Magnesium Deficiency Can Leave Runners Feeling Tired

Dear A & H…Even though today’s topic’s a bit grim, magnesium deficiency, I’m pumped it involves nutrition. It’s such a little talked about micronutrient but possibly the reason why most of us aren’t firing on all cylinders. 😲  

How Magnesium Works…But, First, A Little Perspective

Imagine getting the opportunity to spend the day cruising down the coast in the raddest, baddest, most envy-worthy convertible known to man, the limited edition Stickhugger 360.

Your beyond giddy knowing you have a full tank of premium grade gas, a full day…an actual 24 hours!!!…and no commitments.

Gosh darn, you’re going to milk that puppy for all it’s worth!

With that, you hop into your dream car and crank the engine.

(Cricket chirping silence.)

You turn the key again…

Nothing.

No sound, no sputter…nothing.

Is this some sick joke?!?

Quick as a whip you jump out of the car, pop the hood, and frantically search for the problem.

Then you spot it…What the…?

Who would do such a thing?

It just doesn’t make sense.

No spark plugs?

Weird…everything seems to be taken care of…not a single bolt neglected…

Who would maintain such a fine machine and leave out the spark plugs!?!

Who, indeed.

If You’re Reading This, You’re Likely Magnesium Deficient

As runners, are we similarly sabotaging our own machines, our bodies, when we fail to meet our nutritional needs for magnesium?^1,2

A valid question since it’s estimated that a good portion of the population, nearly two-thirds of the population in the western world,³ is likely deficient in this mineral. Since runners are a part of this population, its likely sub-optimal magnesium intake to meet bodily demands is affecting not only our efforts during training but also while competing.

Why’s this?

It’s because, similar to spark plugs, magnesium serves a pivotal role in the cellullar reactions that make energy. It’s a cog in the machine that, when not available in sufficient amounts, can leave us feeling tired.

An Aside

As you likely know, besides magnesium deficiency, there are a whole host of reasons why we might feel tired or lack energy. Here are a few others:⁴

• iron-deficiency anemia
• poor sleep hygiene/sleep apnea
• depression
• menopause
• diabetes
• heart problems
• thyroid issues
• etc.

This list underlines why it’s so difficult zeroing in on why we feel crummy.

In addition, feeling crummy might not be the result of only one issue, but many. ☹️

Anyway, back to magnesium…

What’s Magnesium?

It’s atomic number 12 on the Periodic table and the fourth most abundant mineral in our body. The latter quality, abundance, is not only impressive in its own right but foretelling since magnesium is involved in more than 300 cellular reactions in our body.⁵

These include reactions that regulate (and, mind you, this is not a full list):

• blood pressure
• muscle and nerve function
• protein synthesis
• bone development
• AND…very important to runners…the metabolism of food components to produce energy.⁶

The Mitochondria…Where Magnesium Does Its Magic 

With regard to that last role, producing energy, magnesium (Mg2+) is the figurative “spark plug” which helps convert energy stored in food into a form useful to do “work.” Unfortunately, it’s not as direct a route as this sounds but, for all its taxing complexity, it’s spectacular…

In the interest of brevity, a simplified explanation for all these reactions is this: Food (i.e. carbs and fat), once eaten, digested, absorbed, and transported to the mitochondria in cells, gets processed into ATP, a desirable end-product because of energy stored within its molecular bonds, useful energy to do stuff like run a half-marathon.

For all this to happen efficiently, though, magnesium needs to be around in sufficient amounts. It’s the *oomph* ATP needs^6,7,8 to release its much-desired energy.

Note: While this role can also be fulfilled by calcium (Ca2+) and manganese (Mn2+), our body prefers magnesium.⁹ Kind of like many things in life. Sometimes one choice stands head and shoulders above the rest. Take sleep surfaces, for example. If given a choice between the ground, a cot, or a mattress, one will likely lead to better sleep than the others.

But what happens when magnesium is in short supply?

Could feelings of fatigue and weakness be a legitimate sign of lack of magnesium?

Prevalence of Magnesium Deficiency

As this table shows, the magnitude of insufficient magnesium intake is concerning (as well as other nutrients…☹️), especially considering how vital it is to so many of our body’s cellular reactions.

Yet, for athletes, while some scientific studies suggest we fall short of our dietary needs for magnesium^1,10 , others say we are likely meeting needs.^11,12

Huh?

Yep, so it goes with scientific data based on self-reported intakes, no matter if the data is based on dietary recall or food diaries, variability comes about from the simple fact that we’re sensitive about owning up to what we eat, drink, snack on, etc. How this affects intake data is underestimating the consumption of food and beverages perceived as “bad” and overestimating what’s perceived as healthy.^6,13,14,15

With this in mind, if we report we’re eating better than we are, it’s not illogical to think the percentages of us failing to meet our need for magnesium is actually higher than the 50% of the population the table above suggests, maybe even as high as 80%.

In any case, with statistics pointing to how prevalent magnesium insufficiency is, it’s likely that you, a neighbor, and the person standing next to you in line at the grocery store are likely deficient in this vital nutrient without you even knowing it.

Which begs the question, what’s the cause behind this overlooked but concerning micronutrient deficiency?

What Causes Magnesium Deficiency in Otherwise Healthy Runners?

For a healthy runner who is careful about the food they put in their mouth and is otherwise healthy, the causes for a deficiency can be narrowed down to:

• poor intake and
• increased loss or need.

To see if any of the above applies to you, let’s explore each a little more closely.

Magnesium Deficiency Due to Poor Intake

Food

Magnesium-rich foods are those that can also be called whole and unrefined, the leafy greens, whole grains, nuts, seeds, and legumes that we sometimes walk by at the grocery store.

So it goes…

Life is busy and, oftentimes, we just want our foot to be easy…not having to stand in the kitchen for an hour making dinner is easily solved by buying prepared or semi-prepared meals.

No harm in that reasoning, yet, as we rely more and more on convenience, are we unconsciously chipping away at our health as more and more foods lacking key nutrients, like magnesium, start to make up the bulk of our diets?

You might say that you’re not part of this group but, ask yourself, do you regularly consume more of the following than you’d like to admit:

• coffee and/or soda^6,16,17
• alcohol^6,17
• fried foods/saturated fat¹⁷
• sugar^18,19 (cough, cough…😬)

If you answered “yes,” there’s definitely room for improvement in your dietary habits.

If you answered “no,” you’re still not out of the woods.

For many health-conscious eaters, our best intentions at eating well could be hindered by a factor out of our control.

Today’s dirt is not yesterday’s dirt. Soil depletion is a real problem today, leading to produce with much less nutritional value than the fruits and vegetables our grandparents ate just a few decades ago. So, while modern intensive agricultural methods strive to increase reliable yields per parcel of land, this can lead to crops with lowered nutritional value²⁰ as this statistic points out²⁰:

Water

Outside of food habits, water, which can be a good source of magnesium, takes a hit depending on where it’s sourced or if it’s softened.

Tap water coming from surface water is lower in magnesium content than water sourced from groundwater. Groundwater, due to the nature of its travels, percolates through minerals containing calcium and magnesium making it “hard” and, unlike surface water, mineral-rich.²¹

For those who choose or need to soften their water, this can drop magnesium content to as low as zero.²¹

As for bottled water, magnesium content varies greatly, ranging from zero to a rather good magnesium source, meeting up to 1/4 to 1/3 the Recommended Dietary Allowance (RDA) for adults per liter. For this reason, consumers of bottled water who desire minerals with their hydration need to read labels to find which brands contain minerals such as magnesium.²²

Magnesium Deficiency Due to Increased Loss or Need¹⁷

Phytates and Oxalates^23,24

These are naturally occurring compounds in plants that play a role in providing energy for sprouting seeds (phytates) and imparting a bitter taste to dissuade eating by predators (oxalates).

Foods with the most phytate content include whole grains, legumes, nuts, and seeds.

Foods with the most oxalate content include spinach, greens (beet, chard, collards, kale), rhubarb, cocoa, black tea, peanuts, beans, sweet potatoes, bran flakes, potatoes, etc.

These two compounds are concerning because of their ability to bind magnesium and prevent it from being absorbed. Fortunately, soaking and cooking helps reduce their content in food.^25,26

It’s important to note that, in spite of their ability to bind minerals like magnesium, phytates and oxalates are not bad. They have qualities that impact our health positively, too. Concerning phytates, clinical studies suggest a protective effect against cancer through affecting our immune system,²⁶ They also help reduce cholesterol and inhibit dental caries.²⁵ As for oxalates, they’re associated with reducing cancer risk.²⁷

Leaky Gut

This condition results when the wall of the small intestine is damaged by such causes as:^28,29

• food allergies
• excessive use of aspirin or ibuprofen
• antibiotics
• excessive use of alcohol
• bacterial imbalance in the gut (dysbiosis).

Though not completely embraced as a condition by the medical community, leaky gut can cause malabsorption of magnesium as well as other minerals.³⁰

Use of Proton-Pump Inhibitors

Prescription proton pump inhibitor (PPI) drugs, such as Nexium and Prevacid, can lead to magnesium deficiency when used for more than a year. Once lowered, magnesium supplements can improve levels for those who show deficiency except, for about 25% of these people, their only recourse is stopping the use of PPIs.^31.32

Aging

As we get older, intestines and kidneys are less efficient at metabolizing magnesium. What this amount to are intestines less capable of absorbing this vital nutrient and increased loss in urine. Add to this a diet poor in magnesium and you’ve got the makings for a potential deficiency.^31,33-34

Stress

Stress in all forms, whether physical (i.e. exertion, heat, cold, accidental trauma, surgical trauma, burns) or emotional (i.e. pain, anxiety, excitement, depression), increases our need for Mg.^17,37

Sweat and Urine

Strenuous exercise seems to increase our need for so many things. Not only do we need more calories and sleep, we might need up to 10-20% more magnesium because of increased loss through urine and sweat.^2,6,17

High Intake of  Protein, Calcium, Vitamin D, and/or Alcohol

Excessive intake of protein, calcium, vitamin D, and/or alcohol all conspire to keep us from retaining magnesium or increasing our requirement for it, especially for those of us with a magnesium-poor diet..^35,36

Excessive Menstruation¹⁷

As iron is lost in menstrual blood, so is the fate of other minerals such as magnesium.

Summing Up

Magnesium deficiency, whether created from choices under our control or not, is a condition of much concern for any athlete, especially runners, who depend on their dietary choices to be a reliable energy source.

Yet, if magnesium is not available in adequate amounts at the cellular level, no matter our good intentions with eating well and trying to live as healthy a life as we can, all these noble efforts will only do so much to alleviate our collective lack of energy.

Thankfully, magnesium deficiency, whether mild or more pronounced, is a correctable condition.

While this is reassuring, I’d caution against the knee-jerk solution to just opt for a bottle of magnesium pills. While this has its merits, which I’ll explore in my next post, the most beneficial option is one that will not only serve you now but for years and years to come.

Quite possibly, you already know what this is.

I can already hear the groaning. 🙂

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So, A & H, this post was a big project. One of the best parts was discovering how to toggle my sources. Now it’s time to celebrate with my favorite meal, pesto on a bed of greens. Must set a good example for the one or two people who read my posts. Hehe. ت  Until my next letter…

Much love, O.M.