 Iron deficiency is known to negatively impact physical performance, attention, and time spent doing physical activity. As a result, an iron deficient person must expend more energy to complete the same amount of work as someone who is healthy. Another interesting relationship has been observed between exercise training and iron status in that women who participate in exercise training often have higher rates of iron deficiency than sedentary women. ID is commonly treated using daily iron supplementation. However, it is currently unknown whether participating in regular exercise somehow impacts the effectiveness of iron supplementation. Iron deficient women who participate in exercise programs may potentially benefit less from iron supplementation than those who do not. Another common treatment for the symptoms of iron deficiency is the traditional Chinese herbal treatment, Ba-Zhen-Ke-Li BZKL. While studies have shown that BZKL impacts expression of some iron-related proteins and increases endurance performance in rats, no studies have examined the efficacy of BZKL in improving iron markers or physical performance in humans. This study will compare the efficacy of BZKL in improving iron status and physical performance with that of ferrous sulfate supplementation. The Cornell research team will achieve these objectives in collaboration with colleagues at Kunming Medical University KMU in Kunming, China. A double-blind, randomized, placebo controlled study will be conducted by a Cornell graduate student at KMU. The subjects will be healthy women, age 18-26 years, attending KMU. Blood samples will be collected and analyzed for measures of iron. 