1) What is Betaine?
Betaine (otherwise known as trimethylglycine) is a popular pre-workout ingredient for its potential roles in enhancing physical performance and improving body composition.
Betaine is naturally found in the diet in foods such as beets, wheat bran, spinach, & shrimp, but most people tend to intake small amounts from the diet. It can also be derived from the breakdown of the water-soluble vitamin choline in the liver and kidneys.
Betaine’s primary physiological roles is to serve as an osmolyte and methyl donor. As an osmolyte, betaine can help maintain fluid balance and protecting cells against dehydration. These actions may exert benefits on performance and muscle growth by aiding cellular hydration during exercise and promoting muscle protein synthesis during recovery. As a methyl donor for the transmethylation of homocysteine to methionine in the liver and kidneys, betaine may support the synthesis of creatine along with muscle protein synthesis.
Research involving betaine supplementation has grown over the past several years. Despite some mixed findings, evidence suggests that betaine may enhance body composition and increase markers of muscle strength and power.
QUICK SUMMARY: Betaine serves serve as an osmolyte and methyl donor which could aid in cellular hydration, promote muscle protein synthesis, and support the synthesis of creatine. Betaine supplementation has shown promise for improving body composition and enhancing muscle strength and power.
2) Evidence for effectiveness
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3) Pre-workout benefits of betaine
Following several reports that betaine supplementation improved muscle mass and body composition in animal models such as pigs and chickens, sports nutrition researchers started investigating its muscle building and performance-enhancing effects in humans. In animal models, betaine has shown to improve lipolysis and beta-oxidation, along with inhibiting mechanism of fatty acid and triglyceride synthesis. In other words, based on research in animals, betaine has the potential to promote fat burning and prevent fat gain by influencing various aspects of the way fat is metabolized. Betaine supplementation can also elevate intramuscular concentrations of carnitine, a compound that facilitates the movement of fatty acids into the mitochondria for use as fuel.
Aside from improving body composition, there are also mechanisms by which betaine may boost muscle strength and power performance. First, betaine may increase muscle creatine production. Enhancing creatine stores is well-documented to improve the rate of ATP regeneration, enhance high-intensity exercise capacity, and delay fatigue during repeated bouts of high-intensity effort such as sprints and weightlifting. Via its role as a methyl donor, betaine can add a methyl group to guanidinoacetate to synthesize creatine. Some of betaine’s ergogenic properties may simply be explained by its ability to increase endogenous creatine production. Next, one study found that betaine supplementation elevated blood nitric oxide levels and improved vascular function. Improved nitric oxide bioavailability can induce many favorable physiological effects to enhance exercise performance, including improved blood flow. Better blood flow can improve delivery of blood, oxygen, and nutrients to the working muscles and aid in the removal of metabolic byproducts that we want eliminated from the muscle. Lastly, betaine’s role as an osmolyte may counteract the osmotic stress of exercise by aiding fluid balance in muscle fibers – improving “the pump” and muscle-building properties. Over time, elevations in muscle protein synthesis and muscle gain would increase force output and power.
Betaine supplementation has the potential to support fat burning, increase endogenous creatine production, improve blood flow, and increase muscle-building capacity, thereby improving body composition, strength, and power.
4) The latest science
Despite the favorable evidence in animals and promising mechanistic rationale, the human research investigating the effects of betaine supplementation is quite limited and unfortunately rather inconclusive. First, let’s delve into the performance research. Studies providing short-term betaine supplementation (7-15 days) have reported improvements in variables such as muscle endurance during resistance exercise, vertical jumping power, cycling sprint power, and training volume load, while others failed to show any improvements on strength and power performance and force output. While these initial findings were not remarkably overwhelming, it is important to note that these studies were short in duration. Based on betaine’s possible mechanisms of action, strength and power enhancement would likely be more prominent over time as a result of improved training quality and volume load. A recent review on the topic highlighted a lack of evidence for a clear ergogenic effect of betaine on strength and power performance but emphasized that the ergogenic potential of betaine cannot be ignored highlighting the fact that more research is necessary. Only a few studies have investigated the chronic (6-9 weeks) effects of betaine supplementation. Collectively, the studies suggest that betaine may allow for an increased training volume, but this did not translate to better improvements in strength following the program. Similarly, there is not enough evidence to draw definitive conclusions on how effective betaine supplementation is in humans
Now, what about muscle gain and fat loss? Few studies have adequately investigated the effects of betaine on body composition. There have been two reviews of the literature published on the topic. The first review reported that betaine supplementation significantly reduced total body fat mass and body fat percentage, without altering body weight and body mass index. A subsequent review failed to report any benefit of betaine supplementation on body composition. However, both conclusions should be interpreted with caution based the limited amount of evidence, short-term study designs, and the inclusion of non-athletic populations. Only two studies have used an adequate supplementation period (6-9 weeks; 2.5 grams daily) in combination with a resistance training program. Both studies reported significant improvements in body fat percentage and fat mass in the betaine group compared with a placebo group. One reported a reduction in fat mass along with an increase in muscle mass following a 6-week resistance training program in healthy young men. The other reported superior fat loss with betaine supplementation following a 9-week resistance training program in healthy young women. Therefore, the current evidence is limited, but promising.
While betaine is a popular ingredient in pre-workout formulas, further research is warranted to understand how effective it is for improving strength, power, and body composition. However, there have been some promising findings on performance and reductions in fat mass.
5) Other health benefits of betaine
Higher fasting concentrations of homocysteine are associated with some cardiovascular risk factors such as elevated inflammatory markers, triglycerides, and blood glucose concentrations. Betaine serves as a methyl donor for the transmethylation of homocysteine to methionine making it an effective supplement for decreasing plasma homocysteine. This homocysteine-lowering property of betaine has been suggested to lessen the risk of cardiovascular disease. A comprehensive review investigating the influence of betaine supplementation on cardiovascular disease reported that doses greater than 4 grams per day might elicit adverse effects on total and LDL cholesterol; however, supplementation with less than 4 grams per day stimulated the homocysteine-lowering effect without elevating blood lipid concentrations. In summary, supplementation with betaine at a dose lower than 4 grams per day may offer therapeutic effects on cardiovascular risk.
When supplemented at a dose lower than 4 grams per day, betaine reduces homocysteine concentrations offering a cardioprotective effect.
6) What to look for on the label – Recommended dosage
Almost all the studies examining betaine’s efficacy for improving muscle strength, power, and body composition have provided a daily dose of 2.5 grams in the form of betaine anhydrous. Given the mixed findings in the research, it can be inferred that this is at least the minimum effective dose. This is a dose that would be difficult and impractical to attain from diet alone – requiring more than 16 cups of spinach per day. In several studies, the betaine dose was split into 1.25 grams twice per day. However, since betaine is rapidly absorbed with plasma levels peaking after 40 to 60 minutes, consuming 2.5 grams of betaine a part of a pre-workout supplement 40-60 minutes before exercise is a practical, and possibly superior, strategy. Hypothetically, a greater dose may be a more effective performance booster, however this has not yet been tested. Regular usage of betaine would likely exert more favorable effects than a single acute dose. No side effects have been reported in studies using 2.5 grams per day, plus betaine has also shown to be well-tolerated at higher doses. There does not seem to be any eminent risk of ingestion, but more chronic studies are needed to evaluate the effects of long-term usage.
The most researched dose of betaine is 2.5 grams per day, and this is likely the minimum effective dose.
7) Synergistic effect with other pre-workout ingredients?
Given betaine’s potential role in creatine synthesis, one study has evaluated the potential additive effects of creatine and betaine supplementation over a 10-day period. Subjects received either a daily placebo, 2 grams of betaine, 20 grams of creatine, or a combination of 2 grams betaine and 20 grams creatine. While the creatine groups significantly increased muscle creatine concentrations after the 10 days, the betaine group did not show a significant increase in muscle creatine concentrations. Likewise, combining betaine with creatine did not further increase muscle creatine concentrations. Additionally, betaine did not affect strength and power performance. The current evidence in support of betaine’s ability to augment muscle creatine stores is lacking. On another note, while this has not been evaluated, betaine may work well with other nitric oxide boosters such as L-citrulline and nitrates.
The current research suggests that direct supplementation with creatine remains superior for increasing muscle creatine stores, with no added effect from combining betaine.