Athletes in high-impact sports such as running.(Para. 6) sports that require great endurance The first and most common is having low iron reserves. a condition that typically has no symptoms.(Para. 7) The first stage of iron deficiency -which is also the most common is one in which one doesn't have much iron stored in the body. and during this stage there are usually no signs of iron deficiency. Note that "a condition that. 2 serves as an appositive generalizing the preceding clause.• Athletes in high-impact sports such as running… (Para. 6) sports that require great endurance The first and most common is having low iron reserves, a condition that typically has no symptoms. (Para. 7) The first stage of iron deficiency — which is also the most common — is one in which one doesn't have much iron stored in the body. And during this stage there are usually no signs of iron deficiency. Note that “a condition that…” serves as an appositive, generalizing the preceding clause