found in several foods, including egg yolks, turkey meat, beef, pork and whey.

• Dietary supplements. Supplementation with betaine anhydrous leads to rapid absorption and distribution in body tissues. And though betaine anhydrous is generally considered safe, and no serious side effects have been reported in any of the studies, betaine hydrochloride (or betaine HCL), which at one point was used in over-the-counter medications to increase stomach acid, may cause heartburn when taken in high doses. Because of this, betaine HCL was yanked from the over-the-counter marketplace because there wasn’t enough evidence to consider it “generally recognized as safe and effective.” Look for other forms like BetaPower or regular betaine anhydrous.

How To Use Betaine
Try taking 1.25 g of betaine twice per day. Because it has a good safety record and there are no major side effects associated with betaine, it’s a supplement worth trying. Many manufacturers have noted this research and added betaine to their workout formulas, so read labels to see if betaine is included.

[audiomaniac]

Compared to 40% more testosterone, the effects the supplementation of 1.25g betaine twice a day had on the IGF (+12.4%), GH (+4%) and cortisol (-4.7%) levels