With female gymnasts, my main two nutrional concerns:
A good article on USolympicteam.com
Symptoms
The easiest symptom to notice associated with iron deficiency anemia is fatigue that worsens with exertion. Fatigue is common and can have many different causes (such as other nutritional imbalances, illness or stress). If an athlete experiences normal fatigue throughout the day and is not worsened with exercise, the cause is likely not iron deficiency by itself. The following are also possible symptoms of iron deficiency anemia:
Decreased performance Sleepiness and fatigue (outside of normal) Poor concentration Moodiness or irritability Always feeling cold
By Bob Seebohar, Fuel4mance – IRON DEFICIENCY ANEMIA AND PERFORMANCE
Gymnastics Coaching.com 