Final answer:
DHEA is claimed to increase muscle mass and strength because it is a precursor to testosterone, which stimulates muscle formation and leads to increased muscle mass.
Step-by-step explanation:
DHEA is claimed to increase muscle mass and strength because it is a precursor to testosterone, the male sex hormone that stimulates muscle formation and leads to increased muscle mass. Testosterone plays a role in increasing muscle mass and decreasing body fat. Therefore, by providing the body with a precursor to testosterone, DHEA can potentially enhance muscle growth and strength.