Magnesium for Runners

We know sodium for runners is important, but magnesium is another important mineral. This post will break down everything you need to know about magnesium for runners. 

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Disclaimer – This post is for informational purposes only and is not for diagnosing or treatment. See your medical provider or Registered Dietitian for individual recommendations.

Magnesium tends to get little spotlight, compared to sodium and potassium, but it is very important from a functional standpoint, especially for runners and athletes!

Many micronutrients, like magnesium and Vitamin C, play important roles in optimal muscle function and recovery.

What is Magnesium?

Magnesium is the fourth most abundant mineral in the body. It is found in many foods and is a cofactor in over 300 chemical reactions in the body.

In other words, magnesium is very important to the optimal functioning of your body.

Therefore, magnesium for runners is important for optimal performance and ensuring all systems are working properly. Getting enough magnesium will affect performance.

Some of these performance systems include:

  • protein synthesis (important for muscle and power, and recovery)
  • muscle and nerve function
  • vasomotor tone
  • immune system
  • bone integrity
  • promotes calcium absorption, which can promote vitamin D absorption
  • blood glucose control (stable blood glucose is important for avoiding hitting the wall in a marathon)
  • energy production (ATP to fuel your activity
  • transporting calcium and potassium ions across cell membranes to help with nerve impulse conduction and muscle contraction

Forms of Magnesium

There are a few different forms of magnesium that may apply for different conditions. For simplicity purposes, the following are some you may see in stores or when shopping for magnesium running supplements online.

Magnesium citrate – Magnesium citrate is one of the more common magnesium forms and is easily found. It may be among the most bioavailable form as well.

However, it can also be used for constipation so runners should be aware of possible side effects as a laxative, which wouldn’t help with replenishing electrolytes. It may also have a calming effect on the body, so may be good to take before bed.

Magnesium glycinate – This form of magnesium is combined with glycine, an amino acid. It is easily absorbed and is calming to the body.

This form is typically used for treating sleep disturbances, depression, insomnia and anxiety.

Magnesium oxide – Like magnesium citrate, magnesium oxide is often used for constipation or even heartburn.

This is commonly sold in powder or capsule form, and isn’t great for treating magnesium deficiencies, since it is poorly absorbed. Runners should not use this form when supplementing.

Magnesium chloride – Magnesium chloride is formed from a magnesium salt that include chlorine, and is very well absorbed in your digestive tract.

It is commonly used to treat low magnesium levels and GI complaints, like constipation and heartburn. Some runners may even apply it topically to relieve muscle soreness, but it won’t increase magnesium levels that way.

scoop of supplement powder

How Do We Get Magnesium?

We can get magnesium through food sources or through supplements.

Magnesium is in many foods and is widely dispersed, though magnesium supplements for runners may work best for some people based on access to food, dietary preferences, allergies or budget.

Magnesium is also available through Epsom salt baths.

You may be taking in magnesium through leafy greens, nuts and seeds, legumes, whole grains, peanut butter and more. Plus, magnesium is generally added to breakfast cereals and other fortified foods.

An interesting thing to note is that only about 30-40% of the dietary magnesium we consume is actually absorbed by the body.

This is why it’s important to include healthy athlete snacks that are magnesium rich.

Also, check out some of these ideas for lunches for runners.

Most of the magnesium in our body (50-60%) is present in the bones.

Food Sources of Magnesium

You can and should include many food sources of magnesium into your diet, especially when your nutrient needs are higher, during half and full marathon training. 

Some of these foods also offer iron, as iron for runners is very important as well.  

  • pumpkin seeds, roasted, 1 ounce  – 157 mg
  • chia seeds, 1 ounce  – 111 mg (chia seeds pack such a punch, see more about chia seeds benefits for runners).
  • almonds, 1 ounce – 80 mg
  • spinach, 1/2 cup  – 78 mg
  • cashews, 1 ounce – 74 mg
  • peanuts, 1/4 cup  – 63 mg
  • soymilk, 1 cup  – 61 mg
  • black beans, cooked, 1/2 cup – 60 mg
  • peanut butter, 2 Tbsp – 49 mg
  • baked potato (with skin), 3.5 ounces – 43 mg
  • yogurt   8 ounces  – 42 mg

photo of magnesium rich foods

While many magnesium food sources occur in plants, the same cannot be said for collagen. If you’re looking to incorporate collagen into your diet, read our post on collagen for runners.

Magnesium Dosage for Athletes

The RDA (recommended dietary allowance) for magnesium for adults is between 300-420 mg/day. In the 19-30 age group, recommendations for females and men are 310 mg and 400 mg, respectively.

Those in the 31-50 age group have slightly higher needs, with women needing 320 mg/day and men needing 420 mg/day.

Pregnancy demands higher intakes for women as well.

Athletes may have higher needs, since strenuous exercise can increase magnesium losses through urine and sweat. Studies indicate that this may increase magnesium requirements by 10-20%.

This could be important for salty sweaters, especially, who may lose more electrolytes in sweat. 

Athletes participating in sports requiring weight control (such as wrestling or gymnastics) may be more vulnerable to an inadequate magnesium status (Source).

Focusing on magnesium in the diet or through electrolyte drinks for runners is helpful.

Do Runners Need More Magnesium?

According to research published in Magnesium Research, strenuous exercise, like running, may increase the urinary and sweat losses of magnesium and may increase magnesium requirements by 10-20%.

Magnesium deficiencies do happen. Dietary surveys lead us to believe that magnesium intakes less than 260 mg/day for males and 220 mg/day for males can lead to magnesium deficiencies.

If runners are not taking in enough calories in general or are interested in keto and running (a generally low fiber diet), they may suffer from a magnesium deficiency.

While magnesium supplementation or increased dietary intake will have beneficial effects on exercise performance in those who are deficient, magnesium supplements for runners in those with an adequate magnesium status has not been shown to enhance performance.

Similar to many supplements for runners, if you are getting adequate amounts through your diets, the benefits will be minimal, if any. The same goes for BCAAs for runners and creatine, other common options. 

See more about the differences between BCAA and creatine

blank supplement bottle

Best Magnesium for Runners

As mentioned above, if you are not deficient in magnesium, supplementation will likely not have any benefits.

However, if you are deficient or you have been instructed by your healthcare provider to take a supplement, here are some of the quality, third party tested magnesium for runner supplements we recommend.

Whether you’re looking for a slow mag for runners, or something that is easily digestible, these are your best bets. 

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  1. Institute of Medicine (IOM). Food and Nutrition Board. Dietary Reference Intakes: Calcium, Phosphorus, Magnesium, Vitamin D and Fluorideexternal link disclaimer. Washington, DC: National Academy Press, 1997.
  2. Fine KD, Santa Ana CA, Porter JL, Fordtran JS. Intestinal absorption of magnesium from food and supplements. J Clin Invest 1991;88:396-402. [PubMed abstract]
  3. Nielsen, F. H., & Lukaski, H. C. (2006). Update on the relationship between magnesium and exercise. Magnesium research19(3), 180–189.
  4. Volpe S. L. (2015). Magnesium and the Athlete. Current sports medicine reports14(4), 279–283.
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