ITHACA, N.Y. -- Women with low body iron, yet who are not anemic, have a much harder time sustaining exercise and adapting to training, concludes a new Cornell University study. But after a period of training, iron-deficient women who boost their body iron by taking supplements can improve their exercise endurance twice as much as iron-depleted women.
"Millions of women are working harder than they need in order to exercise or physically work, and they can't reap the benefits of endurance training as easily. As a result, exercise is more difficult so these women are more apt to lose their motivation to exercise," says Jere Haas, the Nancy Schlegel Meinig Professor of Maternal and Child Nutrition and director of the Division of Nutritional Sciences at Cornell.
Iron deficiency that is not as severe as anemia is a common problem, affecting about 16 percent of U.S. women and 40 to 80 percent of women in developing countries, most of whom are unaware of their condition. The new study, published in a recent issue of the Journal of Applied Physiology (Vol. 88, 2000), provides mounting evidence that iron depletion without anemia should be of greater concern. Other researchers have reported recently that moderate iron deficiency also compromises memory and verbal learning in teen-agers.
In a previous study, published in 1998, Haas found that iron-depletion in nonanemic women results in lower capacity for physical work and impaired exercise performance. The new study by Haas and three other researchers shows that iron deficiency impairs the ability to increase aerobic endurance after a period of exercise training. "In other words, we now know that iron-deficient women don't benefit from training as much as women with higher iron status because of impaired metabolic responses to exercise, but that iron supplementation can compensate," Haas says.
In the latest study, 42 iron-depleted (but not anemic) women aged 18 to 33 participated in a randomized, doubl
Contact: Susan S. Lang
Cornell University News Service