Do Magnesium Supplements Prevent Cramping?

Anyone who has suffered from a muscle cramp during or after exercise understands that it’s definitely something worth trying to avoid. For those who have been lucky enough to evade them, a muscle cramp is a sudden, involuntary, painful contraction of a muscle. These symptoms generally ease off within seconds to minutes, but are often accompanied by a palpable knotting of the muscle. While magnesium does play many important roles in the body, unfortunately the prevention/reduction of exercise-induced muscle cramps is not one of these. It is easy to be confused considering the heavy marketing for magnesium supplements and the prevention of cramps, but to date the scientific research suggests that there is no strong link between exercise-induced muscle cramps and magnesium supplementation.

While oral magnesium does not appear to have any beneficial effects in athletes with adequate magnesium, supplementation may improve performance in individuals with a diagnosed deficiency. Those undertaking a high volume chronic training load (e.g. long distance runners) or those with a restricted energy intake may be at risk of magnesium deficiency, although this is not common and you should always get this checked out with your GP before supplementation. It is worthwhile noting that the intestinal absorption of magnesium varies depending on how much magnesium the body needs. If there is too much magnesium, the body will only absorb as much as it needs. So how much do I need? I hear you ask. The recommendations suggest that adults consume a range between 350 and 400 mg/day as the upper limit. Most individuals who are eating a healthy well balanced diet will be acquiring the required amount of magnesium through wholefoods. Good food sources of magnesium include vegetables, legumes, fish, nuts and whole grains. For example, 30g of brazil nuts provides about 100mg, and ½ cup cooked quinoa provides about 50mg of magnesium.