Does running deplete magnesium?

There is some evidence that strenuous exercise may increase magnesium losses in sweat and urine by 10-20% [

1

]. Although the research on magnesium depletion and running is lacking, it can be assumed that high mileage may lead to some magnesium depletion. 

A magnesium intake less than 260 mg/day 220 mg/day for male and female athletes, respectively, may result in a magnesium-deficient status [

1

]. Evidence suggests that magnesium supplementation or increased dietary intake of magnesium may have beneficial effects on exercise performance in magnesium-deficient individuals.