Magnesium for athletes: useful or usually unnecessary?

Short answer

Magnesium is important for muscle and nerve function, among other things. That does not mean extra magnesium makes every athlete stronger or prevents every muscle cramp. ^[1]

Correcting a shortfall is different from taking extra

Nuts, pulses, wholegrain products and green leafy vegetables provide magnesium. A supplement can be relevant if your intake is inadequate or in a specific medical situation, but assess your diet and any complaints first. ^[1]

A review of research on muscle soreness reports favourable results in a few studies. However, the limited research base does not justify a guarantee of better recovery for every athlete. Moreover, muscle soreness after training is different from cramp during exercise. ^[2]

More is not automatically better

Magnesium from supplements can cause diarrhoea, nausea and abdominal cramps. With kidney problems, the risk of build-up can increase; interactions with medicines also deserve attention. ^[1] So do not take several products at once without checking the total amount.

In practice

Do not use a cramp or a tiring session as a self-diagnosis of magnesium deficiency. With recurring complaints, it is wiser to have the cause assessed than to keep trying a higher dose.