Like calcium, potassium and sodium, magnesium is known as a macro-mineral. This means it's one of the six essential minerals we all need to get enough of every day. But many of us aren’t hitting our targets,¹ which is bad news for our bodies and brains – let alone our workouts.

“Magnesium supports muscle function and energy production and,"² says H&B Nutritionist Madalena Vieira Costa, adding how essential these are to exercise. She points out what a team player it is when it comes to your gym-going diet: "If you’re already having a protein shake, a magnesium supplement could help your body make the best of the extra protein intake.”³

So, how can you make sure your magnesium levels are where you want them? And how can it support your sport performance? Let's find out together.

What can magnesium do for you?

Loads! Magnesium is needed for more than 300 reactions in your body, including turning your food into energy, normal muscle function, the uptake of oxygen, and the balance of electrolytes. It can support the maintenance of normal bones as it allows our bones to absorb calcium efficiently – and can help maintain the health of our muscles too.^4,5

“The same recommended daily amount (300mg a day for men and 270mg a day for women) applies, whether you're exercising or not. But magnesium is definitely one to ensure you’re getting in your diet or with supplements, as a lack of magnesium could be impacting your overall wellbeing and performance,” Madalena says.

We gathered eight magnesium myths to help you navigate this macro-mineral even more.

How can magnesium support sports performance?

Magnesium supports your muscles by helping to replenish their energy stores. A review of published studies by Indiana University in 2017 found that the body’s need for magnesium increases the more you exercise.⁶

Madalena also shares first-hand how magnesium alongside rehydrating has helped her balance her electrolytes post-exercise: “I find electrolyte drinks containing sodium, potassium, magnesium and calcium can really help your overall wellness.”

“Magnesium losses via sweat are relatively low. However, due to its electrolyte balance property, it can help up your electrolytes again.”

Can magnesium support muscles?

“As magnesium supports normal muscle function, having a good daily intake can help the maintenance of normal bones,” Madalena suggests. “As it’s an essential mineral, it can also benefit your bone and muscle health.”

“Soaking in a bath of magnesium salts is also a great way to relax on a rest day, since the combination of warm water and magnesium can help muscle relaxation and enhanced circulation, leading to improved sleep.”

So that’s what our expert has to say — but how can you add more magnesium to your plate?

Good sources of magnesium

The NHS recommends that women have 270mg of magnesium a day and men 300mg,⁴ but research has found that many people in the UK aren’t getting the suggested daily amount.⁷

You can find magnesium in:

green leafy vegetables, such as spinach
nuts and seeds
brown rice bread, especially wholegrain
oily fish
yoghurt and other dairy products
avocado
quinoa
and even… dark chocolate

Be careful not to consume too much magnesium as excessive amounts can cause side effects, including an upset stomach.

The final say

If you think your workout schedule is packed, think how busy magnesium must be. It’s an essential mineral for how your body works – from building muscle to replenishing your energy. So, if you’re hoping for results in the gym, ensure you’re hitting the RDA through a healthy, balanced diet.

If you don’t have a magnesium deficiency, there’s no need to take extra supplements. And as for magnesium bath salts, they’re the perfect way to relax on a rest day.

Next stop: which magnesium? Let’s help you choose which is best for you with our guide to the different magnesium types.

Disclaimer

The advice in this article is for information only and some of the information reflects the opinion of our in-house nutritionist and should not replace medical care. Please check with your GP or healthcare professional before trying any supplements, treatments or remedies. Food supplements must not be used as a substitute for a varied and balanced diet and a healthy lifestyle.

Sources

Gröber U, Werner T, Vormann J, Kisters K. Myth or Reality—Transdermal Magnesium? Nutrients. 2017 Jul 28;9(8):813.
National Institutes of Health. Office of Dietary Supplements - Magnesium [Internet]. National Institutes of Health. 2022. Available from: https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/
Carolina A, Añdrea Rodrigues Vasconcelos, Denise Deo Dias, Geovana Komoni, José João Name. The Integral Role of Magnesium in Muscle Integrity and Aging: A Comprehensive Review. Nutrients. 2023 Dec 16;15(24):5127–7.
Vitamins and minerals - Magnesium [Internet]. nhs.uk. 2017. Available from: https://www.nhs.uk/conditions/vitamins-and-minerals/others/#magnesium
Castiglioni S, Cazzaniga A, Albisetti W, Maier J. Magnesium and Osteoporosis: Current State of Knowledge and Future Research Directions. Nutrients [Internet]. 2013 Jul 31;5(8):3022–33. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3775240/
Zhang Y, Xun P, Wang R, Mao L, He K. Can Magnesium Enhance Exercise Performance? Nutrients [Internet]. 2017 Aug 28 [cited 2019 Jul 16];9(9):946. Available from: https://www.mdpi.com/2072-6643/9/9/946/htm
Derbyshire E. Micronutrient Intakes of British Adults Across Mid-Life: A Secondary Analysis of the UK National Diet and Nutrition Survey. Frontiers in Nutrition. 2018 Jul 19;5(55).

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