The purpose of this research study is to determine the importance and level of physical activity in people with Anorexia Nervosa.

A laboratory paradigm that uses a progressive ratio computerized work task will be used to determine the reinforcing value of exercise in hospitalized patients with AN, both before and after weight gain. In addition, we will examine the relationship between the reinforcing value of exercise and free-living physical activity in this population. We will also examine the relationship between the reinforcing value of exercise and measures of depression, anxiety, and cortisol, which we have found in previous studies to be associated with other measures of physical activity and exercise motivation. In order to determine whether physical activity in women with AN differs from that of non-eating disordered women, we will extend studies of physical activity to free-living control participants. All adult patients and controls will undergo body composition assessment once to measure the association between physical activity and percent body fat. Finally, to determine the impact of exercise reinforcement and physical activity on outcome in women with AN, we will conduct follow-up assessments in all patient participants for one year after discharge from the inpatient treatment unit."

Inclusion Criteria:

• DSM-IV diagnosis of Anorexia Nervosa (except amenorrhea)
• Female
• Age 18-45
• Medically Stable for exercise participation
• At a minimum of 75% Ideal Body Weight

Exclusion Criteria:

• Significant or current past medical illness including diabetes mellitis and heart disease
• Current or lifetime history or schizophrenia, bipolar disorder, or other psychotic disorder as defined by DSM-IV-TR
• Current suicidal ideation or recent suicidal behavior (within past 3 months)
• Drug or alcohol abuse in last 6 months
• Taking psychotropic medication
• Pregnancy

Participants will be patients with anorexia nervosa on the inpatient unit at New York State Psychiatric Institute