Magnesium supports hundreds of enzymes in the body, including those involved in muscle function, nerve signalling, and sleep regulation. Many UK adults do not hit recommended intakes from food alone-especially if training hard increases losses through sweat.
Common magnesium forms
- Glycinate / bisglycinate - often chosen for evening use and general tolerance
- Citrate - well absorbed; can have a mild laxative effect at higher doses
- Oxide - cheaper but lower absorption; less ideal if absorption is the priority
- Malate - sometimes used for energy metabolism support
How much magnesium?
UK reference nutrient intake for adults is roughly 300 mg (women) and 375 mg (men) per day from all sources. Supplement doses often range from 200-400 mg elemental magnesium-check the label for elemental amount, not just total compound weight.
Start low, especially with citrate, to see how your digestion responds.
Sleep and recovery: realistic expectations
Magnesium is not a sedative. Some people report calmer evenings or easier sleep onset when they were borderline deficient. Pair supplementation with:
- Consistent sleep and wake times
- Protein intake spread across the day
- Hydration and electrolytes after heavy sessions
Training and electrolytes
Hard sessions increase sweat losses. Magnesium works alongside sodium and potassium in hydration and electrolyte products for longer or hot sessions.
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Browse our magnesium supplements and wider vitamins & minerals range.
Supplements can interact with medicines (including some antibiotics and thyroid medication). Ask a pharmacist or GP if unsure.