Magnesium is the mineral that tells your muscles when to let go. 🔬 Every time a nerve fires or a muscle contracts, electrolytes cross your cell membranes, and magnesium helps regulate it. It pairs with calcium to run the show: calcium starts a contraction, magnesium helps the muscle relax afterward. Your heart runs on the same balance. Magnesium keeps its electrical signals steady and helps blood vessels relax and widen when needed. Contraction gets the credit, but relaxation is just as vital.