What is betaine?
Betaine is the more commonly used name for Trimethylglycine or TMG. TMG is a derivative of the non-essential amino acid glycine. TMG is most commonly found in our diet in beetroots, whole grains, spinach and shellfish.
Why is it important?
One of Betaines primary functions in the body is to aid in fluid balance and actually act like a salt, increasing the water retention of cells. This helps to preserve hydration at the cellular level, which is key for supporting respiration.
Another important function of TMG is that it also plays a role creatine synthesis. In endurance exercise most of the energy we need is produced via our aerobic energy system, but for high intensity bursts or resistance activity lasting less than 30 seconds, the creatine phosphate pathway is more heavily relied upon. This requires the very fast re-synthesis of creatine phosphate and TMG acts as a methyl group donor to support this process.
The benefits for strength exercise could also benefit any athlete looking to improve their body composition. In a study by Lee et al (2010) weight-trained males follow a periodised weight-training program for six weeks. One group supplemented with 1.25 grams of betaine twice per day, and the other group supplemented with a placebo twice per day. Versus the placebo group subjects supplementing with betaine increased muscle mass by 4 pounds and arm size by 10 percent, while they decreased body fat by 7 percent.
Sprint cycling performance has also shown to benefit from betaine supplementation. Pryor et al (2012) investigated betaine supplementation on repeated bout sprint cycling performance and versus the placebo group found supplemented athletes to demonstrate an increased average peak power, increased maximum peak power, increased average mean power, and increased maximum mean power.
Lee E.C., et al. (2010) Ergogenic effects of betaine supplementation on strength and power performance. Journal of the International Society of Sports Nutrition. 19; pp.7-27.
Pryor, J. L., et al. (2012) Effect of betaine supplementation on cycling sprint performance. Journal of the International Society of Sports Nutrition3;9(1): 12