Magnesium for athletes: recognise deficiency, improve performance

Why magnesium matters for active people

Magnesium is involved in numerous metabolic processes—including normal muscle function, the nervous system and energy-yielding metabolism. Anyone who trains regularly should therefore ensure a reliable intake.

This does not mean that more magnesium automatically leads to better performance. The greatest benefit arises when an inadequate intake is identified and corrected sensibly.

• Supports normal muscle function
• Contributes to normal energy-yielding metabolism
• Supports the normal function of the nervous system
• Is involved in many enzymatic reactions

• Volpe (2015) – Magnesium and the Athlete – Overview of magnesium functions and physical activity.

How to interpret possible signs

Muscle cramps, fatigue or poor sleep are often quickly attributed to magnesium deficiency. However, these symptoms are non-specific and can have many causes—from dehydration and high training loads to insufficient sleep.

• Recurring muscle cramps or twitching
• Persistent fatigue and unusual weakness
• Sleep problems and irritability
• Headaches or noticeably slow recovery

If symptoms occur frequently or are severe, you should seek medical advice rather than taking high-dose supplements on suspicion.

• NIH – Magnesium Fact Sheet – Reference intakes, food sources, deficiency and safety.

Magnesium, muscles and energy

Magnesium is important for muscle contraction and relaxation, as well as for reactions that provide energy in cells. An adequate intake therefore supports normal function—but an additional performance boost from supplements has not been reliably demonstrated in people who already have an adequate intake.

• Muscles: involved in normal contraction and relaxation
• Energy: important for ATP-dependent reactions
• Nerves: supports signal transmission
• Recovery: part of a balanced mineral intake

The evidence on sleep is also less clear than advertising often suggests. A low magnesium status may be relevant, but this does not support general sleep claims for everyone.

• Newhouse & Finstad (2000) – Magnesium and exercise performance – Overview: supplementation does not reliably improve performance when intake is adequate.
• Arab et al. (2023) – Magnesium and sleep – Systematic assessment of the inconsistent evidence.

Requirements and magnesium-rich foods

As general guidance, the US National Institutes of Health recommends 400–420 mg of magnesium per day for adult men and 310–320 mg per day for adult women. This does not establish a special universal target for all athletes.

• Pumpkin and sunflower seeds
• Almonds, cashews and other nuts
• Oats and wholegrain products
• Beans, lentils and chickpeas
• Spinach and other green leafy vegetables

A handful of nuts, wholegrain products and a serving of pulses or green vegetables make it much easier to meet your needs in everyday life.

• NIH – Recommended magnesium intake – Age- and sex-specific reference intakes.

Using supplements sensibly

If your diet does not meet your needs or a deficiency has been identified, a supplement may be useful. Pay attention to the actual amount of magnesium it contains, how well you tolerate it and possible interactions.

FitLine Restorate contains magnesium together with other minerals and can be incorporated into an evening routine.

• Start with a moderate amount
• Follow the current product label
• If you have a sensitive stomach, monitor your tolerance
• Consult a healthcare professional if you have a medical condition or take medication

Higher amounts of magnesium from food supplements can cause diarrhoea. More is therefore not automatically better.

Your next step

Magnesium is an essential nutrient, not a quick performance booster. First review your diet, fluid intake and overall recovery.

• Include magnesium-rich foods every day
• Do not rush to diagnose symptoms yourself
• Use supplements selectively rather than routinely
• Consider training, sleep and nutrition together

Learn more: Sports nutrition for muscle gain