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Is your performance in the gym subpar? You could need more iron, suggests research published in the Journal of Nutrition.
According to the scientific review, iron supplementation improves women’s exercise performance, in terms of both the highest level they can achieve at 100% exertion or maximal capacity, and their exercise efficiency at a submaximal exertion.
“Our discovery of this effect is a new finding and should stimulate research to try to understand it better,” says lead author Sant-Rayn Pasricha, PhD, a post-doctoral fellow at the University of Melbourne. “The mechanism may relate to improved oxygen transport by improved hemoglobin (the protein that carries oxygen through the blood), or improved cardiac function due to direct effects of iron on the muscle.” Iron is very important to muscle, and is found in one of the major muscle proteins (myoglobin) as well as being critical in a range of metabolic processes. So extra iron in these sites may be beneficial for muscle function, he explains.
“Iron supplements are generally safe and have few serious side effects in most women,” Dr. Pasricha says. Unfortunately, those are gastrointestinal side effects that can be uncomfortable and possibly embarrassing—abdominal discomfort, constipation, diarrhea as well as a metallic taste in the mouth. “Finally, iron can be very toxic in overdose. Over the long term, use of iron supplements inappropriately might result in excessive iron stores—this can be prevented by regular monitoring and consultation with a doctor,” Dr. Pasricha says. The recommended daily allowance for women between the ages 19 and 50 is 18 mg.