Betaine is a naturally occurring compound found in various foods, such as beets, spinach, and whole grains. It is classified as an amino acid derivative and plays a role in several biological processes, including the metabolism of homocysteine, an amino acid linked to heart health. In addition to its dietary sources, Betaine is often used as a dietary supplement to support athletic performance and improve muscle endurance. Research suggests that it may enhance physical performance by increasing strength and power output during exercise, making it popular among athletes and fitness enthusiasts.