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Everything You Wanted to Know About Magnesium and Endurance

magnesium benefits for exercise

Week three of #30SaltyDays kicks off today, and we’re tackling one of the more obscure electrolytes: magnesium. If you’ve dealt with cramping, fatigue or headaches, you may be battling with a magnesium deficiency. As you’ll see, such deficiencies have been linked with hampered exercise performance, which is bad news for any runner or endurance athlete!

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This post is part of our #30SaltyDays summer campaign, in which we hope to educate YOU about the benefits and science behind electrolytes. Follow the campaign with the hashtag #30SaltyDays on Facebook, Twitter, Instagram and the SaltStick blog. We’re offering our brand new product, SaltStick FASTCHEWS, as a GIVEAWAY for participants. More information here: http://bit.ly/1Rz0avu

Read on below for information about:

  1. How your body uses magnesium to regulate produce energy, cool off, and other important processes.
  2. Why endurance athletes should care about magnesium, especially when it comes to exercise performance.
  3. How to identify and manage a magnesium deficiency
  4. How YOU can incorporate this knowledge into your daily nutrition.

How does the body use magnesium?

Overall, magnesium is a bit of a wonder-mineral. It’s required for more than 300 different biological processes, and we’ve listed the major processes below. Unfortunately, despite magnesium’s importance in everything from regulating blood pressure to bone health, more than 57 percent of U.S. adults do not consume adequate amounts, according to the USDA. If you’re not meeting your daily needs (which are higher for athletes than sedentary adults), then you’re hampering your body’s ability to perform the following processes:

Energy production: Magnesium is crucial for the production of ATP, which is how your body “packages” energy. The body breaks down glucose from the bloodstream into ATP molecules, and these molecules are used to fuel cell functions that contribute to muscle contraction and metabolism. A magnesium deficiency can often result in lethargy, which is the result of a hampered energy-production process. A 2003 study found that magnesium supplementation resulted in increased exercise stamina, relative to a placebo. Same goes for a later 2006 study, which found magnesium supplementation helped decrease the fatigue-inducing effects of lactate buildup.

Sweat: Though not in great amounts — unlike sodium and potassium — trace amounts of magnesium are lost through sweat, and they will need to be replaced. Luckily, each SaltStick Capsule contains magnesium in an amount proportional to the other electrolytes in sweat.

Muscle contraction: Mustard is currently a popular method used to prevent cramping in tennis players, and some researchers believe this is due to mustard’s high magnesium content. There’s no consensus or definitive study; however, many tennis player swear by its effects. Additionally, some endurance athletes report that magnesium supplementation has helped reduced chronic muscular tension.

Bone formation: Although calcium is a little more famous for building strong bones, magnesium is no less important. The body uses these two minerals together for bone health, and several studies of rats have found that magnesium deficiencies are linked to higher-than-normal risk for osteoporosis (Journal of the American College of Nutrition, 2009; Osteoporosis International, 2006).

Antioxidant: A growing body of evidence suggests that magnesium also acts as an antioxidant, protecting the body against free-radical damage. This is especially important to athletes, because free radicals can disrupt the body’s ability to recover, causing inflammation and reduced performance. A 2003 study of diabetic rats found that magnesium supplementation reduced oxidative damage caused by artificially-induced diabetes. A later 2007 scientific review argued that magnesium deficiency “induces a systemic stress response,” and “contributes to an exaggerated response to immune stress and oxidative stress.” The review also argued that inflammation caused by magnesium deficiencies contributed to risk for metabolic syndrome.

Should endurance athletes care about magnesium?

“Magnesium supplementation or increased dietary intake of magnesium will have beneficial effects on exercise performance in magnesium-deficient individuals,” concludes a 2006 scientific review. Additionally, magnesium deficiencies have been shown to harm athletic performance, due to impaired carbohydrate metabolism and increased oxidative stress.

A 2002 study of 10 women found markers of physical fitness (reduced oxygen uptake and heart rate at certain intensities) fell in direct proportion to levels of magnesium deficiencies. The study took place over three months, during which women were given the recommended daily amount (RDA) of magnesium for the first month, reduced levels of magnesium for the second month, and RDA levels for the third month. At the end of each month, oxygen uptake levels and heart rate were measured while the women exercised by cycling indoors. Oxygen intake and heart rate levels were significantly higher during the second month, but resumed to normal after the third month, thus indicating adequate magnesium levels are necessary for maximum exercise performance.

Notably, researchers have concluded that while magnesium deficiencies harm athletic performance, the benefits of magnesium supplementation stop once RDA levels are achieved. Consuming additional magnesium has not been shown to improve performance. Still, it is very important for athletes to be aware of magnesium levels, as strenuous exercise is associated with increased needs for magnesium, due to mineral loss through sweat and urination. This is especially cause for concern given that more than 60 percent of men and women consume less than the RDA for sedentary people.

In conclusion, the answer is obvious: Yes, magnesium is crucial for endurance success.

Magnesium deficiency symptoms:

Because magnesium is essential for more than 300 different bodily functions, a deficiency can manifest itself in just as many ways. As Triathlete Magazine correctly points out: “Athletes in particular might find it easy to explain away fatigue or muscle cramps, lowered immunity, and even altered heart rates, and indeed these symptoms are common and multi-faceted in cause. However, a simple magnesium deficiency could also be the underlying factor.”

The biggest symptoms include chronic fatigue and muscle cramps, but these are not exclusively caused by a magnesium deficiency. Nor are other common symptoms, such as migraines, anemia, depression, irregular heart rates, or insulin resistance. How, then, would one know if a magnesium deficiency is the cause?

We suggest checking your diet. The body does not produce magnesium, and the mineral must be absorbed from food or supplements. The following dietary traits could indicate you aren’t meeting your magnesium needs:

  • High levels of alcohol consumption
  • Low levels of dark leafy greens, legumes, nuts, seeds and whole grains (all excellent sources of magnesium)
  • A calorie-restricted diet (in effort to lose or control weight) of less than 1,800 calories per day
  • High levels of sugars or sugary drinks

How should endurance athletes incorporate magnesium into their daily diets?

Race nutrition: How SaltStick can help: Like all nutrients needed by the body, an athlete’s ideal magnesium levels can only be determined in relation to every other mineral in the body, particularly calcium. (We cover this concept more extensively in this blog post about ratio-based nutrition.) When it comes to electrolytes lost through sweat, sodium, potassium, calcium and magnesium are lost in a 220-63-16-8 ratio for the average athlete. To ensure the full spectrum of electrolytes is replaced, a SaltStick Capsule conveniently provides the same ratio, and in a form and quantity the body can absorb. While the exact ratio also varies from person-to-person, supplying your body with building blocks in about the right amount is key. For the athlete interested in how SaltStick Caps can help maintain electrolyte levels during training, we provide a complete suggested usage guide here: Training with SaltStick Capsules.

Outside of training and racing, magnesium can be obtained naturally. Athletes can meet their daily magnesium needs by including foods rich in magnesium content. These include:

  • Pumpkin seeds (532 mg per serving)
  • Almonds (300 mg per serving)
  • Sesame seeds (200 mg per serving)
  • Walnuts (158 mg per serving)
  • Whole grain bread (85 mg per serving)
  • Spinach (80 mg per serving)
  • Broccoli (30 mg per serving)

Other great options include Brazil nuts, bananas, peanuts and other legumes. If you’re an endurance athlete in the midst of heavy training, you’re likely consuming far more than 1,800 calories per day. As long as you include mid-sized portions of the foods listed above, you’re likely meeting your magnesium needs. For inspiration, check out our recent post about how to include five magnesium-filled foods into your diet. Later this week, we’ll share some delicious recipes to help you get optimal amounts of magnesium!