Mag Cal Formula 2 supports muscle and bone health using a combination of magnesium, calcium and vitamin D. Each of these active ingredients plays an important role in maintaining optimal muscle function and bone mineral density. Magnesium is a cofactor for the enzyme creatine kinase, which generates ATP from phosphocreatine stored in muscle tissues during intense exercise (known as alactic anaerobic metabolism.) In a double-blind, placebo controlled clinical study conducted on 25 healthy male volleyball players with normal magnesium levels, supplementation with 350 mg of magnesium oxide for 4 weeks supported muscle function associated with intense exercise, by improving alactic anaerobic metabolism. Following supplementation, lactate production during peak exercise was significantly reduced in the magnesium group in comparison with baseline measurements.