Magnesium deficiencies are more common than we might think, resulting in joint pain, difficulty sleeping, and muscle spasms, which can impact your training and sports performance. About 50% of magnesium is found in your bone and 50% is found in your body’s tissue cells and organs, while less than 1% is in your blood. Therefore, a magnesium deficiency can exacerbate or magnify conditions such as asthma, anxiety, osteoporosis, irregular heartbeat, and high blood pressure.
Role of Magnesium
Magnesium is used by every cell in the body, playing a role in over 300 enzyme reactions in the body each day. It helps to maintain normal nerve and muscle function, heart rhythm, blood pressure, immune system, bone health, blood sugars, and promotes calcium absorption.
Magnesium also helps with electrolyte balance and regulating the amount of calcium in our bodies, which is important for optimal bone and heart health. Athletes are at an increased risk of having a magnesium deficiency since it’s excreted in sweat and urine. During intense training, magnesium is transported from the blood plasma into the red blood cells as activity increases; therefore, athletes’ basic needs are greater than a less active individual. Lifestyle habits that also deplete magnesium, include drinking alcohol, carbonated beverages and caffeine.
Magnesium Testing and Recommendations
The primary focus should be to include more magnesium in your diet,
found in foods such as nuts, seeds, beans, lentils, whole grains like quinoa and brown rice, most fruit, dark chocolate, dark leafy greens, and molasses. However, for some, it can be difficult to get enough magnesium through food to meet the needs of high training demands.
The Recommended Daily Allowance (RDA) for magnesium for men is 400-20 milligrams (mg) per day and 310-320 mg per day for women. It’s been found that approximately 60% of American adults don’t get enough magnesium in their diet increasing risks of chronic inflammation contributing to high blood pressure, diabetes, cancer and heart disease.
Testing for a magnesium deficiency via a blood test is the least sensitive marker of magnesium status since there is a lag time between blood (serum) changes in magnesium and deficiency. The best marker is a magnesium loading test, but this is not a practical test and can be expensive. Therefore, getting an ionized magnesium or a RBC magnesium test are the next best options to evaluate magnesium status.
Magnesium plays a significant role in an athletes bone health and energy, but does it also improve performance? Studies have not confirmed that magnesium is an ergogenic aid and most studies have been performed in younger athletes, not in the master athlete population. Regardless of whether it can actually make you perform better on race day, if you find your diet is deficient, supplementation may be helpful.
Magnesium glycinate or magnesium bisglycinate is usually what I recommend to athletes. This can be taken orally and is known as a chelated amino acid supplement. This form of magnesium binds to an amino acid and therefore relies on a protein pathway for availability and absorption. Magnesium glycinate is readily available on the market and well tolerated by most individuals. It tends to be a little more expensive because its availability in the body is higher than other forms of magnesium supplementation. Magnesium bisglycinate, is said to be the only form of magnesium able to cross the blood-brain barrier. It is especially useful for athletes who deal with anxiety, headaches, and mood-related or sleep disorders as well.
Magnesium citrate is another suggested supplement, but it works as a laxative, meaning it pulls water into your intestines while relaxing your bowels, possibly causing GI issues. It’s best to avoid magnesium oxide as it has the lowest rate of bioavailability. That means that your body is not able to use much of this form. Be careful as most over-the-counter supplements contain some form of magnesium oxide.
Since magnesium can have a relaxation effect for many individuals, I would suggest taking an entire 200-mg dose 30-60 min before bed. The signs of magnesium deficiency are extremely common, so ideally would be to start with adding more magnesium-rich foods into your diet daily. If you struggle to get the RDA, then consider a supplement as recommended by your physician or sports dietitian. When choosing a supplement that is 3rd party certified by USP or NSF sport.