In addition to improving physical performance in a wide range of people and sports, research has shown that red light therapy can also improve muscle growth. Red light therapy popular in professional sports as well as training and fitness, as red light therapy has been repeatedly shown to improve physical function, enhance muscle mass and speed recovery. This is because our bodies rely on light as an energy source to help our glands regulate adrenaline, testosterone, metabolism and many other functions, and red light therapy has been shown to increase testosterone production, which in turn can improve overall energy levels and even improve peak muscle performance.