As an essential mineral, magnesium is the fourth most abundant element (behind sodium, potassium, and calcium) found in the body, with a total of 50%-60% being stored in the skeletal system and the remainder being stored in muscles and soft tissues. Magnesium can be found naturally in such dietary sources as pumpkin seeds, nuts, whole grains, and legumes. The current RDA is 400-420 mg for adult males and 310-320 mg for adult females. It is thought that athletes may require additional magnesium above the current RDA to accommodate the increased metabolic demands of exercise and offset losses from sweating.
Magnesium plays an instrumental role in maintaining both structural (bone) and biochemical (muscle contraction, nerve transmission, enzyme production) homeostasis in the human body. Magnesium is responsible for 80% of all enzymatic reactions in the body; it regulates virtually every activity, making attainment and maintenance of magnesium balance crucial to an athlete’s overall health. Of particular importance from a performance standpoint is the fact that magnesium is required for both aerobic and anaerobic energy production. Magnesium is also involved in reactions necessary for electrolyte balance. Because prolonged exercise increases magnesium loss via sweat, it is thought that supplementation during exercise, generally in the form of a sport drink or electrolyte capsules, is important for protection against muscle weakness and cramping. Athletes, particularly those with poor dietary intake of magnesium, may benefit from enhanced metabolic efficiency during exercise, helping to improve strength, power, and endurance performance.Magnesium also aids bone health by protecting against bone loss and consequent risk of fracture.
A small, well-designed study of women found a month-long period of magnesium restriction (112 mg/day or 36% of the RDA), an intake not uncommon among athletes eating primarily refined, processed foods, to significantly increase the peak oxygen uptake, total and cumulative net oxygen usage, and heart rate for a given training workload in comparison to a period when sufficient magnesium (based on the RDA) was provided through whole foods and supplementation. Furthermore, as the level of magnesium deficiency intensified, so did the metabolic cost of exercise, an established detriment to performance.
Are You at Risk for Magnesium Deficiency?
- I am following a high-protein diet (excessive intake increases urinary loss of magnesium).
- I eat primarily packaged foods and fast food (processed foods are generally lacking in magnesium).
- The fat content in my diet is greater than 30% of my daily calorie intake (high-fat diets reduce absorption of magnesium).
- I drink a lot of carbonated beverages such as soda (phosphoric acid in carbonated drinks prevents absorption of magnesium within the GI tract).
- I’m a heavy sweater and train 3+ hours daily (sweat losses may be great enough to warrant increased intake).
- I regularly consume alcoholic beverages (increases excretion of magnesium).
- I’m taking medication (some antibiotics, diuretics, birth control pills, and steroids can increase excretion of magnesium).
Magnesium is generally bound with salts such as gluconate, citrate, and aspartate for supplement use and is available in tablet, capsule, powder, and liquid form. Magnesium is also commonly added as an electrolyte to sport drinks and products. As a daily supplement, typical doses range from 100 to 350 mg. Magnesium is best taken with food to minimize adverse side effects. To offset sweat losses, athletes training or racing longer than 3 hours should replace 20-30 mg of magnesium per 8-12 oz (.24-.35 L) of fluid ingested.
UPPERCLIMB SOAR and ASCEND have natural sources of Magnesium.
The most common side effect associated with magnesium supplementation, generally at single doses of greater than 350 mg (the current upper tolerable limit for supplement use in adults and adolescents) is diarrhea. Abdominal pain and nausea have also been reported at high doses.