Magnesium is an electrolyte that has been praised for everything from better sleep to boosted athletic performance. This might make you wonder if you’re consuming enough of it, especially considering you lose electrolytes through sweat.
As a runner, you want to consume enough magnesium so your body can make protein, conduct muscle and nerve functions, regulate blood sugar and blood pressure levels and produce energy. Magnesium may also support your circadian rhythm, a.k.a. your sleep and wake pattern. The body also needs this electrolyte to help with the activation of vitamin D, a key nutrient needed for bone health.
'After puberty, we’re done growing, but even up until age 30, female athletes in particular, are still developing their peak bone mass density,' says Kate Patton, registered dietitian for the Cleveland Clinic’s Digestive Disease and Surgery Institute. Along with vitamin D and calcium, your body needs magnesium to build strong bones, so if you’re low in any of these nutrients you could be at higher risk for stress fractures, or aches and pains like shin splints, she adds.
Unfortunately, '[some] athletes actually have very low magnesium levels, despite supplementation,' says Michael Yang, M.D., a sports medicine physician at Jefferson Health. Elite-level runners in particular are more likely to have lower levels of magnesium – as opposed to the typical recreational runner – because they tend to exercise more and drink more fluids, so they’re filtering more magnesium through the kidneys, Yang explains.
To find out if you need more magnesium, doctors can test your levels with a blood or urine sample at your request. But you can also keep an eye out for these symptoms of magnesium deficiency, and pay attention to your intake with the strategies below.
What are the symptoms of magnesium deficiency?
While a magnesium deficiency often doesn’t show clear signs, you may experience the following according to Patton and Yang:
Early symptoms:
- Fatigue or low energy
- Nausea
- Loss of appetite, which can lead to vomiting
- Slower recovery time
More serious symptoms:
- Muscle spasms
- Numbness
- Decreased immune system function
- Heart arrhythmia
- Other heart issues like plaque formation in heart blood vessels, which can lead to a heart attack
- Low blood pressure
How much magnesium do you need?
According to the NHS, the amount of magnesium you need is:
- 300mg a day for men (19 to 64 years)
- 270mg a day for women (19 to 64 years)
For adults over age 51, it's particularly important to ensure you're consuming enough magnesium, as your body’s ability to absorb the nutrient decreases as we get older, and we tend to excrete more of it, says Patton.
What are the best sources of magnesium?
*Magnesium numbers per serving size, according to the NIH
- 28g roasted pumpkin seeds: 156mg
- 28g chia seeds: 111mg
- 28g roasted almonds: 80mg
- 62.5g spinach, boiled: 78 mg
- 28g roasted cashews: 74 mg
- 62.5g cup black beans, cooked: 60 mg
- 62.5g cup edamame: 50 mg
- 2 tbsp peanut butter: 49 mg
- 22g low-fat, plain yogurt: 42 mg
- 1 medium banana: 32 mg
- 85g cooked salmon: 26 mg
- 85g roasted chicken breast: 22 mg
Should you consider taking a magnesium supplement?
Whole foods are the best sources of magnesium, so if you have a good balanced diet that consists of fruits, vegetables, whole grains, seeds, and a variety of protein, or you take a multivitamin with minerals including magnesium, then you don’t have to worry about supplementation, says Patton.
Magnesium supplements comes in a variety of different forms. Though magnesium citrate is the most common form, it tends to have a laxative effect; magnesium glycinate is an alternative that’s commonly used to improve sleep and is easier on the digestive tract, Patton explains.
If you’ve been diagnosed with magnesium deficiency and are interested in supplementation, Patton recommends selecting a product that’s been certified by the National Sanitation Foundation (NSF), an independent third-party program that tests supplements, cosmetics and personal care products for the health and safety of consumers.
If you take magnesium supplements, do not take too much as this could be harmful.
Having 400mg or less a day of magnesium from supplements is unlikely to cause any harm.
