Disclosed is a use of a composition comprising a ferrous amino acid chelate for manufacture of a medicine for reducing lactic acid. The medicine comprises a therapeutically effective amount of a ferrous amino acid chelate-containing composition and a pharmaceutically acceptable carrier thereof. The ferrous amino acid chelate-containing composition can effectively reduce the accumulation of lactic acid in cancer cells, reduce the uptake amount of glucose, increase the motility, increase the lactate dehydrogenase, and effectively prevent and treat the related symptoms caused by exercise fatigue.
