Iron can improve physical and cognitive performance

June 14, 2009

Female soldiers given iron supplements improved scores for running tests and cognitive performance, according to US study.

In a randomized controlled trial, 219 female US soldiers in an eight-week basic combat training received either a placebo or supplements containing 100 mg ferrous sulfate (1). Those given the iron supplements recorded improved scores for two-mile running tests and cognitive performance.

The researchers concluded that future efforts should identify and treat female soldiers or athletes who begin training regimens with iron deficiency or iron deficiency anemia. The effect of iron deficiency (ID) with anemia is well-documented and leads to reduced ability to do physical work.

Research indicates iron deficiency (ID) affects up to 16–21% of premenopausal women in the US and UK respectively, and it is thought iron deficiency may affect up to 50% of the world’s population, with the condition reaching pandemic status in the developing world. In the Western world it is a very female-centric problem: premenopausal women are at the greatest risk of ID because suboptimal iron consumption and menstrual bleeding lead to negative iron balance. Furthermore, premenopausal women who engage in regular physical activity may be at even greater risk of poor iron status because physical activity appears to have a negative effect on iron stores.


  1. McClung J. P. eta al. Randomized, double-blind, placebo-controlled trial of iron supplementation in female soldiers during military training: effects on iron status, physical performance, and mood. The American Journal of Clincial Nutrition, 2009; 90:1–8.