Magnesium helps convert food into energy, and since our bodies use magnesium during exercise, a supplement can help to support endurance. When magnesium is at a low level in our system, lactic acid builds up. You know that post-workout pain? Most likely, that's due the effects of a lactic acid buildup. Magnesium to the rescue, as it works to mitigate pain and cramping by lowering lactic acid levels and restoring the body's pH. Magnesium Citrate by The Vitamin Shoppe brand offers 200 mg of magnesium prepared with citrate, a form that's highly usable by the body.Benefits: 50% Daily Value (DV) of Magnesium; 200 mg Promotes energy production May help muscles relax Gluten-free Dairy-free Soy-free Nut-free