Daily iron supplementation significantly improves maximal and submaximal exercise performance in WRA , providing a rationale to prevent and treat iron deficiency in this group .
Animal and human observational studies suggest that iron deficiency impairs physical exercise performance , but findings from r and omized trials on the effects of iron are equivocal .
Iron deficiency and anemia are especially common in women of reproductive age ( WRA ) .
Clear evidence of benefit from iron supplementation would inform clinical and public health guidelines .
Therefore , we performed a systematic review and meta- analysis to determine the effect of iron supplementation compared with control on exercise performance in WRA .
Iron depletion without anemia and physical performance in young women.
Studies in laboratory animals found that iron deficiency without anemia decreased oxidative capacity and increased reliance on carbohydrate as the substrate for energy , thereby causing impaired endurance . The purpose of this cross-sectional study was to investigate the relation between iron deficiency without anemia and physical performance in healthy active women aged 19 - 36 y. Iron-status assessment included determination of hemoglobin , hematocrit , transferrin saturation , and serum ferritin values . Dietary iron intake was assessed by frequency question naires and physical activity level was estimated by frequency question naires and 2-wk records . Fifteen women with normal iron status and 15 women with iron depletion ( serum ferritin < 12 micrograms/L ) were chosen r and omly from a group of 69 nonanemic women and given physical-performance tests , including determinations of maximum oxygen consumption ( VO2max ) , ventilatory threshold , and delta-efficiency . There were no significant differences between the two groups in body size , body composition , physical activity level , dietary iron intake , delta-efficiency , or ventilatory threshold . Compared with the iron-depleted group , the iron-sufficient group had significantly higher hemoglobin , transferrin saturation , and serum ferritin values and a significantly greater tendency to use iron supplements . When physical activity level and fat-free mass were controlled for , the iron-depleted group had a significantly lower VO2max . The difference in VO2max was significantly associated with serum ferritin concentration ; hemoglobin value was not a significant confounder . Therefore , reduction of VO2max in nonanemic women with iron depletion was likely caused by factors related to reduced body iron storage but was unrelated to decreased oxygen-transport capacity of the blood
Daily iron supplementation significantly improves maximal and submaximal exercise performance in WRA , providing a rationale to prevent and treat iron deficiency in this group .
Animal and human observational studies suggest that iron deficiency impairs physical exercise performance , but findings from r and omized trials on the effects of iron are equivocal .
Iron deficiency and anemia are especially common in women of reproductive age ( WRA ) .
Clear evidence of benefit from iron supplementation would inform clinical and public health guidelines .
Therefore , we performed a systematic review and meta- analysis to determine the effect of iron supplementation compared with control on exercise performance in WRA .