Supplement Review: Betaine; A Proven Athletic Performance Enhancer

Betaine is a methyl derivative of glycine that was first isolated from sugar beets. Formerly known as trimethylglycine, it can be found in spinach and some wheat based foods. Interestingly, in the past decade it has become one of the primary supplements used in preworkouts.

Evidence: The performance enhancing effects have been studied with doses ranging from 500 mg - 9000g per day in a variety of animal and human models. The first studies occurred in 1952 in poliomyelitis patients(1). Betaine supplementation showed improvements in strength and endurance in these subjects. Later, in 1999, it was shown to improve lactate metabolism and hydration in horses who were exercised to fatigue (2). This lead more scientists to investigate the potential ergogenic effects of betaine in humans.

Researchers at the University of Connecticut found that men taking 1.25g of betaine 2x per day for two weeks had a 10% increase in GH, a 10% increase in IGF-1, and a 15% decrease in cortisol compared to control. They also found that betaine increased biomarkers for muscle protein synthesis after the workouts. In another study 14 days of betaine supplementation increased reps to fatigue in the bench press when using 50% of 1 rep max.

Another study showed improvements in vertical jump, power output, bench press and force production after 12 days of supplementation (3,4). One group even demonstrated improved repetitions to fatigue in the squat (5). These studies provide evidence that supplementing with betaine can improve performance.

The mechanism of how betaine works is not clear yet. Although some scientists suggest that it may enhance creatine synthesis. Others, suggest that the osymolytic effects may play a role. Betaine causes the muscle cell to be optimally hydrated and therefore it can enhance glycolytic flux during high volume training periods. In addition, multiple studies report (6) that betaine can reduce perception of fatigue during exercise. This translates to improved motivation, which can help push through the end of a workout. There is also evidence to show that it helps post workout recovery.

Side Effects: There are over a dozen studies where betaine has been given orally to humans, yet no study has reported any severe negative side-effects. However, it can cause nausea, upset stomach, or diarrhea in some people.

Bottom Line: Betaine has been proven to enhance performance the most in exercise that creates a lot of metabolic stress, much like most bodybuilding programs with high volume and short rest periods. Several studies show evidence that 2.5g/day of betaine supplementation can improve strength training performance or power based exercise.

1. Borsook ME, Billig HK, Golseth JG (1952) Betaine and glycocyamine in the treatment of disability resulting from acute anterior poliomyelitis. Ann West Med Surg 6:423–427

2. Warren LK, Lawrence LM, Thompson KN (1999) The influence of betaine on untrained and trained horses exercising to fatigue. J Anim Sci 77:677–684

3. Lee, E. C., et al. Ergogenic effects of betaine supplementation on strength and power performance. J Int Soc Sports Nutr 7:27, 2010.

4. Craig, S. A. Betaine in human nutrition. Am J Clin Nutr 80: 539–549, 2004.

5. Hoffman, J. R., et al. Effect of betaine supplementation on power performance and fatigue. J Int Soc Sports Nutr 6:7, 2009.

6. Armstrong LE, Casa DJ, Roti MW, Lee EC, Craig SA, Sutherland JW, Faila KA, Maresh CM. Influence of betaine consumption on strenuous running and sprinting in a hot environment. JSCR 2008.May;22(3):851-60.