The purpose of the present study was to compare endocrine parameters reflecting 
reproductive function and metabolism in ten amenorrheic (AR) and eumenorrheic 
(ER) adolescent female runners and seven untrained controls (SE). Additionally, 
responses to diagnostic criteria for eating disorders (DSM-III) were compared 
among groups. AR ran more miles/day and consumed fewer kcal/d to support energy 
expenditure compared to ER (p < 0.05). Mean levels of fasting plasma estradiol, 
luteinizing hormone, follicle-stimulating hormone, free thyroxine and 
triiodothyronine were significantly lower in AR compared to ER and SE. AR 
indicated they were very concerned about their weight and were fearful of 
gaining fat mass. Female adolescents who participate in strenuous training 
exhibit alterations in hormone levels reflecting reproductive function and 
metabolism.