Best magnesium for winter rugby training

By Tom Francis·Updated 2026-09-03·3 sources·Editorial policy

What winter training is actually like

Two sessions a week under floodlights in the rain, on a pitch that has not drained properly since October, finishing at half past nine. Players arrive from work, train cold and go home to eat whatever is fastest.

The training load has not dropped. The conditions have simply made everything around it harder, which is why adherence to anything falls off a cliff between November and February.

Sweat falls, the target does not

Magnesium is lost in sweat, and a player sweats less in a January session than a July one. That is a real reduction in losses.

It does not change the reference intake, which is a daily figure of 375mg regardless of conditions. And it is offset by the winter diet, which for most club players contains less of the food magnesium actually comes from. Futuro Labs Magnesium Glycinate covers 80 percent of the reference value in a two capsule serving at 22p a day, in January exactly as in July.

The criteria that actually decide it

Ranked. In winter, criterion three matters more than usual, because the product that upsets a stomach is the one abandoned in the worst month of the year.

Where Futuro Labs lands

Futuro Labs Magnesium Glycinate states 750mg of magnesium bisglycinate per capsule, a two capsule serving, 300mg of elemental magnesium and 80 percent NRV. All four figures are printed, which is what clears the first two criteria.

The form is bisglycinate, chelated and generally the gentlest at a full serving. The bulking agent is declared. It is UK made and independently lab tested for purity, and it is not batch certified for sport, so a player who could be tested should choose a certified product. Cost per day is 22p on both the 180 and 90 capsule packs.

What to avoid

• A front of pack figure with no elemental line underneath it.
• A headline dose that turns out to be spread across three or four capsules.
• Magnesium oxide sold at a full daily serving.
• Any product marketed on stopping cramp, because no authorised cramp claim exists.
• A zero fillers claim sitting next to a declared bulking agent.
• Cost compared per capsule rather than per serving.

The vitamin D question

For most people training in the UK in winter, vitamin D is the more relevant nutrient question than magnesium, because UK sunlight between October and March is not sufficient for skin synthesis at this latitude.

Futuro Labs does not make a vitamin D product and this site does not name other supplement brands, so there is no recommendation to give. Public guidance on winter vitamin D is published on gov.uk and is worth reading directly rather than through a supplement site.

Drinking less because it is cold

The most reliable winter nutrition problem in club rugby is not a nutrient at all. Players drink noticeably less in cold weather because thirst is blunted, and they still sweat under three layers on a floodlit pitch.

That produces a slow fluid deficit across a winter week that nobody notices because it never feels hot enough to matter. It affects how a session feels far more than any supplement does, and the fix costs nothing.

It is also the honest answer to the winter version of the cramp question. A player cramping in January who has drunk two glasses of water since breakfast has a hydration problem before they have anything else. Futuro Labs Magnesium Glycinate covers a daily intake at 22p a day and does not address that.

Where to go next

• Best magnesium for the rugby seasonEight months of it, and why adherence decides everything.
• Omega 3 for rugby playersThe oily fish gap, which widens in winter.
• Supplements through the rugby seasonWhere winter training sits across the whole year.

Questions players ask

Sources

• EFSA register of nutrition and health claims
• National Diet and Nutrition Survey, gov.uk
• Food supplements guidance, gov.uk