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Give your workout a boost with magnesium

Magnesium products on pink background
Want to feel supported during every workout session? We put a H&B nutritionist through their paces to find out how magnesium could help

Our top picks

Contributes to electrolyte balance

Holland & Barrett Magnesium Bisglycinate 375mg 90 Capsules
4.69

Holland & Barrett

Holland & Barrett Magnesium Bisglycinate 375mg 90 Capsules

Buy 1 Get 1 Free

£19.29

180mg elemental magnesium per can

BetterYou Magnesium Still Water Energy (Pomegranate & Rhubarb) 4x 250ml
4.31

BetterYou

BetterYou Magnesium Still Water Energy (Pomegranate & Rhubarb) 4x 250ml

£7.50

Supports normal muscle function

Tri-Magnesium Powder Blue Raspberry 200g
4.28

Applied Nutrition

Tri-Magnesium Powder Blue Raspberry 200g

Save up to 1/2 price

£15.00

RRP £20.00

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Like calcium, potassium and sodium, magnesium is known as a macro-mineral. This means it's one of the several minerals we should all get enough of. But some of us may not be hitting our targets, which isn’t ideal for helping your body stay energised and supported during everyday movement.1

Magnesium supports muscle function and energy production," says H&B Nutritionist Madalena Vieira Costa.2 “A balanced diet should always be your main source of essential nutrients, but if you're already having a protein shake around your workout, adding a magnesium supplement can be a simple way to help make sure your magnesium levels are where you want them.”3

What does magnesium do for the body?

As Madalena explains, “Magnesium plays a role in many processes in the body, including energy production, protein synthesis, muscle function, bone health and electrolyte balance. It also supports normal bone health and contributes to calcium balance in the body.”4,5

“If magnesium levels are low, energy production may become less efficient and normal muscle and nerve function can be affected. That said, most benefits are seen when correcting an underlying magnesium deficiency. In people who already have adequate magnesium levels, taking extra magnesium is unlikely to significantly improve energy and muscle function.”6

Do I need more magnesium in summer?

Magnesium is an electrolyte, one of the mineral salts that help maintain fluid balance and normal muscle and nerve function in the body.7,8 When you lose fluids (e.g. sweating) you lose electrolytes too. You may need to replenish them if you lose a lot, which is why some people take electrolyte supplements to support hydration during exercise. So, does that mean you need more magnesium if you exercise a lot or during hot weather?

“Sweat contains several electrolytes – mainly sodium, but also smaller amounts of potassium, magnesium and calcium. However, because sweat only contains small amounts of magnesium, most people don’t automatically need extra magnesium just because the weather is hot,” Madalena explains. “Magnesium works alongside sodium and potassium to help regulate fluid balance within cells. However, sodium is the main electrolyte involved in maintaining fluid balance and supporting hydration during heat exposure.”9,10 In short, magnesium can play a part in supporting hydration, but it’s not likely to be effective all on its own.

Which foods are good sources of magnesium?

The NHS recommends that women have 270mg of magnesium a day and men 300mg, but many people in the UK aren’t getting the suggested daily amount.4 You can find magnesium in green leafy veg (like spinach), nuts and seeds, wholegrain rice and bread, avocado, dairy products and quinoa.11 Most people can get enough magnesium through a varied and balanced diet, but if you’re finding it tricky or you have certain dietary needs you may benefit from taking magnesium supplements.

Our favourite magnesium picks

Holland & Barrett Magnesium Bisglycinate 375mg 90 Capsules

Holland & Barrett

£19.29

£0.21/1 Capsule
Tri-Magnesium Powder Blue Raspberry 200g

Applied Nutrition

RRP £20.00

£15.00

£7.50/100 g

Magnesium and exercise FAQs

Should everyone take magnesium supplements?

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. See your doctor before taking magnesium supplements, though, especially if you’re pregnant or you have a health condition.
 

How do you know if your magnesium is low?

Symptoms of magnesium deficiency may include nausea, weakness, twitching, cramping or an irregular heartbeat.12 See your GP if you think you have low magnesium levels.
 

The final say

If you think your schedule’s packed, think how busy magnesium must be. It’s an essential mineral for the body, from supporting muscle function to helping reduce fatigue. To support your overall wellbeing, gym goals included, it’s important to get the recommended daily amount through a balanced diet. Next stop: which magnesium? Let’s help you choose which is best for you with our guide to the different magnesium types or debunk the myths about magnesium and sleep...
Disclaimer – This article provides informational advice and is not a substitute for medical care. Working with experts for accuracy, we take great care to ensure the information is up-to-date and relevant. However, you should always consult your GP or healthcare professional before using supplements or alternative products, particularly if you have medical conditions or are under supervision.

Sources

1. Gröber U, Werner T, Vormann J, Kisters K. Myth or Reality—Transdermal Magnesium? Nutrients. 2017 Jul 28;9(8):813.
2. Liguori S, Moretti A, Paoletta M, Gimigliano F, Iolascon G. Role of Magnesium in Skeletal Muscle Health and Neuromuscular Diseases: A Scoping Review. Int J Mol Sci [Internet]. 2024 Oct 18 [cited 2026 Apr 10]; 25(20): 11220. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC11508242/
3. 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.
4. Vitamins and minerals - Magnesium [Internet]. nhs.uk. 2017. Available from: https://www.nhs.uk/conditions/vitamins-and-minerals/others/#magnesium
5. 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/
6. Wang R et al. The effect of magnesium supplementation on muscle fitness: a meta-analysis and systematic review. Magnes Res [Internet]. 2017 Nov 1 [cited 2026 Apr 10]; 30(4): 120-32. Available from: https://pubmed.ncbi.nlm.nih.gov/29637897/
7. Shrimanker I, Bhattarai S. Electrolytes. StatPearls [Internet]. 2023 Jul 24 [cited 2026 Apr 10]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK541123/
8. National Cancer Institute (NIH). Definition – Electrolyte [Internet]. NIH [cited 2026 Apr 10]. Available from: https://www.cancer.gov/publications/dictionaries/cancer-terms/def/electrolyte
9. Baker LB et al. Exercise intensity effects on total sweat electrolyte losses and regional vs whole-body sweat [Na+], [Cl-], and [K+]. European Journal of Applied Physiology [Internet]. 2018 Dec 6 [cited 2026 Apr 10]; 119: 361-75. Available from: https://link.springer.com/article/10.1007/s00421-018-4048-z
10. Baker LB. Sweating Rate and Sweat Sodium Concentration in Athletes: A Review of Methodology and Intra/Interindividual Variability. Sports Med [Internet]. 2017 Mar 22 [cited 2026 Apr 10]; 47(Suppl 1): 111-28. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC5371639/
11. NHS. Vitamins and minerals – Others [Internet]. NHS [reviewed 2020 Aug 3; cited 2026 Apr 10]. Available from: https://www.nhs.uk/conditions/vitamins-and-minerals/others/
12. NHS. Magnesium test [Internet]. NHS [reviewed 2022 May 20; cited 2026 Apr 10]. Available from: https://www.nhs.uk/tests-and-treatments/magnesium-test/
 
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