Is magnesium good for muscle strength?

The strength evidence by population, because the same supplement did four different things in four different groups

Is magnesium good for muscle strength is answered by the strength evidence sorted by who was studied, because the same supplement did four different things in four populations and the sort reveals the pattern. Elderly women with low dietary intake: the clearest strength trial gave 300mg of magnesium daily, as oxide, to healthy elderly women in a weekly exercise programme for twelve weeks and found improved physical performance, chair-stand time, walking speed and a composite score, against placebo, with the effect concentrated in the women whose dietary magnesium intake was below the reference, a population in which strength and function are limited by many things and a magnesium shortfall was one of them. Untrained novices: the small 1992 trial gave magnesium at a body-weight-scaled dose to untrained subjects starting a strength programme and reported greater leg-strength gains than placebo over seven weeks, in people whose novice gains were large on any programme and whose status was not established, a suggestive result never replicated. Athletes with marginal status: the volleyball trial measured status, found it marginal, supplemented, and found improved jumping and other performance markers, the athletes flagship's clean example of repletion improving performance where status was low. Trained lifters with adequate status: the independent ZMA replication gave 450mg of magnesium and 30mg of zinc daily to trained men through eight weeks of resistance training and found no effect on strength, body composition or hormones, the cleanest test of adding magnesium to men who had enough. Four populations, four results, and the exercise reviews summarise them as an association between status and performance in cross-sectional data and an effect of supplementation only where status was low.

The pattern that runs through all four, what it means for a lifter, and the question filed

The pattern is repletion rather than enhancement, and it is the same pattern every mineral page here finds: where a shortfall was costing strength or function, elderly women eating little magnesium, athletes with marginal status, possibly the novices, repletion restored what the shortfall cost, and where status was adequate, trained lifters eating well, more magnesium did nothing, because a replete cofactor is met and surplus is excreted rather than stored in muscle, the build-muscle page's necessary-not-sufficient teach in its strength form. The mechanism fits: strength is force generated by contraction, contraction spends magnesium-ATP at the myosin head and the pumps, and a fibre short of its cofactor generates force less well, the shortfall showing first as fatigue and cramps and, at the extreme, as the weakness of hypomagnesaemia, while a fibre with its cofactor generates the force its training built and no more. What it means for a lifter is the diet audit: a lifter on a protein-heavy diet light in greens, nuts, seeds, legumes and wholegrains, on a cut or a rice-and-chicken bulk, is in the population the pattern helps, and 300mg elemental as bisglycinate daily restores whatever a shortfall was costing over four to eight weeks; a lifter eating a mixed diet is in the population the pattern does not help, and gains nothing from the capsule; and neither lifter gets strength from magnesium beyond their own trained normal, strength itself belonging to the progressive stimulus, protein, energy and sleep. Is magnesium good for muscle strength, then: good where a shortfall was costing it, in the sense the elderly-women and marginal-athlete trials show, neutral where it was not, in the sense the trained-lifter trial shows, and never a strength enhancer, with the register's muscle-function sentence describing the maintenance of a replete cofactor. The question filed: strength by population, repletion as the pattern, and the worked example for the lifter who runs short, 300mg elemental at 22p, £19.99 for 90 days.

The verdict, good for strength where a shortfall was costing it

Is magnesium good for muscle strength: good where a shortfall was costing it, the elderly-women trial improving chair-stand and walking on 300mg daily with the effect concentrated in low intake, the marginal-status athletes improving performance markers and the novice trial suggesting more, and neutral where status was adequate, the trained-lifter trial finding nothing, the pattern being repletion rather than enhancement because a replete cofactor is met and surplus is excreted, so that a lifter's diet audit decides which population they are in and strength itself belongs to the stimulus, protein, energy and sleep. For the lifter who runs short: Futuro Labs Magnesium Glycinate, bisglycinate, 300mg elemental at 80% NRV, £19.99 for 90 days at 22p a day.

What to check on the label

Questions people also ask

Does magnesium make you stronger?

Not above your own trained normal: the trials show repletion restoring strength and function where a shortfall was costing them, in elderly women with low intake and athletes with marginal status, and nothing in trained lifters with adequate status.

What is the best evidence that magnesium helps physical performance?

A twelve-week randomised trial in healthy elderly women in an exercise programme, where 300mg of magnesium daily improved chair-stand time and walking speed against placebo, with the effect concentrated in women whose dietary intake was below the reference.

Did magnesium improve strength in trained lifters?

No: the independent ZMA replication gave 450mg of magnesium and 30mg of zinc daily to trained men through eight weeks of resistance training and found no effect on strength, body composition or hormones, the cleanest test in men who had enough.

Why would magnesium affect strength at all?

Contraction spends magnesium-ATP at the myosin head and the calcium pumps, so a fibre short of its cofactor generates force less well, showing first as fatigue and cramps, while a replete fibre generates the force its training built and gains nothing from more.

Should a lifter take magnesium for strength?

Only by audit: a lifter on a cut or a rice-and-chicken bulk whose diet runs light is in the population repletion helps and takes 300mg elemental as bisglycinate daily, while a lifter on a mixed diet is replete and gains nothing, strength belonging to the stimulus, protein, energy and sleep.

Sources

1. Veronese N, et al. Effect of oral magnesium supplementation on physical performance in healthy elderly women involved in a weekly exercise program: a randomized controlled trial. American Journal of Clinical Nutrition 2014;100(3):974-981: 300mg of magnesium oxide daily for twelve weeks improved chair-stand and walking performance in elderly women, an effect concentrated in those with low dietary intake. PubMed record
2. Brilla LR, Haley TF. Effect of magnesium supplementation on strength training in humans. Journal of the American College of Nutrition 1992;11(3):326-329: a small trial in untrained subjects reporting greater strength gains with magnesium, not replicated in trained athletes. PubMed record
3. 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
4. Wilborn CD, et al. Effects of zinc magnesium aspartate (ZMA) supplementation on training adaptations and markers of anabolism and catabolism. Journal of the International Society of Sports Nutrition 2004;1(2):12-20. PubMed record

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