Magnesium and Sports Performance

Below is the text of a research paper I did for a course in Sports Massage. It explains how magnesium is related to sports performance, and how to raise blood levels of this essential mineral. Hope you enjoy it.

Magnesium, Epsom Salts and Sports Performance;
or, How to become a better athlete just by soaking in the tub

A Paper by Laura A. Sosnowski
Sports Massage class, Fall 2008
Instructor: Stephanie Petersen

Supplementation among athletes at any level has become a booming industry, with most attention and dollars focused on exotic and potentially harmful anabolic steroids. However, perhaps their attention should focus more on the basics of vitamins and minerals, essential elements that are commonly deficient even among apparently well-fed Americans. Specifically, we will examine magnesium deficiency and depletion, and the effects of supplementation on sports performance as well
as overall health.

According to an online reference, the average mixed American diet supplies about 120 mg of
magnesium per 1,000 calories (NationMaster.org, 2003-2005), yet according to revised dietary
guidelines, that intake level can well put most of us into depletion territory.

Magnesium is the eighth most abundant element found within the human body; a 190-lb person possesses approximately 1 oz (23 gr) of magnesium (faqs.org). Yet at least ten percent of us are deficient in magnesium. Most of us do not recognize the signs of magnesium insufficiency until blood levels drop to severe levels; symptoms include personality changes, muscle spasms, tremors, numbness and tingling and in extreme instances, convulsions and delirium (NationMaster.com, 2003-2005).

Magnesium is essential to both bone and muscle health, with the most important muscle in the body,
the heart, especially vulnerable to signs of deficiency.
The body stores about half its magnesium inside the cells of tissues and organs. The other half is
combined with calcium and phosphorus inside bones. A tiny amount—just 1 percent—of the body's
magnesium circulates within the blood at a constant level (Lukaski et al, 2004).

The absorption of orally administered magnesium is unpredictable, but 45 percent is the usual
estimate. Both magnesium hydroxide and magnesium oxide are capable of raising serum magnesium
levels when administered orally (NationMaster.com, 2003-2005).

Research on the effects of supplementation on sports performance or on other performance measures has been frustrating due to inconsistent results; but it is difficult to determine which form of magnesium was used in each study and whether one form is more easily absorbed than another. Different forms of magnesium also vary widely in actual magnesium content. See charts below for details.

Percent Magnesium Content of Oral Supplements
Mg Oxide -- Mg 60 percent
Mg Carbonate -- 45 percent
Mg Hydroxide -- 42 percent
Mg Citrate -- 16 percent
Mg Lactate -- 12 percent
Mg Chloride -- 12 percent
Mg Sulfate -- 10 percent

As you can see, supplements vary widely in levels of actual magnesium content. (Data from National Institutes of Health, Office of Dietary Supplements, 2005.)

What other functions and health conditions are affected by low magnesium levels?

Hypertension – “An observational study with four years of follow-up, found that a lower risk of hypertension was associated with dietary patterns that provided more magnesium, potassium, and dietary fiber... Foods high in magnesium are frequently high in potassium and dietary fiber. This makes it difficult to evaluate the independent effect of magnesium on blood pressure.”

Diabetes – “Magnesium plays an important role in carbohydrate metabolism. It may influence the release and activity of insulin, the hormone that helps control blood glucose (sugar) levels. Low blood levels of magnesium (hypomagnesemia) are frequently seen in individuals with type 2 diabetes. Hypomagnesemia may worsen insulin resistance, a condition that often precedes diabetes, or may be a consequence of insulin resistance.”

Osteoporosis – “Bone health is supported by many factors, most notably calcium and vitamin D.
However, some evidence suggests that magnesium deficiency may be an additional risk factor for
postmenopausal osteoporosis. This may be due to the fact that magnesium deficiency alters calcium
metabolism and the hormones that regulate calcium. Several human studies have suggested that
magnesium supplementation may improve bone mineral density.”

Cardiovascular Disease – “Some observational surveys have associated higher blood levels of
magnesium with lower risk of coronary heart disease. In addition, some dietary surveys have suggested
that a higher magnesium intake may reduce the risk of having a stroke. There is also evidence that low
body stores of magnesium increase the risk of abnormal heart rhythms.” (All four above quotes from
National Institutes of Health page on Magnesium, 2005.)

Mitral Valve Prolapse – “A significant body of evidence [suggests] that magnesium deficiency is at least a symptom of MVP and that many of the symptoms of MVP syndrome are reduced or resolved by magnesium supplementation” (Nelson, 2007).

Some recent sports and exercise studies show that healthy levels of magnesium help human
beings to perform work and exercise with less effort and tire far less quickly. The Henry Lukaski and
Forrest Nielsen studies put a small group of post-menopausal women on a normal but supplemented
diet for 35 days, then on a magnesium depletion diet for 93 days, and then back on a supplemented diet for 49 days. They were put through exercise tests at the end of each dietary phase. The women in a magnesium depleted status required more oxygen to to reach their target heart rate on the exercycle; in other words, their muscles required more oxygen to do the same amount of work (Lukaski, 2002). Related studies show that muscles tire more quickly when in a magnesium-depleted state.

Events that take from one to seven minutes to complete were the most affected. A list of athletic events
in that range include running a mile or the 1500 meters, or swimming several laps of a pool. A 1998
German study tested blood samples of triathletes – athletes who swim 500 meters, bike 20 kilometers,
and run 5 kilometers. Those with magnesium orotate supplementation showed higher blood levels of
oxygen (an increase of 208% compared to an increase of 126% in the controls), while showing better
performance times (Golf et al, 1998).

Modern Americans' levels of dietary magnesium are further impacted negatively by the depletion of magnesium levels in the soil, as a result of intensive agriculture. Rejection of hard water over artificially softened water also leaves us without a common, natural and free source of dissolved magnesium. E.B. Flink, author of "Magnesium Deficiency in Human Subjects: A Personal Historical Perspective," has listed numerous causes of magnesium deficiency. He classifies them into nutritional causes (dietary insufficiency, alcoholism); intestinal causes (diarrhea, malabsorption); excess loss of magnesium through the kidneys (due to disease or the influence of drugs, especially diuretics); endocrine and metabolism causes (hyperthyroidism, pregnancy, excessive lactation, high levels of serum calcium); and genetic and neonatal causes (Myerson, 1989).

Not only is the soil depleted, but our efforts to supplement with calcium has thrown all our
dietary minerals out of balance: “Interestingly, our focus on getting enough calcium is another factor in
decreased magnesium levels. In a delicate dance of balance, calcium depletes magnesium yet calcium
functions best when enough magnesium is present. Studies indicate that taking a calcium supplement
without enough magnesium can increase the shortage of both nutrients. Researchers have found that
many Americans have five times as much calcium as magnesium in their bodies, although the proper
ratio for optimum absorption of both minerals is two to one” (Breyer, 2008).

Liquids with dissolved magnesium may be the most effective way to quickly restore blood levels of this element. An astonishing British study showed that merely taking Epsom salt baths for twelve minutes a day can raise blood levels. And with some evidence that those who drink hard water have the benefit of improved heart health, it is also interesting that Dasani bottled water has some magnesium sulfate added to improve “mouth feel” (NationMaster, 2003-2005).

The above-mentioned British study was conducted by the University of Birmingham with a small group of subjects. Blood levels of magnesium rose by an average of ten parts per million just after one bath, and rose an average of nearly 40 ppm after a week of daily baths. It seems astonishing that a mineral could cross the skin barrier, but I suspect that the sulfur helped to transfer the mineral.

To quote the study:

In other experiments using excised human skin, we found that sulfate does penetrate across the skin barrier. This is quite rapid so probably involves a sulfate transporter protein... To check this, 2
volunteers wore ‘patches’ where solid MgSO4 was applied directly to the skin and sealed with a waterproof plaster. Plasma/urine analysis confirmed that both Mg and sulfate levels had increased so this is potentially a valuable way of ensuring Epsom salts dosage if bathing is not available.
Interestingly, both volunteers, who were > 60 years old, commented without prompting that ‘rheumatic’ pains had disappeared (Waring, 2004).

Using the skin to “inject” magnesium supplements into one's system opens up a whole new range of options. Suggestions listed in one article to combine it with lotion or coconut oil, to sponge bathe in a solution, or to spray it on oneself like a mist, do not seem so far-fetched after all (EnzymeStuff.com, 2002).

One wonders if magnesium depletion is at the root causes of the little understood phenomenon of fibromyalgia, chronic fatigue syndrome, and other modern ills. It is disappointing to note that studies using magnesium to treat CFS have had mixed results (MotherNature.com, 1998-2005).

One can only hope that our craze for calcium will abate, and be replaced with a healthier concern for a natural, organic, and balanced diet, together with the simple self-treatments our grandmothers used.

(A couple other charts were included in the paper, but they do not transfer well to this format. However, please refer to the U.S. Department of Agriculture's Nutrient
Database Web site: http://www.nal.usda.gov/fnic/cgi-bin/nut_search.pl. for a chart of foods rich in magnesium. Also, you may look up the chart of recommended daily allowances for all ages at the Office of Dietary Supplements, National Institutes of Health, 2005.)

SOURCES:
Breyer, Melissa, Amazing Health Benefits of Epsom Salt Baths, Care2 Green Living, April 2008, http://
www.care2.com/greenliving/health-benefits-of-epsom-salt-baths.html .
Epsom Salts, EnzymeStuff.com, 2002 -- updated Aug. 2005,
http://www.enzymestuff.com/epsomsalts.htm .
Golf, S.W., Bender, S., and Gruttner, J. On the significance of magnesium in extreme physical
stress, Institute of Clinical Chemistry and Pathobiochemistry, University Medical School, Justus-
Liebig-University, Giessen, Germany, 1998, abstract at http://cat.inist.fr/?
aModele=afficheN&cpsidt=1638288.
Lack Energy? Maybe It's Your Magnesium Levels, USDA, May 2004, http://www.ars.usda.gov/is/AR/
archive/may04/energy0504.htm . (Reprinted from the May 2004 issue of Agricultural Research
magazine.)
Lukaski, Henry C; Nielsen, Forrest H, Dietary magnesium depletion affects metabolic responses during
submaximal exercise in postmenopausal women, The Journal of Nutrition, May, 2002,
http://findarticles.com/p/articles/mi_7229/is_/ai_n30048561?tag=artBody;col1 (abstract), and as PDF
at http://jn.nutrition.org/cgi/reprint/132/5/930.pdf.
Magnesium, Faqs.org, www.faqs.org/sports-science/Je-Mo/Magnesium.html, undated .
Magnesium, NationMaster.com encyclopedia, 2003-2005, http://www.nationmaster.com/encyclopedia/
Magnesium-sulfate .
Magnesium, MotherNature.com, 1995-2008,
http://www.mothernature.com/Library/Ency/Index.cfm/Id/2879002.
Magnesium, Office of Dietary Supplements, National Institutes of Health, Jan. 2005,
http://ods.od.nih.gov/factsheets/magnesium.asp .
Myerson, Ralph, Magnesium maximizes heart health; magnesium appears to be essential for the
integrity of the heart, Better Nutrition, Dec. 1989,
http://findarticles.com/p/articles/mi_m0860/is_n12_v51/ai_8199735.
Nelson, Terry, The dangers of magnesium deficiency in endurance athletes, Organ Internist, Dec. 2007,
http://findarticles.com/p/articles/mi_m0FDL/is_/ai_n24940334 .
Waring, R.H., Report on Absorption of magnesium sulfate (Epsom salts) across the skin, University of
Birmingham, 2004,
http://www.epsomsaltcouncil.org/articles/Report_on_Absorption_of_magnesium_sulfate.pdf .