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How much magnesium for athletes?
Athletes should take 300mg elemental magnesium a day from a supplement, on top of food: the UK reference intake, under the 400mg supplement guidance level, beside the 350mg the trials used. More adds laxative effect, not performance.
- 300mgelemental a day from a supplement, the athlete's dose
- 400mgthe UK guidance level for supplements
- 350mga day in the positive athlete trials
- 22pa day at the worked example's price
The worked example throughout: Futuro Labs Magnesium Glycinate on Amazon UK, 300mg elemental per 2 capsules, £19.99 for 90 days. Label breakdown.
How much magnesium per day, before training enters it
The UK reference nutrient intake is 300mg a day for men and 270mg for women, set by the COMA panel, and the labelling reference value that %NRV figures point at is 375mg. Those numbers describe total intake from everything, and a diet with green vegetables, nuts, seeds, beans and wholegrains can meet them unaided. The supplement question begins where the diet or the training says otherwise.
How much magnesium should you take for the gym and weightlifting?
300mg of elemental magnesium a day from the supplement, on top of food. Training raises losses through sweat and urine, which Nielsen and Lukaski's review documents in hard-training athletes, and the lifter's default diet is poor in magnesium, so the supplement's job is to guarantee the reference intake is met on every day of a block. One serving of the worked example does exactly that: 2 capsules, 1500mg bisglycinate at 20%, 300mg elemental, 80% NRV.
What is the magnesium bodybuilding dosage the trials support?
The trials that found benefits in athletes used 350mg a day: Setaro's 2014 volleyball study reported better jump performance after four weeks, and Reno's 2022 study reported less soreness around a strenuous session after ten days. Zhang's 2017 review ties those benefits to correcting a low intake. A 300mg supplemental dose on top of food lands in that territory without paperwork; there is no separate bodybuilding dose, and the bigger physique does not change the ceiling, because the guidance level is about the gut, not bodyweight.
How much magnesium glycinate should you take daily, in capsules?
Whatever your product's panel says delivers 300mg elemental. On the worked example that is 2 capsules once daily with a meal; on compound-labelled products it can be six or more, which is the label trap covered across this site. One capsule, 150mg elemental, is the honest top-up when the diet nearly covers the reference intake. Bisglycinate and glycinate dosage are the same question, because they are the same material.
Is there an upper limit, and does food count toward it?
The Expert Group on Vitamins and Minerals set a guidance level of 400mg a day for supplemental magnesium, based on the laxative effect that appears above it in some people; it applies to supplements and fortified sources, not to food, because magnesium in food arrives slowly and bound up with everything else. So a big diet plus a 300mg supplement is fine, and a 300mg supplement plus a 200mg citrate topper is over the line. Doses above 400mg belong to clinicians treating measured deficiency, and the 10mg per kilogram used in Cinar's testosterone study, about 800mg for an 80kg lifter, was a research protocol, not a recommendation.
Should you split the dose or take it at once?
At 300mg from glycinate, one dose with the evening or post-training meal is fine and is the habit that survives; the low laxative effect is the reason the form was chosen. Splitting, 150mg morning and evening, marginally improves absorption fraction and suits sensitive stomachs, and matters more for citrate, where a full single dose is what loosens the bowel. There is no timing effect on performance either way, because magnesium has no acute action.
| Dose | What it is | Verdict for an athlete |
|---|---|---|
| 150mg elemental (1 capsule) | Top-up on a near-complete diet | Fine; the honest half dose |
| 270mg to 300mg | UK reference intakes for women and men | The daily target from all sources |
| 300mg supplemental | The worked example's serving | The athlete's dose: reference intake guaranteed, under the ceiling |
| 350mg | The positive athlete trials | Where the evidence sits; 300mg supplemental plus food reaches it |
| 400mg supplemental | UK guidance level (EVM) | The ceiling; above it the laxative effect arrives first |
| 500mg | Abbasi's sleep trial in older adults | A research dose; not for unsupervised daily use |
| 800mg (10mg per kg) | Cinar's four-week testosterone study | Research only; double the guidance level |
| 1000mg or more | Internet numbers | No; covered on its own page |
The worked example, priced
Futuro Labs Magnesium Glycinate delivers the athlete's dose as designed: 300mg elemental per 2 capsules, 80% NRV, from 1500mg bisglycinate at 20%, vegan HPMC capsules, made in the UK under GMP and BRC certification, third-party heavy metal and microbiology panels shown, 180 capsules for £19.99, which is 90 days at 22p, or the £9.99 pouch of 90 at the same rate. Take it with the evening meal every day of the block, rest days included, and hold the dose rather than chasing a bigger number; how much magnesium for athletes is a question the UK figures already answered, and 300mg is it.
What to check on the label
- 300mg elemental a day from the supplement, on top of food, rest days included.
- Under 400mg supplemental total if a second form is running.
- The panel decides the capsules: 2 on the worked example, more on compound labels.
- No bodyweight scaling: the ceiling is about the gut, not the physique.
- Research doses left to research: 500mg and up are not daily-use numbers.
The worked example: Futuro Labs Magnesium Glycinate
Futuro Labs Magnesium Glycinate is the dose done for you: 300mg elemental per 2 capsules (80% NRV), one serving a day with a meal, vegan, UK made, panels shown, 22p a day from a £19.99 bottle of 180.
- Elemental magnesium per serving
- 300mg (80% NRV)
- Form
- magnesium bisglycinate 20%
- Serving
- 2 capsules a day
- Bottle
- 180 capsules, 90 days
- Price
- £19.99 (22p a day)
- Capsule
- vegetarian shell, vegan product
Questions people also ask
How much magnesium should I take for weightlifting?
300mg elemental a day from a supplement on top of food. The positive trials used 350mg; the UK supplement ceiling is 400mg.
How much magnesium glycinate should I take daily?
Whatever delivers 300mg elemental; on Futuro Labs Magnesium Glycinate that is 2 capsules once daily with a meal.
How much magnesium do bodybuilders take?
The sensible ones take the same 300mg elemental; there is no bodybuilding dose, and the 400mg guidance level does not scale with size.
How much magnesium bisglycinate per day?
Bisglycinate and glycinate are the same material: 1500mg of a 20% bisglycinate gives the 300mg elemental target.
Can I take 500mg of magnesium daily?
It exceeds the UK supplement guidance level of 400mg. The 500mg figure comes from a supervised trial in older adults, not a daily-use recommendation.
How much magnesium per day in the UK?
300mg for men and 270mg for women from all sources; a 300mg elemental supplement guarantees it for someone training on a narrow diet.
Should I take magnesium every day or just training days?
Every day. Intake is a daily figure and losses continue between sessions; the trials all dosed daily.
Sources
- Futuro Labs Magnesium Glycinate listing, Amazon UK, label and price checked 31 August 2026. https://www.amazon.co.uk/dp/B0BT7Z5VQW
- Department of Health. Dietary Reference Values for Food Energy and Nutrients for the United Kingdom. Report on Health and Social Subjects 41, 1991 (magnesium RNI 300mg men, 270mg women).
- Retained Regulation (EU) No 1169/2011, Annex XIII: nutrient reference value for magnesium 375mg. https://www.legislation.gov.uk/eur/2011/1169/annex/XIII
- Expert Group on Vitamins and Minerals. Safe Upper Levels for Vitamins and Minerals. Food Standards Agency, 2003 (magnesium guidance level 400mg a day from supplements). https://cot.food.gov.uk/sites/default/files/vitmin2003.pdf
- Setaro L, et al. Magnesium status and the physical performance of volleyball players: effects of magnesium supplementation. Journal of Sports Sciences 2014;32(5):438-445. PubMed record
- Reno AM, Green M, Killen LG, O'Neal EK, Pritchett K, Hanson Z. Effects of magnesium supplementation on muscle soreness and performance. Journal of Strength and Conditioning Research 2022;36(8):2198-2203. PubMed record
- Zhang Y, Xun P, Wang R, Mao L, He K. Can magnesium enhance exercise performance? Nutrients 2017;9(9):946. https://pubmed.ncbi.nlm.nih.gov/28846654/
- Nielsen FH, Lukaski HC. Update on the relationship between magnesium and exercise. Magnesium Research 2006;19(3):180-189. PubMed record
- Abbasi B, et al. The effect of magnesium supplementation on primary insomnia in elderly: a double-blind placebo-controlled clinical trial. Journal of Research in Medical Sciences 2012;17(12):1161-1169. PubMed record
- Cinar V, Polat Y, Baltaci AK, Mogulkoc R. Effects of magnesium supplementation on testosterone levels of athletes and sedentary subjects at rest and after exhaustion. Biological Trace Element Research 2011;140(1):18-23. PubMed record
- EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to magnesium. EFSA Journal 2010;8(10):1807. https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2010.1807