A study performed on 20 highly trained men who took 72 hours to complete a 120km hike in temperatures of 20-26oC, showed that their magnesium levels took three months to return to pre-exercise levels. This study indicates how strenuous muscular activity depletes magnesium reserves and how difficult it can be to restore them. (Doley E, Burstein R, Wishnitzer R, Lubin F, Chetriet A, Shefi M, Deuster PA. Longitudinal study of magnesium status of Israeli military recruits. Magnes Trace Elem 1991-1992;10:420-426.).

Supplementation with magnesium in athletes has been shown to:
•   Have an oxygen sparing effect
•   Increase the clearance of lactic acid
•   Increase muscle strength and power output
•   Improve performance and prevent muscle spasms and cramping.

(Kappes P, Nowacki P, Golf S, Graef V, Temme H, Katz N. Cardiorespiratory and metabolic performance of competitive female endurance athletes after long term magnesium supplementation in a double blind study. 15th Symposium der Gesseschaft fur Magnesium forschung September 1992)

Magnesium – The Regulator
As an electrolyte, magnesium has been shown to exert a regulatory influence by maintaining appropriate levels of potassium, calcium and sodium in the body.

Low magnesium levels are associated with low blood potassium and calcium and also with increased muscle spasm and cramping.

Potassium and Magnesium – To Eliminate Cramping
Potassium is important in energy production with cellular deficiency of potassium being linked to poor muscle performance and fatigue. This is readily demonstrable with patients taking diuretics which deplete both magnesium and potassium. While the fatigue experienced by these patients is usually accredited only to potassium depletion, it is in fact mostly caused by magnesium deficiency. Supplementation with magnesium not only raises magnesium levels, but also potassium levels, even without potassium supplementation.

The body will naturally lose potassium during times of low magnesium levels as an attempt to offset the spasm-inducing effect of low magnesium levels. The loss of potassium reduces the potential of muscles to spasm when there is low magnesium concentration, and supplementation with potassium alone will then generate cramping.

Athletes who experience regular muscle cramps can benefit from magnesium supplementation. Unfortunately, many electrolyte drinks contain plenty of potassium and very little magnesium, if any.

An electrolyte solution containing high levels of magnesium will replenish tissue levels of both magnesium and potassium and therefore reduce cramping.

Calcium and Magnesium – Best results
Calcium release in muscle cells triggers their contraction, so it is vital for healthy muscle function. Excessive calcium accumulation in muscle cells predisposes them to muscle cramps. Magnesium is known as a natural calcium channel blocker. This means that magnesium is able to inhibit the flow of calcium into cells. When magnesium levels are low, muscle cells are more likely to go into spasm because of calcium accumulation. Like potassium, calcium appears to be regulated by magnesium.

Magnesium - How much is enough?
Dietary surveys indicate that the majority of people are not ingesting the required daily amount (RDA) of magnesium. While the typical Australian diet produces 1/2 to 2/3 of the RDA (320 mg) of magnesium, it actually raises magnesium requirements to 500-800 mg due to its high content of magnesium-depleting factors. (Webb WL, Gehi M. Electrolyet and fluid imbalance: neuropsychiatric manifestations. Psychosomantics 1981;22:1991-1203)

Both alcohol and caffeine may cause an increase in magnesium excretion, and high levels of fat have been shown to interfere with magnesium absorption. Increased phosphorous intake (e.g. the phosphoric acid in cola drinks) can
cause an increased need for magnesium, as does a high sugar, salt, protein and fibre intake.

The (magnesium amino acid chelate) magnesium diglycinate used in Endura™ is generally considered to be one of the most advanced sources of oral magnesium available. Most common types of oral magnesium supplementation are in an ionically bonded salt form. This has meant that when the magnesium is released into the body’s system, the magnesium ions have tended to cause gastric discomfort.

Meta Mag™ the patented form of magnesium amino acid chelate used in Endura™ is absorbed directly into the cells much like an amino acid. Other forms of magnesium may cause gastrointestinal upset. The patented form of magnesium in Endura - Meta Mag™ is easily absorbed and reduces the chance of gastrointestinal upset.